|
First Draft of Schematic. Using Lishen 202Ah. I decided to go with the BMS only actively controlling the charge side of the circuit and opted for passive monitoring on the load side. Using a victron 712 for monitoring and hopefully can connect it to a relay to shut off charge circuit at predetermined voltage. Guys please tell me what I have missed.
Couple of points.
1) Passive Load monitoring. I have decided to go this route as i understand that the load BMS can turn off for 2 reasons, obviously first is if whole bank drops to a lower than 20%SOC and secondly if single cells fail. From my perspective if I have a single cell failure I would rather still be able to use the other 15 cells than have no power. If I let my bank drop to below SOC of 20% that's?on me.
2) Want to keep house bank separate?for now, mainly as if I have to shut off my 48v bank for low SOC I don't want to have to worry about all my electronics being offline.
3) I want a separate?relay to shut off charge current so that I can set this manually. When I come back from a sail i want to be able to top bank up to about a 70% SOC for storage. Then on the day I want to sail I can top it off o 90%
|
Not trying to be nosey but what will t cost for your Lishen bank? Someone else I know has bought from them & they're very pleased with it.
First Draft of Schematic. Using Lishen 202Ah. I decided to go with the BMS only actively controlling the charge side of the circuit and opted for passive monitoring on the load side. Using a victron 712 for monitoring and hopefully can connect it to a relay to shut off charge circuit at predetermined voltage. Guys please tell me what I have missed.
Couple of points.
1) Passive Load monitoring. I have decided to go this route as i understand that the load BMS can turn off for 2 reasons, obviously first is if whole bank drops to a lower than 20%SOC and secondly if single cells fail. From my perspective if I have a single cell failure I would rather still be able to use the other 15 cells than have no power. If I let my bank drop to below SOC of 20% that's?on me.
2) Want to keep house bank separate?for now, mainly as if I have to shut off my 48v bank for low SOC I don't want to have to worry about all my electronics being offline.
3) I want a separate?relay to shut off charge current so that I can set this manually. When I come back from a sail i want to be able to top bank up to about a 70% SOC for storage. Then on the day I want to sail I can top it off o 90%
|
I actually bought 20 plus busbars so that I could keep a few spare. I paid $1437 for all 20 from Xuba on Alibaba, they all arrived yesterday. As easy as ordering on Amazon except for the wait.?
toggle quoted message
Show quoted text
Not trying to be nosey but what will t cost for your Lishen bank? Someone else I know has bought from them & they're very pleased with it.
First Draft of Schematic. Using Lishen 202Ah. I decided to go with the
BMS only actively controlling the charge side of the circuit and opted for passive monitoring on the load side. Using a victron 712 for monitoring and hopefully can connect it to a relay to shut off charge circuit at predetermined voltage. Guys please tell
me what I have missed.
Couple of points.
1) Passive Load monitoring. I have decided to go this
route as i understand that the load BMS can turn off for 2 reasons, obviously first is if whole bank drops to a lower than 20%SOC and secondly if single cells fail. From my perspective if I have a single cell failure I would rather still be able to use the
other 15 cells than have no power. If I let my bank drop to below SOC of 20% that's?on me.
2) Want to keep house bank separate?for now, mainly
as if I have to shut off my 48v bank for low SOC I don't want to have to worry about all my electronics being offline.
3) I want a separate?relay to shut off charge current
so that I can set this manually. When I come back from a sail i want to be able to top bank up to about a 70% SOC for storage. Then on the day I want to sail I can top it off o 90%
|
I wanted to comment on 1) below - we
have that same concept in mind.? We are working on a BMS design
that will basically allow cells to be "dropped out" of series, the
output run through a boost circuit to maintain steady voltage.?
There are of course limits to how many can drop out and we are
very much at the experimental stage here, but there is some hope
:)
Jeff LaCoursiere
s/v Angels Quest
First Draft of Schematic. Using
Lishen 202Ah. I decided to go with the BMS only actively
controlling the charge side of the circuit and opted for passive
monitoring on the load side. Using a victron 712 for monitoring
and hopefully can connect it to a relay to shut off charge
circuit at predetermined voltage. Guys please tell me what I
have missed.
Couple of points.
1) Passive Load
monitoring. I have decided to go this route as i understand
that the load BMS can turn off for 2 reasons, obviously
first is if whole bank drops to a lower than 20%SOC and
secondly if single cells fail. From my perspective if I have
a single cell failure I would rather still be able to use
the other 15 cells than have no power. If I let my bank drop
to below SOC of 20% that's?on me.
2) Want to keep
house bank separate?for now, mainly as if I have to shut off
my 48v bank for low SOC I don't want to have to worry about
all my electronics being offline.
3) I want a
separate?relay to shut off charge current so that I can set
this manually. When I come back from a sail i want to be
able to top bank up to about a 70% SOC for storage. Then on
the day I want to sail I can top it off o 90%
--
Jeff LaCoursiere
StratusTalk, Inc.
703 496 4990 x108
815 546 6599 cell
-- Jeff LaCoursiere s/v Angels Quest St Thomas USVI
|
Hi, Jeff
Did you experience single/multiple cell dropouts from Lishen batteries so far ?
On Thursday, 29 April 2021, 23:22:13 GMT+8, Jeff LaCoursiere <jeff@...> wrote:
I wanted to comment on 1) below - we
have that same concept in mind.? We are working on a BMS design
that will basically allow cells to be "dropped out" of series, the
output run through a boost circuit to maintain steady voltage.?
There are of course limits to how many can drop out and we are
very much at the experimental stage here, but there is some hope
:)
Jeff LaCoursiere
s/v Angels Quest
First Draft of Schematic. Using
Lishen 202Ah. I decided to go with the BMS only actively
controlling the charge side of the circuit and opted for passive
monitoring on the load side. Using a victron 712 for monitoring
and hopefully can connect it to a relay to shut off charge
circuit at predetermined voltage. Guys please tell me what I
have missed.
Couple of points.
1) Passive Load
monitoring. I have decided to go this route as i understand
that the load BMS can turn off for 2 reasons, obviously
first is if whole bank drops to a lower than 20%SOC and
secondly if single cells fail. From my perspective if I have
a single cell failure I would rather still be able to use
the other 15 cells than have no power. If I let my bank drop
to below SOC of 20% that's?on me.
2) Want to keep
house bank separate?for now, mainly as if I have to shut off
my 48v bank for low SOC I don't want to have to worry about
all my electronics being offline.
3) I want a
separate?relay to shut off charge current so that I can set
this manually. When I come back from a sail i want to be
able to top bank up to about a 70% SOC for storage. Then on
the day I want to sail I can top it off o 90%
--
Jeff LaCoursiere
StratusTalk, Inc.
703 496 4990 x108
815 546 6599 cell
--
Jeff LaCoursiere
s/v Angels Quest
St Thomas USVI
|
I like your diagram.? I have a couple questions.???
You show the shunt for the monitor between the BMS and the neg lead.? That makes sense but it can't be done that way on a battery like a Battleborn with its internal BMS.? So I wonder which way is better?? Should the BMS be considered a part of the battery??? So the battery is in effect a box with all the BMS components inside.?
You show a separate negative lead to the BMS from the charger?? Does your BMS have a seperate neg input fro the charger?
What BMS are you planning this with?
Thanks, Dan Pfeiffer
?
toggle quoted message
Show quoted text
On 2021-04-29 10:06 am, oreillygb@... wrote:
First Draft of Schematic. Using Lishen 202Ah. I decided to go with the BMS only actively controlling the charge side of the circuit and opted for passive monitoring on the load side. Using a victron 712 for monitoring and hopefully can connect it to a relay to shut off charge circuit at predetermined voltage. Guys please tell me what I have missed.
Couple of points.
1) Passive Load monitoring. I have decided to go this route as i understand that the load BMS can turn off for 2 reasons, obviously first is if whole bank drops to a lower than 20%SOC and secondly if single cells fail. From my perspective if I have a single cell failure I would rather still be able to use the other 15 cells than have no power. If I let my bank drop to below SOC of 20% that's?on me.
2) Want to keep house bank separate?for now, mainly as if I have to shut off my 48v bank for low SOC I don't want to have to worry about all my electronics being offline.
3) I want a separate?relay to shut off charge current so that I can set this manually. When I come back from a sail i want to be able to top bank up to about a 70% SOC for storage. Then on the day I want to sail I can top it off o 90%
|
We haven't had any bad cells imported yet, knock wood.? We *are*
doing our best to burn down our offices with our BMS experiments
though :)? Also, our latest batch was all EVE 280AH cells, the
Lishen 272AH are apparently "all gone".
Another cool idea we are kicking around... we want our 48v pack
to have a 12v tap, so you can use it as your house battery as well
as your traction battery.? I'm disappointed in the available
downconverters, mostly current limited to 30-60A.? Maybe that
would be enough for your house, but it wouldn't do it for mine.
So we want to try to cycle through internal banks of four cells,
very quickly (like 10khz), connecting them in turn to the 12v
tap.? We believe that this way you will be able to pull the full
1C discharge of the 16 cell pack (280A), but at 12v!? We hope to
maintain balance in discharge by cycling very fast, but the BMS
should pick up the slack.
Cheers,
Jeff LaCoursiere
s/v Angels Quest
On 4/29/21 11:34 AM, Carsten via
groups.io wrote:
Hi, Jeff
Did you experience
single/multiple cell dropouts from Lishen batteries so far ?
On Thursday, 29 April 2021, 23:22:13 GMT+8, Jeff
LaCoursiere <jeff@...>
wrote:
I
wanted to comment on 1) below - we have that same
concept in mind.? We are working on a BMS design that
will basically allow cells to be "dropped out" of
series, the output run through a boost circuit to
maintain steady voltage.? There are of course limits
to how many can drop out and we are very much at the
experimental stage here, but there is some hope :)
Jeff
LaCoursiere
s/v
Angels Quest
First
Draft of Schematic. Using Lishen 202Ah. I decided to
go with the BMS only actively controlling the charge
side of the circuit and opted for passive monitoring
on the load side. Using a victron 712 for monitoring
and hopefully can connect it to a relay to shut off
charge circuit at predetermined voltage. Guys please
tell me what I have missed.
Couple
of points.
1) Passive Load
monitoring. I have decided to go this route as i
understand that the load BMS can turn off for 2
reasons, obviously first is if whole bank drops to
a lower than 20%SOC and secondly if single cells
fail. From my perspective if I have a single cell
failure I would rather still be able to use the
other 15 cells than have no power. If I let my
bank drop to below SOC of 20% that's?on me.
2) Want to keep house bank
separate?for now, mainly as if I have to shut off
my 48v bank for low SOC I don't want to have to
worry about all my electronics being offline.
3) I want a separate?relay
to shut off charge current so that I can set this
manually. When I come back from a sail i want to
be able to top bank up to about a 70% SOC for
storage. Then on the day I want to sail I can top
it off o 90%
--
Jeff LaCoursiere
StratusTalk, Inc.
703 496 4990 x108
815 546 6599 cell
--
Jeff LaCoursiere
s/v Angels Quest
St Thomas USVI
--
 |
Jeff LaCoursiere
STRATUSTALK, INC. / CTO
| Phone: |
+1
703.496.4990 x108 |
| Mobile: |
+1
815.546.6599 |
| Email: |
jeff@...
|
| Website: |
|
| Address: |
One
Freedom Square
13th Floor
Reston, VA 20190 |
|
| ? ? ? |
-- Jeff LaCoursiere s/v Angels Quest St Thomas USVI
|
I am skeptical of passive load monitoring. Your reasons for choosing it are all about the pack. What about the load? What if your motor controller fails and wants to short the pack? With passive monitoring, there is no protection. There is also no guarantee that you will be attentive to a load issue when it occurs. You might have your hands full with other aspects of the situation.
I understand about not wanting to be stuck because of one bad cell. Maybe some sort of BMS bypass on the load side might be a reasonable compromise? If your BMS shuts down while using the pack, assess the situation, resolve it, or proceed carefully on bypass if needed.
I added a bypass on the charging side, since I use a solar charger, and never want to get stuck because the pack voltage was too low and the BMS wouldn't let the charger charge it.
Interesting that I destroyed two cells when I tried to do passive monitoring. Since installing the BMS between the charging and load circuits and the pack, I've had no problems. Maybe it's a karma thing?
|
Interesting, Jeff ! 12V sucked from 48V, without an inverter ! Thumbs up !
In your intended setup of your battery banks, do you use 1 common BMS, or 1 on each (48V) battery ? How about redundancy, if a common BMS fails ? (= no power at all.)
Another thing, how about making the motor wattage output adjustable, so it is possible to use eg. 96V for a burst mode ? Many 48V motors can be powered by 96V (or higher).
I assume that the wiring can handle that. Making two sets of banks 48V, to be serial connected to 96V. The short "event" should of course be managed by the BMS/power management system.
i'm wondering if this new Li-battery technology is becoming a little too advanced for sailing now... Safety first, when out on the water, right ? We can't just park the boat at the curb and call a cab when out on the blue.
To be true, things made in China is not my cup of tea, but in these days, unfortunately simply unavoidable !
I was a supervisor in China for several years, and know how they make things, and all of QC is not like in the West. Buy a ME1616 electromotor. Made in China, then sold in the West.
Buy yourself a german or US car. Half of the smaller parts in it are made in China by now.
Company supervisors are not in China now, because of the Made in China virus. Who wants to spend 2-4 weeks in quarantine to go for an inspection ??
Who's checking the quality now ?
However, I believe that new, checked, LiFePO4 batteries will last my sailing life out, but the electronics is another concern. Especially in a marine environment (humid and salty). Can you provide recommendations where to setup these (rather large) electronic regulators/inverters/BMS'es in the boat ? I guess IP rating is not relevant, if not encapsuled in IP-rated boxes. If put into boxes, then there's a cooling issue...
Working hard on the ultimate solution for my own EMS/Y system conversion design.
Cheers, guys
Carsten
Hint : EMS/Y = Electric Motor Sailing Yacht ;-)
On Friday, 30 April 2021, 02:46:25 GMT+8, Jeff LaCoursiere <jeff@...> wrote:
We haven't had any bad cells imported yet, knock wood.? We *are*
doing our best to burn down our offices with our BMS experiments
though :)? Also, our latest batch was all EVE 280AH cells, the
Lishen 272AH are apparently "all gone".
Another cool idea we are kicking around... we want our 48v pack
to have a 12v tap, so you can use it as your house battery as well
as your traction battery.? I'm disappointed in the available
downconverters, mostly current limited to 30-60A.? Maybe that
would be enough for your house, but it wouldn't do it for mine.
So we want to try to cycle through internal banks of four cells,
very quickly (like 10khz), connecting them in turn to the 12v
tap.? We believe that this way you will be able to pull the full
1C discharge of the 16 cell pack (280A), but at 12v!? We hope to
maintain balance in discharge by cycling very fast, but the BMS
should pick up the slack.
Cheers,
Jeff LaCoursiere
s/v Angels Quest
On 4/29/21 11:34 AM, Carsten via
groups.io wrote:
Hi, Jeff
Did you experience
single/multiple cell dropouts from Lishen batteries so far ?
On Thursday, 29 April 2021, 23:22:13 GMT+8, Jeff
LaCoursiere <jeff@...>
wrote:
I
wanted to comment on 1) below - we have that same
concept in mind.? We are working on a BMS design that
will basically allow cells to be "dropped out" of
series, the output run through a boost circuit to
maintain steady voltage.? There are of course limits
to how many can drop out and we are very much at the
experimental stage here, but there is some hope :)
Jeff
LaCoursiere
s/v
Angels Quest
First
Draft of Schematic. Using Lishen 202Ah. I decided to
go with the BMS only actively controlling the charge
side of the circuit and opted for passive monitoring
on the load side. Using a victron 712 for monitoring
and hopefully can connect it to a relay to shut off
charge circuit at predetermined voltage. Guys please
tell me what I have missed.
Couple
of points.
1) Passive Load
monitoring. I have decided to go this route as i
understand that the load BMS can turn off for 2
reasons, obviously first is if whole bank drops to
a lower than 20%SOC and secondly if single cells
fail. From my perspective if I have a single cell
failure I would rather still be able to use the
other 15 cells than have no power. If I let my
bank drop to below SOC of 20% that's?on me.
2) Want to keep house bank
separate?for now, mainly as if I have to shut off
my 48v bank for low SOC I don't want to have to
worry about all my electronics being offline.
3) I want a separate?relay
to shut off charge current so that I can set this
manually. When I come back from a sail i want to
be able to top bank up to about a 70% SOC for
storage. Then on the day I want to sail I can top
it off o 90%
--
Jeff LaCoursiere
StratusTalk, Inc.
703 496 4990 x108
815 546 6599 cell
--
Jeff LaCoursiere
s/v Angels Quest
St Thomas USVI
--
![]() | Jeff LaCoursiere
STRATUSTALK, INC. / CTO
| Phone: | +1
703.496.4990 x108 | | Mobile: | +1
815.546.6599 | | Email: | jeff@...
| | Website: | | | Address: | One
Freedom Square
13th Floor
Reston, VA 20190 |
| | ? ? ? |
--
Jeff LaCoursiere
s/v Angels Quest
St Thomas USVI
|
Oh man are you preaching to the choir
here.? I get so frustrated - we are doing what I feel is cutting
edge stuff, and it requires components and tools that you simply
cannot buy anywhere else.? Perfect example that blew me away last
week.? We have a lead on making drop-in replacements for 8D
batteries.? We hadn't really planned to go this route, but why
not?? So I start looking for empty 8D battery cases (note - not an
8D battery BOX, of which you can find many, that is what the 8D
case will go into for "protection").
A bunch on ebay, but every single one
is either from China or being distributed by someone who got it
from China.
Do a web search - there simply aren't
any US companies making these plastic boxes.? Why the heck not??
In the end I ordered some from appbattery.com, and will twiddle my
thumbs for the next month until they get here.
Chargers, balancing circuits, cell
protection circuits... ALL of this stuff, only from China.
It makes me think that we are way more
dependent than most realize!
Great ideas below, by the way, we will
noodle on them and make some comments :)
Jeff LaCoursiere
s/v Angels Quest
On 4/30/21 11:38 AM, Carsten via
groups.io wrote:
Interesting, Jeff !
12V sucked from 48V, without
an inverter ! Thumbs up !
In your intended setup of
your battery banks, do you use 1 common BMS, or 1 on each
(48V) battery ?
How about redundancy, if a
common BMS fails ? (= no power at all.)
Another thing, how about
making the motor wattage output adjustable, so it is possible
to use eg. 96V for a burst mode ? Many 48V motors can be
powered by 96V (or higher).
I assume that the wiring can
handle that. Making two sets of banks 48V, to be serial
connected to 96V.
The short "event" should of
course be managed by the BMS/power management system.
i'm wondering if this new
Li-battery technology is becoming a little too advanced for
sailing now...
Safety first, when out on the
water, right ? We can't just park the boat at the curb and
call a cab when out on the blue.
To be true, things made in
China is not my cup of tea, but in these days, unfortunately
simply unavoidable !
I was a supervisor in China
for several years, and know how they make things, and all of
QC is not like in the West.
Buy a ME1616 electromotor.
Made in China, then sold in the West.
Buy yourself a german or US
car. Half of the smaller parts in it are made in China by now.
Company supervisors are not
in China now, because of the Made in China virus.
Who wants to spend 2-4 weeks
in quarantine to go for an inspection ??
Who's checking the quality
now ?
However, I believe that new,
checked, LiFePO4 batteries will last my sailing life out, but
the electronics is another concern.
Especially in a marine
environment (humid and salty).
Can you provide
recommendations where to setup these (rather large) electronic
regulators/inverters/BMS'es in the boat ?
I guess IP rating is not
relevant, if not encapsuled in IP-rated boxes.
If put into boxes, then
there's a cooling issue...
Working hard on the ultimate
solution for my own EMS/Y system conversion design.
Cheers, guys
Carsten
Hint : EMS/Y = Electric Motor
Sailing Yacht ;-)
On Friday, 30 April 2021, 02:46:25 GMT+8, Jeff
LaCoursiere <jeff@...> wrote:
We haven't had any bad cells imported yet, knock
wood.? We *are* doing our best to burn down our offices
with our BMS experiments though :)? Also, our latest
batch was all EVE 280AH cells, the Lishen 272AH are
apparently "all gone".
Another cool idea we are kicking around... we want
our 48v pack to have a 12v tap, so you can use it as
your house battery as well as your traction battery.?
I'm disappointed in the available downconverters,
mostly current limited to 30-60A.? Maybe that would be
enough for your house, but it wouldn't do it for mine.
So we want to try to cycle through internal banks of
four cells, very quickly (like 10khz), connecting them
in turn to the 12v tap.? We believe that this way you
will be able to pull the full 1C discharge of the 16
cell pack (280A), but at 12v!? We hope to maintain
balance in discharge by cycling very fast, but the BMS
should pick up the slack.
Cheers,
Jeff LaCoursiere
s/v Angels Quest
On
4/29/21 11:34 AM, Carsten via groups.io wrote:
Hi, Jeff
Did you experience single/multiple cell
dropouts from Lishen batteries so far ?
On Thursday, 29 April 2021, 23:22:13 GMT+8,
Jeff LaCoursiere <jeff@...>
wrote:
I
wanted to comment on 1) below - we have that
same concept in mind.? We are working on a
BMS design that will basically allow cells
to be "dropped out" of series, the output
run through a boost circuit to maintain
steady voltage.? There are of course limits
to how many can drop out and we are very
much at the experimental stage here, but
there is some hope :)
Jeff
LaCoursiere
s/v
Angels Quest
First
Draft of Schematic. Using Lishen 202Ah. I
decided to go with the BMS only actively
controlling the charge side of the circuit
and opted for passive monitoring on the load
side. Using a victron 712 for monitoring and
hopefully can connect it to a relay to shut
off charge circuit at predetermined voltage.
Guys please tell me what I have missed.
Couple
of points.
1)
Passive Load monitoring. I have decided
to go this route as i understand that
the load BMS can turn off for 2 reasons,
obviously first is if whole bank drops
to a lower than 20%SOC and secondly if
single cells fail. From my perspective
if I have a single cell failure I would
rather still be able to use the other 15
cells than have no power. If I let my
bank drop to below SOC of 20% that's?on
me.
2)
Want to keep house bank separate?for
now, mainly as if I have to shut off my
48v bank for low SOC I don't want to
have to worry about all my electronics
being offline.
3)
I want a separate?relay to shut off
charge current so that I can set this
manually. When I come back from a sail i
want to be able to top bank up to about
a 70% SOC for storage. Then on the day I
want to sail I can top it off o 90%
--
Jeff LaCoursiere
StratusTalk, Inc.
703 496 4990 x108
815 546 6599 cell
--
Jeff LaCoursiere
s/v Angels Quest
St Thomas USVI
--
![]() |
Jeff LaCoursiere
STRATUSTALK, INC. / CTO
| Phone: |
+1 703.496.4990
x108 |
| Mobile: |
+1 815.546.6599 |
| Email: |
jeff@...
|
| Website: |
|
| Address: |
One Freedom
Square
13th Floor
Reston, VA 20190 |
|
| ? ? ? |
--
Jeff LaCoursiere
s/v Angels Quest
St Thomas USVI
--
Jeff LaCoursiere
StratusTalk, Inc.
703 496 4990 x108
815 546 6599 cell
-- Jeff LaCoursiere s/v Angels Quest St Thomas USVI
|
Anyone considering going all electric propulsion in the salty
ocean environment is being naive. The IC and computer components
will corrode unless sealed circuit board tech, like in military,
automotive ECUs and even in residential clothes dryers is used.
That makes repair maintenance difficult....unless spare sealed
circuit boards can be easily swapped? out.
On 30/04/2021 11:02 a.m., Jeff
LaCoursiere wrote:
toggle quoted message
Show quoted text
Oh man are you preaching to the choir
here.? I get so frustrated - we are doing what I feel is cutting
edge stuff, and it requires components and tools that you simply
cannot buy anywhere else.? Perfect example that blew me away
last week.? We have a lead on making drop-in replacements for 8D
batteries.? We hadn't really planned to go this route, but why
not?? So I start looking for empty 8D battery cases (note - not
an 8D battery BOX, of which you can find many, that is what the
8D case will go into for "protection").
computer compenent
A bunch on ebay, but every single one
is either from China or being distributed by someone who got it
from China.
Do a web search - there simply aren't
any US companies making these plastic boxes.? Why the heck not??
In the end I ordered some from appbattery.com, and will twiddle
my thumbs for the next month until they get here.
Chargers, balancing circuits, cell
protection circuits... ALL of this stuff, only from China.
It makes me think that we are way
more dependent than most realize!
Great ideas below, by the way, we
will noodle on them and make some comments :)
Jeff LaCoursiere
s/v Angels Quest
On 4/30/21 11:38 AM, Carsten via
groups.io wrote:
Interesting, Jeff !
12V sucked from 48V,
without an inverter ! Thumbs up !
In your intended setup of
your battery banks, do you use 1 common BMS, or 1 on each
(48V) battery ?
How about redundancy, if a
common BMS fails ? (= no power at all.)
Another thing, how about
making the motor wattage output adjustable, so it is
possible to use eg. 96V for a burst mode ? Many 48V motors
can be powered by 96V (or higher).
I assume that the wiring
can handle that. Making two sets of banks 48V, to be serial
connected to 96V.
The short "event" should of
course be managed by the BMS/power management system.
i'm wondering if this new
Li-battery technology is becoming a little too advanced for
sailing now...
Safety first, when out on
the water, right ? We can't just park the boat at the curb
and call a cab when out on the blue.
To be true, things made in
China is not my cup of tea, but in these days, unfortunately
simply unavoidable !
I was a supervisor in China
for several years, and know how they make things, and all of
QC is not like in the West.
Buy a ME1616 electromotor.
Made in China, then sold in the West.
Buy yourself a german or US
car. Half of the smaller parts in it are made in China by
now.
Company supervisors are not
in China now, because of the Made in China virus.
Who wants to spend 2-4
weeks in quarantine to go for an inspection ??
Who's checking the quality
now ?
However, I believe that
new, checked, LiFePO4 batteries will last my sailing life
out, but the electronics is another concern.
Especially in a marine
environment (humid and salty).
Can you provide
recommendations where to setup these (rather large)
electronic regulators/inverters/BMS'es in the boat ?
I guess IP rating is not
relevant, if not encapsuled in IP-rated boxes.
If put into boxes, then
there's a cooling issue...
Working hard on the
ultimate solution for my own EMS/Y system conversion design.
Cheers, guys
Carsten
Hint : EMS/Y = Electric
Motor Sailing Yacht ;-)
On Friday, 30 April 2021, 02:46:25 GMT+8, Jeff
LaCoursiere <jeff@...>
wrote:
We haven't had any bad cells imported yet, knock
wood.? We *are* doing our best to burn down our
offices with our BMS experiments though :)? Also, our
latest batch was all EVE 280AH cells, the Lishen 272AH
are apparently "all gone".
Another cool idea we are kicking around... we want
our 48v pack to have a 12v tap, so you can use it as
your house battery as well as your traction
battery.? I'm disappointed in the available
downconverters, mostly current limited to 30-60A.?
Maybe that would be enough for your house, but it
wouldn't do it for mine.
So we want to try to cycle through internal banks
of four cells, very quickly (like 10khz), connecting
them in turn to the 12v tap.? We believe that this
way you will be able to pull the full 1C discharge
of the 16 cell pack (280A), but at 12v!? We hope to
maintain balance in discharge by cycling very fast,
but the BMS should pick up the slack.
Cheers,
Jeff LaCoursiere
s/v Angels Quest
On
4/29/21 11:34 AM, Carsten via groups.io wrote:
Hi, Jeff
Did you experience single/multiple
cell dropouts from Lishen batteries so far ?
On Thursday, 29 April 2021, 23:22:13 GMT+8,
Jeff LaCoursiere <jeff@...>
wrote:
I
wanted to comment on 1) below - we have
that same concept in mind.? We are working
on a BMS design that will basically allow
cells to be "dropped out" of series, the
output run through a boost circuit to
maintain steady voltage.? There are of
course limits to how many can drop out and
we are very much at the experimental stage
here, but there is some hope :)
Jeff
LaCoursiere
s/v
Angels Quest
First
Draft of Schematic. Using Lishen 202Ah. I
decided to go with the BMS only actively
controlling the charge side of the circuit
and opted for passive monitoring on the
load side. Using a victron 712 for
monitoring and hopefully can connect it to
a relay to shut off charge circuit at
predetermined voltage. Guys please tell me
what I have missed.
Couple
of points.
1) Passive
Load monitoring. I have decided to go
this route as i understand that the
load BMS can turn off for 2 reasons,
obviously first is if whole bank drops
to a lower than 20%SOC and secondly if
single cells fail. From my perspective
if I have a single cell failure I
would rather still be able to use the
other 15 cells than have no power. If
I let my bank drop to below SOC of 20%
that's?on me.
2) Want to
keep house bank separate?for now,
mainly as if I have to shut off my 48v
bank for low SOC I don't want to have
to worry about all my electronics
being offline.
3) I want a
separate?relay to shut off charge
current so that I can set this
manually. When I come back from a sail
i want to be able to top bank up to
about a 70% SOC for storage. Then on
the day I want to sail I can top it
off o 90%
--
Jeff LaCoursiere
StratusTalk, Inc.
703 496 4990 x108
815 546 6599 cell
--
Jeff LaCoursiere
s/v Angels Quest
St Thomas USVI
--
![]() |
Jeff LaCoursiere
STRATUSTALK, INC. / CTO
| Phone: |
+1 703.496.4990
x108 |
| Mobile: |
+1 815.546.6599 |
| Email: |
jeff@...
|
| Website: |
|
| Address: |
One Freedom
Square
13th Floor
Reston, VA 20190 |
|
| ?
?
?
|
--
Jeff LaCoursiere
s/v Angels Quest
St Thomas USVI
--
Jeff LaCoursiere
StratusTalk, Inc.
703 496 4990 x108
815 546 6599 cell
--
Jeff LaCoursiere
s/v Angels Quest
St Thomas USVI
|
This sounds really useful. ?
And I wonder - At the “whole boat scale” - since its likely all going to be stationary, couldn’t you just provide a couple of circuits with downconverters or do you have individual loads that are > 60a? ?This is what I’ve done recently when deciding to setup another boat with a single large 48v bank.?
I also considered 80a downconverters, but decided I didn’t need them. ?One place for those is here:??
I did wonder but haven’t tried to figure out if you could run the DCDC converters in parallel, do you know?
toggle quoted message
Show quoted text
On Apr 29, 2021, at 11:46 AM, Jeff LaCoursiere < jeff@...> wrote:
We haven't had any bad cells imported yet, knock wood.? We *are*
doing our best to burn down our offices with our BMS experiments
though :)? Also, our latest batch was all EVE 280AH cells, the
Lishen 272AH are apparently "all gone". Another cool idea we are kicking around... we want our 48v pack
to have a 12v tap, so you can use it as your house battery as well
as your traction battery.? I'm disappointed in the available
downconverters, mostly current limited to 30-60A.? Maybe that
would be enough for your house, but it wouldn't do it for mine. So we want to try to cycle through internal banks of four cells,
very quickly (like 10khz), connecting them in turn to the 12v
tap.? We believe that this way you will be able to pull the full
1C discharge of the 16 cell pack (280A), but at 12v!? We hope to
maintain balance in discharge by cycling very fast, but the BMS
should pick up the slack.
Cheers,
Jeff LaCoursiere
s/v Angels Quest
On 4/29/21 11:34 AM, Carsten via
wrote:
Hi, Jeff
Did you experience
single/multiple cell dropouts from Lishen batteries so far ?
On Thursday, 29 April 2021, 23:22:13 GMT+8, Jeff
LaCoursiere <jeff@...>
wrote:
I
wanted to comment on 1) below - we have that same
concept in mind.? We are working on a BMS design that
will basically allow cells to be "dropped out" of
series, the output run through a boost circuit to
maintain steady voltage.? There are of course limits
to how many can drop out and we are very much at the
experimental stage here, but there is some hope :)
Jeff
LaCoursiere
s/v
Angels Quest
First
Draft of Schematic. Using Lishen 202Ah. I decided to
go with the BMS only actively controlling the charge
side of the circuit and opted for passive monitoring
on the load side. Using a victron 712 for monitoring
and hopefully can connect it to a relay to shut off
charge circuit at predetermined voltage. Guys please
tell me what I have missed.
Couple
of points.
1) Passive Load
monitoring. I have decided to go this route as i
understand that the load BMS can turn off for 2
reasons, obviously first is if whole bank drops to
a lower than 20%SOC and secondly if single cells
fail. From my perspective if I have a single cell
failure I would rather still be able to use the
other 15 cells than have no power. If I let my
bank drop to below SOC of 20% that's?on me.
2) Want to keep house bank
separate?for now, mainly as if I have to shut off
my 48v bank for low SOC I don't want to have to
worry about all my electronics being offline.
3) I want a separate?relay
to shut off charge current so that I can set this
manually. When I come back from a sail i want to
be able to top bank up to about a 70% SOC for
storage. Then on the day I want to sail I can top
it off o 90%
--
Jeff LaCoursiere
StratusTalk, Inc.
703 496 4990 x108
815 546 6599 cell
--
Jeff LaCoursiere
s/v Angels Quest
St Thomas USVI
--
| |
Jeff LaCoursiere
STRATUSTALK, INC. / CTO
| Phone: |
+1
703.496.4990 x108 |
| Mobile: |
+1
815.546.6599 |
| Email: |
jeff@...
|
| Website: |
|
| Address: |
One
Freedom Square
13th Floor
Reston, VA 20190 |
|
| ? ? ? |
-- Jeff LaCoursiere s/v Angels Quest St Thomas USVI
|
Another thing, how about making the motor wattage output adjustable, so it is possible to use eg. 96V for a burst mode ? Many 48V motors can be powered by 96V (or higher).
I assume that the wiring can handle that. Making two sets of banks 48V, to be serial connected to 96V. The short "event" should of course be managed by the BMS/power management system.
This is interesting and something Ive wondered about but from what I’ve been able to discern it requires dynamically reprogramming the motor controller. ?You could imagine a switching setup that let you have 48v traction banks in parallel but then to change them to series. ?I wasn’t able to figure out a way to use the Seven Gen4 to do this kind of thing, at least from reading the manual. ?I fear I am about to venture into the world of the DVT software though and maybe its capable of that. I suppose if a person spent enough on controllers and cables you could have a dual system with two controllers and switch between them but I think you approach the point of diminishing returns.?
However, it points to a possible opportunity or maybe just a future feature that advanced motor controllers will enable. ?With EV regen becoming more popular in controllers, I would not be surprised if some battery management features also start to migrate to controllers as well.?
To be true, things made in China is not my cup of tea, but in these days, unfortunately simply unavoidable !
I was a supervisor in China for several years, and know how they make things, and all of QC is not like in the West. Buy a ME1616 electromotor. Made in China, then sold in the West.
Buy yourself a german or US car. Half of the smaller parts in it are made in China by now.
Company supervisors are not in China now, because of the Made in China virus.
Who wants to spend 2-4 weeks in quarantine to go for an inspection ??
Who's checking the quality now ?
As I spin up my own commercial efforts I have been working with colleagues in CN to understand the quality dynamics and the manufacturing landscape and while I think some of these comments are in a general sense applicable, I think that the demands of growing sophistication in their domestic market, growing domestic regulatory regime, and a drive to differentiate by rising to the QC and supply chain standards of Korea, Japan, US, and Europe is pressuring a lot of CN companies to advance. ?I think now it is more a story of doing homework to understand your partners and their processes.
Now, the current chaos of the global shipping / logistics is another story! The Suez Canal incident has cost me several weeks and the knock-on effects will continue for months.? However, I believe that new, checked, LiFePO4 batteries will last my sailing life out, but the electronics is another concern. Especially in a marine environment (humid and salty). Can you provide recommendations where to setup these (rather large) electronic regulators/inverters/BMS'es in the boat ? I guess IP rating is not relevant, if not encapsuled in IP-rated boxes. If put into boxes, then there's a cooling issue...
As far from any wet bilge or dripping shaft or outdoor moisture as possible. ?In the cabin if you can. If exposed to moist air frequently try running some electric air warmer/dryers or a dehumidifier (when on shore power).?
Working hard on the ultimate solution for my own EMS/Y system conversion design.
Cheers, guys
Carsten
Hint : EMS/Y = Electric Motor Sailing Yacht ;-)
On Friday, 30 April 2021, 02:46:25 GMT+8, Jeff LaCoursiere < jeff@...> wrote:
We haven't had any bad cells imported yet, knock wood.? We *are*
doing our best to burn down our offices with our BMS experiments
though :)? Also, our latest batch was all EVE 280AH cells, the
Lishen 272AH are apparently "all gone". Another cool idea we are kicking around... we want our 48v pack
to have a 12v tap, so you can use it as your house battery as well
as your traction battery.? I'm disappointed in the available
downconverters, mostly current limited to 30-60A.? Maybe that
would be enough for your house, but it wouldn't do it for mine. So we want to try to cycle through internal banks of four cells,
very quickly (like 10khz), connecting them in turn to the 12v
tap.? We believe that this way you will be able to pull the full
1C discharge of the 16 cell pack (280A), but at 12v!? We hope to
maintain balance in discharge by cycling very fast, but the BMS
should pick up the slack.
Cheers,
Jeff LaCoursiere
s/v Angels Quest
On 4/29/21 11:34 AM, Carsten via
wrote:
Hi, Jeff
Did you experience
single/multiple cell dropouts from Lishen batteries so far ?
On Thursday, 29 April 2021, 23:22:13 GMT+8, Jeff
LaCoursiere <jeff@...>
wrote:
I
wanted to comment on 1) below - we have that same
concept in mind.? We are working on a BMS design that
will basically allow cells to be "dropped out" of
series, the output run through a boost circuit to
maintain steady voltage.? There are of course limits
to how many can drop out and we are very much at the
experimental stage here, but there is some hope :)
Jeff
LaCoursiere
s/v
Angels Quest
First
Draft of Schematic. Using Lishen 202Ah. I decided to
go with the BMS only actively controlling the charge
side of the circuit and opted for passive monitoring
on the load side. Using a victron 712 for monitoring
and hopefully can connect it to a relay to shut off
charge circuit at predetermined voltage. Guys please
tell me what I have missed.
Couple
of points.
1) Passive Load
monitoring. I have decided to go this route as i
understand that the load BMS can turn off for 2
reasons, obviously first is if whole bank drops to
a lower than 20%SOC and secondly if single cells
fail. From my perspective if I have a single cell
failure I would rather still be able to use the
other 15 cells than have no power. If I let my
bank drop to below SOC of 20% that's?on me.
2) Want to keep house bank
separate?for now, mainly as if I have to shut off
my 48v bank for low SOC I don't want to have to
worry about all my electronics being offline.
3) I want a separate?relay
to shut off charge current so that I can set this
manually. When I come back from a sail i want to
be able to top bank up to about a 70% SOC for
storage. Then on the day I want to sail I can top
it off o 90%
--
Jeff LaCoursiere
StratusTalk, Inc.
703 496 4990 x108
815 546 6599 cell
--
Jeff LaCoursiere
s/v Angels Quest
St Thomas USVI
--
![]() | Jeff LaCoursiere
STRATUSTALK, INC. / CTO
| Phone: | +1
703.496.4990 x108 | | Mobile: | +1
815.546.6599 | | Email: | jeff@...
| | Website: | | | Address: | One
Freedom Square
13th Floor
Reston, VA 20190 |
| | ? ? ? |
--
Jeff LaCoursiere
s/v Angels Quest
St Thomas USVI
|
The other thing about 48v vs 96v is really why not just run at 96v the whole time. Basically if you are making it possible then all the rest of the system has to be specd to 96v and I don’t see the reason to not keep it that way??
toggle quoted message
Show quoted text
On Apr 30, 2021, at 11:12, Ryan Sweet via groups.io <ryan@...> wrote:
?
Another thing, how about making the motor wattage output adjustable, so it is possible to use eg. 96V for a burst mode ? Many 48V motors can be powered by 96V (or higher).
I assume that the wiring can handle that. Making two sets of banks 48V, to be serial connected to 96V. The short "event" should of course be managed by the BMS/power management system.
This is interesting and something Ive wondered about but from what I’ve been able to discern it requires dynamically reprogramming the motor controller. ?You could imagine a switching setup that let you have 48v traction banks in parallel but then to change them to series. ?I wasn’t able to figure out a way to use the Seven Gen4 to do this kind of thing, at least from reading the manual. ?I fear I am about to venture into the world of the DVT software though and maybe its capable of that. I suppose if a person spent enough on controllers and cables you could have a dual system with two controllers and switch between them but I think you approach the point of diminishing returns.?
However, it points to a possible opportunity or maybe just a future feature that advanced motor controllers will enable. ?With EV regen becoming more popular in controllers, I would not be surprised if some battery management features also start to migrate to controllers as well.?
To be true, things made in China is not my cup of tea, but in these days, unfortunately simply unavoidable !
I was a supervisor in China for several years, and know how they make things, and all of QC is not like in the West. Buy a ME1616 electromotor. Made in China, then sold in the West.
Buy yourself a german or US car. Half of the smaller parts in it are made in China by now.
Company supervisors are not in China now, because of the Made in China virus.
Who wants to spend 2-4 weeks in quarantine to go for an inspection ??
Who's checking the quality now ?
As I spin up my own commercial efforts I have been working with colleagues in CN to understand the quality dynamics and the manufacturing landscape and while I think some of these comments are in a general sense applicable, I think that the demands of growing sophistication in their domestic market, growing domestic regulatory regime, and a drive to differentiate by rising to the QC and supply chain standards of Korea, Japan, US, and Europe is pressuring a lot of CN companies to advance. ?I think now it is more a story of doing homework to understand your partners and their processes.
Now, the current chaos of the global shipping / logistics is another story! The Suez Canal incident has cost me several weeks and the knock-on effects will continue for months.? However, I believe that new, checked, LiFePO4 batteries will last my sailing life out, but the electronics is another concern. Especially in a marine environment (humid and salty). Can you provide recommendations where to setup these (rather large) electronic regulators/inverters/BMS'es in the boat ? I guess IP rating is not relevant, if not encapsuled in IP-rated boxes. If put into boxes, then there's a cooling issue...
As far from any wet bilge or dripping shaft or outdoor moisture as possible. ?In the cabin if you can. If exposed to moist air frequently try running some electric air warmer/dryers or a dehumidifier (when on shore power).?
Working hard on the ultimate solution for my own EMS/Y system conversion design.
Cheers, guys
Carsten
Hint : EMS/Y = Electric Motor Sailing Yacht ;-)
On Friday, 30 April 2021, 02:46:25 GMT+8, Jeff LaCoursiere < jeff@...> wrote:
We haven't had any bad cells imported yet, knock wood.? We *are*
doing our best to burn down our offices with our BMS experiments
though :)? Also, our latest batch was all EVE 280AH cells, the
Lishen 272AH are apparently "all gone". Another cool idea we are kicking around... we want our 48v pack
to have a 12v tap, so you can use it as your house battery as well
as your traction battery.? I'm disappointed in the available
downconverters, mostly current limited to 30-60A.? Maybe that
would be enough for your house, but it wouldn't do it for mine. So we want to try to cycle through internal banks of four cells,
very quickly (like 10khz), connecting them in turn to the 12v
tap.? We believe that this way you will be able to pull the full
1C discharge of the 16 cell pack (280A), but at 12v!? We hope to
maintain balance in discharge by cycling very fast, but the BMS
should pick up the slack.
Cheers,
Jeff LaCoursiere
s/v Angels Quest
On 4/29/21 11:34 AM, Carsten via
wrote:
Hi, Jeff
Did you experience
single/multiple cell dropouts from Lishen batteries so far ?
On Thursday, 29 April 2021, 23:22:13 GMT+8, Jeff
LaCoursiere <jeff@...>
wrote:
I
wanted to comment on 1) below - we have that same
concept in mind.? We are working on a BMS design that
will basically allow cells to be "dropped out" of
series, the output run through a boost circuit to
maintain steady voltage.? There are of course limits
to how many can drop out and we are very much at the
experimental stage here, but there is some hope :)
Jeff
LaCoursiere
s/v
Angels Quest
First
Draft of Schematic. Using Lishen 202Ah. I decided to
go with the BMS only actively controlling the charge
side of the circuit and opted for passive monitoring
on the load side. Using a victron 712 for monitoring
and hopefully can connect it to a relay to shut off
charge circuit at predetermined voltage. Guys please
tell me what I have missed.
Couple
of points.
1) Passive Load
monitoring. I have decided to go this route as i
understand that the load BMS can turn off for 2
reasons, obviously first is if whole bank drops to
a lower than 20%SOC and secondly if single cells
fail. From my perspective if I have a single cell
failure I would rather still be able to use the
other 15 cells than have no power. If I let my
bank drop to below SOC of 20% that's?on me.
2) Want to keep house bank
separate?for now, mainly as if I have to shut off
my 48v bank for low SOC I don't want to have to
worry about all my electronics being offline.
3) I want a separate?relay
to shut off charge current so that I can set this
manually. When I come back from a sail i want to
be able to top bank up to about a 70% SOC for
storage. Then on the day I want to sail I can top
it off o 90%
--
Jeff LaCoursiere
StratusTalk, Inc.
703 496 4990 x108
815 546 6599 cell
--
Jeff LaCoursiere
s/v Angels Quest
St Thomas USVI
--
![]() | Jeff LaCoursiere
STRATUSTALK, INC. / CTO
| Phone: | +1
703.496.4990 x108 | | Mobile: | +1
815.546.6599 | | Email: | jeff@...
| | Website: | | | Address: | One
Freedom Square
13th Floor
Reston, VA 20190 |
| | ? ? ? |
--
Jeff LaCoursiere
s/v Angels Quest
St Thomas USVI
|
Above 50v there are safety considerations that most DIY folks aren't
ready or willing to entertain...? I think even some regulations?
Anyone know more about that?
Cheers,
Jeff LaCoursiere
s/v Angels Quest
On 4/30/21 1:42 PM, Ryan Sweet wrote:
The other thing about 48v vs 96v is really why not
just run at 96v the whole time. Basically if you are making it
possible then all the rest of the system has to be specd to 96v
and I don’t see the reason to not keep it that way??
On Apr 30, 2021, at 11:12, Ryan Sweet
via groups.io <ryan@...> wrote:
?
Another
thing, how about making the motor wattage output
adjustable, so it is possible to use eg. 96V for a
burst mode ? Many 48V motors can be powered by 96V
(or higher).
I assume
that the wiring can handle that. Making two sets
of banks 48V, to be serial connected to 96V.
The
short "event" should of course be managed by the
BMS/power management system.
This is interesting and something Ive wondered about
but from what I’ve been able to discern it requires
dynamically reprogramming the motor controller. ?You could
imagine a switching setup that let you have 48v traction
banks in parallel but then to change them to series. ?I
wasn’t able to figure out a way to use the Seven Gen4 to
do this kind of thing, at least from reading the manual.
?I fear I am about to venture into the world of the DVT
software though and maybe its capable of that. I suppose
if a person spent enough on controllers and cables you
could have a dual system with two controllers and switch
between them but I think you approach the point of
diminishing returns.?
However, it points to a possible opportunity or maybe
just a future feature that advanced motor controllers will
enable. ?With EV regen becoming more popular in
controllers, I would not be surprised if some battery
management features also start to migrate to controllers
as well.?
To be
true, things made in China is not my cup of tea,
but in these days, unfortunately simply
unavoidable !
I was a
supervisor in China for several years, and know
how they make things, and all of QC is not like in
the West.
Buy a
ME1616 electromotor. Made in China, then sold in
the West.
Buy
yourself a german or US car. Half of the smaller
parts in it are made in China by now.
Company
supervisors are not in China now, because of the
Made in China virus.
Who wants
to spend 2-4 weeks in quarantine to go for an
inspection ??
Who's
checking the quality now ?
As I spin up my own commercial efforts I have been
working with colleagues in CN to understand the quality
dynamics and the manufacturing landscape and while I think
some of these comments are in a general sense applicable,
I think that the demands of growing sophistication in
their domestic market, growing domestic regulatory regime,
and a drive to differentiate by rising to the QC and
supply chain standards of Korea, Japan, US, and Europe is
pressuring a lot of CN companies to advance. ?I think now
it is more a story of doing homework to understand your
partners and their processes.
Now, the current chaos of the global shipping /
logistics is another story! The Suez Canal incident has
cost me several weeks and the knock-on effects will
continue for months.?
However,
I believe that new, checked, LiFePO4 batteries
will last my sailing life out, but the electronics
is another concern.
Especially
in a marine environment (humid and salty).
Can you
provide recommendations where to setup these
(rather large) electronic
regulators/inverters/BMS'es in the boat ?
I guess
IP rating is not relevant, if not encapsuled in
IP-rated boxes.
If put
into boxes, then there's a cooling issue...
As far from any wet bilge or dripping shaft or outdoor
moisture as possible. ?In the cabin if you can. If exposed
to moist air frequently try running some electric air
warmer/dryers or a dehumidifier (when on shore power).?
Working
hard on the ultimate solution for my own EMS/Y
system conversion design.
Cheers,
guys
Carsten
Hint :
EMS/Y = Electric Motor Sailing Yacht ;-)
On Friday, 30 April 2021, 02:46:25
GMT+8, Jeff LaCoursiere < jeff@...>
wrote:
We haven't had any bad cells
imported yet, knock wood.? We *are* doing
our best to burn down our offices with our
BMS experiments though :)? Also, our latest
batch was all EVE 280AH cells, the Lishen
272AH are apparently "all gone".
Another cool idea we are
kicking around... we want our 48v pack to
have a 12v tap, so you can use it as your
house battery as well as your traction
battery.? I'm disappointed in the
available downconverters, mostly current
limited to 30-60A.? Maybe that would be
enough for your house, but it wouldn't do
it for mine.
So we want to try to cycle
through internal banks of four cells, very
quickly (like 10khz), connecting them in
turn to the 12v tap.? We believe that this
way you will be able to pull the full 1C
discharge of the 16 cell pack (280A), but
at 12v!? We hope to maintain balance in
discharge by cycling very fast, but the
BMS should pick up the slack.
Cheers,
Jeff LaCoursiere
s/v Angels Quest
On
4/29/21 11:34 AM, Carsten via
wrote:
Hi, Jeff
Did you experience
single/multiple cell dropouts from
Lishen batteries so far ?
On Thursday, 29 April
2021, 23:22:13 GMT+8, Jeff LaCoursiere
<jeff@...>
wrote:
I
wanted to comment on 1) below -
we have that same concept in
mind.? We are working on a BMS
design that will basically allow
cells to be "dropped out" of
series, the output run through a
boost circuit to maintain steady
voltage.? There are of course
limits to how many can drop out
and we are very much at the
experimental stage here, but
there is some hope :)
Jeff
LaCoursiere
s/v
Angels Quest
First Draft of
Schematic. Using Lishen 202Ah. I
decided to go with the BMS only
actively controlling the charge
side of the circuit and opted
for passive monitoring on the
load side. Using a victron 712
for monitoring and hopefully can
connect it to a relay to shut
off charge circuit at
predetermined voltage. Guys
please tell me what I have
missed.
Couple of
points.
1) Passive Load
monitoring. I have decided
to go this route as i
understand that the load BMS
can turn off for 2 reasons,
obviously first is if whole
bank drops to a lower than
20%SOC and secondly if
single cells fail. From my
perspective if I have a
single cell failure I would
rather still be able to use
the other 15 cells than have
no power. If I let my bank
drop to below SOC of 20%
that's?on me.
2) Want to keep
house bank separate?for now,
mainly as if I have to shut
off my 48v bank for low SOC
I don't want to have to
worry about all my
electronics being offline.
3) I want a
separate?relay to shut off
charge current so that I can
set this manually. When I
come back from a sail i want
to be able to top bank up to
about a 70% SOC for storage.
Then on the day I want to
sail I can top it off o 90%
--
Jeff LaCoursiere
StratusTalk, Inc.
703 496 4990 x108
815 546 6599 cell
--
Jeff LaCoursiere
s/v Angels Quest
St Thomas USVI
--
![]() |
Jeff
LaCoursiere
STRATUSTALK, INC. / CTO
| Phone: |
+1 703.496.4990
x108 |
| Mobile: |
+1 815.546.6599 |
| Email: |
jeff@...
|
| Website: |
|
| Address: |
One Freedom
Square
13th Floor
Reston, VA 20190 |
|
| ? ? ? |
--
Jeff LaCoursiere
s/v Angels Quest
St Thomas USVI
--
| |
Jeff LaCoursiere
STRATUSTALK, INC. / CTO
| Phone: |
+1
703.496.4990 x108 |
| Mobile: |
+1
815.546.6599 |
| Email: |
jeff@...
|
| Website: |
|
| Address: |
One
Freedom Square
13th Floor
Reston, VA 20190 |
|
| ? ? ? |
-- Jeff LaCoursiere s/v Angels Quest St Thomas USVI
|
I guess that’s my point is if the system is capable of 96v its a different thing and should be treated as such. ?IIUC, Morris like the me1515 etc are most efficient at the higher end of their voltage range. I think the reason most of us want to keep things at 48v is that the simplicity of the system and the cost of the batteries makes it worth the efficiency trade off and lower max power.?
toggle quoted message
Show quoted text
On Apr 30, 2021, at 11:46, Jeff LaCoursiere <jeff@...> wrote:
?
Above 50v there are safety considerations that most DIY folks aren't
ready or willing to entertain...? I think even some regulations?
Anyone know more about that?
Cheers,
Jeff LaCoursiere
s/v Angels Quest
On 4/30/21 1:42 PM, Ryan Sweet wrote:
The other thing about 48v vs 96v is really why not
just run at 96v the whole time. Basically if you are making it
possible then all the rest of the system has to be specd to 96v
and I don’t see the reason to not keep it that way??
On Apr 30, 2021, at 11:12, Ryan Sweet
via groups.io <ryan@...> wrote:
?
Another
thing, how about making the motor wattage output
adjustable, so it is possible to use eg. 96V for a
burst mode ? Many 48V motors can be powered by 96V
(or higher).
I assume
that the wiring can handle that. Making two sets
of banks 48V, to be serial connected to 96V.
The
short "event" should of course be managed by the
BMS/power management system.
This is interesting and something Ive wondered about
but from what I’ve been able to discern it requires
dynamically reprogramming the motor controller. ?You could
imagine a switching setup that let you have 48v traction
banks in parallel but then to change them to series. ?I
wasn’t able to figure out a way to use the Seven Gen4 to
do this kind of thing, at least from reading the manual.
?I fear I am about to venture into the world of the DVT
software though and maybe its capable of that. I suppose
if a person spent enough on controllers and cables you
could have a dual system with two controllers and switch
between them but I think you approach the point of
diminishing returns.?
However, it points to a possible opportunity or maybe
just a future feature that advanced motor controllers will
enable. ?With EV regen becoming more popular in
controllers, I would not be surprised if some battery
management features also start to migrate to controllers
as well.?
To be
true, things made in China is not my cup of tea,
but in these days, unfortunately simply
unavoidable !
I was a
supervisor in China for several years, and know
how they make things, and all of QC is not like in
the West.
Buy a
ME1616 electromotor. Made in China, then sold in
the West.
Buy
yourself a german or US car. Half of the smaller
parts in it are made in China by now.
Company
supervisors are not in China now, because of the
Made in China virus.
Who wants
to spend 2-4 weeks in quarantine to go for an
inspection ??
Who's
checking the quality now ?
As I spin up my own commercial efforts I have been
working with colleagues in CN to understand the quality
dynamics and the manufacturing landscape and while I think
some of these comments are in a general sense applicable,
I think that the demands of growing sophistication in
their domestic market, growing domestic regulatory regime,
and a drive to differentiate by rising to the QC and
supply chain standards of Korea, Japan, US, and Europe is
pressuring a lot of CN companies to advance. ?I think now
it is more a story of doing homework to understand your
partners and their processes.
Now, the current chaos of the global shipping /
logistics is another story! The Suez Canal incident has
cost me several weeks and the knock-on effects will
continue for months.?
However,
I believe that new, checked, LiFePO4 batteries
will last my sailing life out, but the electronics
is another concern.
Especially
in a marine environment (humid and salty).
Can you
provide recommendations where to setup these
(rather large) electronic
regulators/inverters/BMS'es in the boat ?
I guess
IP rating is not relevant, if not encapsuled in
IP-rated boxes.
If put
into boxes, then there's a cooling issue...
As far from any wet bilge or dripping shaft or outdoor
moisture as possible. ?In the cabin if you can. If exposed
to moist air frequently try running some electric air
warmer/dryers or a dehumidifier (when on shore power).?
Working
hard on the ultimate solution for my own EMS/Y
system conversion design.
Cheers,
guys
Carsten
Hint :
EMS/Y = Electric Motor Sailing Yacht ;-)
On Friday, 30 April 2021, 02:46:25
GMT+8, Jeff LaCoursiere < jeff@...>
wrote:
We haven't had any bad cells
imported yet, knock wood.? We *are* doing
our best to burn down our offices with our
BMS experiments though :)? Also, our latest
batch was all EVE 280AH cells, the Lishen
272AH are apparently "all gone".
Another cool idea we are
kicking around... we want our 48v pack to
have a 12v tap, so you can use it as your
house battery as well as your traction
battery.? I'm disappointed in the
available downconverters, mostly current
limited to 30-60A.? Maybe that would be
enough for your house, but it wouldn't do
it for mine.
So we want to try to cycle
through internal banks of four cells, very
quickly (like 10khz), connecting them in
turn to the 12v tap.? We believe that this
way you will be able to pull the full 1C
discharge of the 16 cell pack (280A), but
at 12v!? We hope to maintain balance in
discharge by cycling very fast, but the
BMS should pick up the slack.
Cheers,
Jeff LaCoursiere
s/v Angels Quest
On
4/29/21 11:34 AM, Carsten via
wrote:
Hi, Jeff
Did you experience
single/multiple cell dropouts from
Lishen batteries so far ?
On Thursday, 29 April
2021, 23:22:13 GMT+8, Jeff LaCoursiere
<jeff@...>
wrote:
I
wanted to comment on 1) below -
we have that same concept in
mind.? We are working on a BMS
design that will basically allow
cells to be "dropped out" of
series, the output run through a
boost circuit to maintain steady
voltage.? There are of course
limits to how many can drop out
and we are very much at the
experimental stage here, but
there is some hope :)
Jeff
LaCoursiere
s/v
Angels Quest
First Draft of
Schematic. Using Lishen 202Ah. I
decided to go with the BMS only
actively controlling the charge
side of the circuit and opted
for passive monitoring on the
load side. Using a victron 712
for monitoring and hopefully can
connect it to a relay to shut
off charge circuit at
predetermined voltage. Guys
please tell me what I have
missed.
Couple of
points.
1) Passive Load
monitoring. I have decided
to go this route as i
understand that the load BMS
can turn off for 2 reasons,
obviously first is if whole
bank drops to a lower than
20%SOC and secondly if
single cells fail. From my
perspective if I have a
single cell failure I would
rather still be able to use
the other 15 cells than have
no power. If I let my bank
drop to below SOC of 20%
that's?on me.
2) Want to keep
house bank separate?for now,
mainly as if I have to shut
off my 48v bank for low SOC
I don't want to have to
worry about all my
electronics being offline.
3) I want a
separate?relay to shut off
charge current so that I can
set this manually. When I
come back from a sail i want
to be able to top bank up to
about a 70% SOC for storage.
Then on the day I want to
sail I can top it off o 90%
--
Jeff LaCoursiere
StratusTalk, Inc.
703 496 4990 x108
815 546 6599 cell
--
Jeff LaCoursiere
s/v Angels Quest
St Thomas USVI
--
![]() |
Jeff
LaCoursiere
STRATUSTALK, INC. / CTO
| Phone: |
+1 703.496.4990
x108 |
| Mobile: |
+1 815.546.6599 |
| Email: |
jeff@...
|
| Website: |
|
| Address: |
One Freedom
Square
13th Floor
Reston, VA 20190 |
|
| ? ? ? |
--
Jeff LaCoursiere
s/v Angels Quest
St Thomas USVI
--
| |
Jeff LaCoursiere
STRATUSTALK, INC. / CTO
| Phone: |
+1
703.496.4990 x108 |
| Mobile: |
+1
815.546.6599 |
| Email: |
jeff@...
|
| Website: |
|
| Address: |
One
Freedom Square
13th Floor
Reston, VA 20190 |
|
| ? ? ? |
-- Jeff LaCoursiere s/v Angels Quest St Thomas USVI
|
s/Morris/motors/
Autocorrect is giving me a heck of a time today.?
toggle quoted message
Show quoted text
On Apr 30, 2021, at 11:53, Ryan Sweet via groups.io <ryan@...> wrote:
? I guess that’s my point is if the system is capable of 96v its a different thing and should be treated as such. ?IIUC, Morris like the me1515 etc are most efficient at the higher end of their voltage range. I think the reason most of us want to keep things at 48v is that the simplicity of the system and the cost of the batteries makes it worth the efficiency trade off and lower max power.? On Apr 30, 2021, at 11:46, Jeff LaCoursiere <jeff@...> wrote:
?
Above 50v there are safety considerations that most DIY folks aren't
ready or willing to entertain...? I think even some regulations?
Anyone know more about that?
Cheers,
Jeff LaCoursiere
s/v Angels Quest
On 4/30/21 1:42 PM, Ryan Sweet wrote:
The other thing about 48v vs 96v is really why not
just run at 96v the whole time. Basically if you are making it
possible then all the rest of the system has to be specd to 96v
and I don’t see the reason to not keep it that way??
On Apr 30, 2021, at 11:12, Ryan Sweet
via groups.io <ryan@...> wrote:
?
Another
thing, how about making the motor wattage output
adjustable, so it is possible to use eg. 96V for a
burst mode ? Many 48V motors can be powered by 96V
(or higher).
I assume
that the wiring can handle that. Making two sets
of banks 48V, to be serial connected to 96V.
The
short "event" should of course be managed by the
BMS/power management system.
This is interesting and something Ive wondered about
but from what I’ve been able to discern it requires
dynamically reprogramming the motor controller. ?You could
imagine a switching setup that let you have 48v traction
banks in parallel but then to change them to series. ?I
wasn’t able to figure out a way to use the Seven Gen4 to
do this kind of thing, at least from reading the manual.
?I fear I am about to venture into the world of the DVT
software though and maybe its capable of that. I suppose
if a person spent enough on controllers and cables you
could have a dual system with two controllers and switch
between them but I think you approach the point of
diminishing returns.?
However, it points to a possible opportunity or maybe
just a future feature that advanced motor controllers will
enable. ?With EV regen becoming more popular in
controllers, I would not be surprised if some battery
management features also start to migrate to controllers
as well.?
To be
true, things made in China is not my cup of tea,
but in these days, unfortunately simply
unavoidable !
I was a
supervisor in China for several years, and know
how they make things, and all of QC is not like in
the West.
Buy a
ME1616 electromotor. Made in China, then sold in
the West.
Buy
yourself a german or US car. Half of the smaller
parts in it are made in China by now.
Company
supervisors are not in China now, because of the
Made in China virus.
Who wants
to spend 2-4 weeks in quarantine to go for an
inspection ??
Who's
checking the quality now ?
As I spin up my own commercial efforts I have been
working with colleagues in CN to understand the quality
dynamics and the manufacturing landscape and while I think
some of these comments are in a general sense applicable,
I think that the demands of growing sophistication in
their domestic market, growing domestic regulatory regime,
and a drive to differentiate by rising to the QC and
supply chain standards of Korea, Japan, US, and Europe is
pressuring a lot of CN companies to advance. ?I think now
it is more a story of doing homework to understand your
partners and their processes.
Now, the current chaos of the global shipping /
logistics is another story! The Suez Canal incident has
cost me several weeks and the knock-on effects will
continue for months.?
However,
I believe that new, checked, LiFePO4 batteries
will last my sailing life out, but the electronics
is another concern.
Especially
in a marine environment (humid and salty).
Can you
provide recommendations where to setup these
(rather large) electronic
regulators/inverters/BMS'es in the boat ?
I guess
IP rating is not relevant, if not encapsuled in
IP-rated boxes.
If put
into boxes, then there's a cooling issue...
As far from any wet bilge or dripping shaft or outdoor
moisture as possible. ?In the cabin if you can. If exposed
to moist air frequently try running some electric air
warmer/dryers or a dehumidifier (when on shore power).?
Working
hard on the ultimate solution for my own EMS/Y
system conversion design.
Cheers,
guys
Carsten
Hint :
EMS/Y = Electric Motor Sailing Yacht ;-)
On Friday, 30 April 2021, 02:46:25
GMT+8, Jeff LaCoursiere < jeff@...>
wrote:
We haven't had any bad cells
imported yet, knock wood.? We *are* doing
our best to burn down our offices with our
BMS experiments though :)? Also, our latest
batch was all EVE 280AH cells, the Lishen
272AH are apparently "all gone".
Another cool idea we are
kicking around... we want our 48v pack to
have a 12v tap, so you can use it as your
house battery as well as your traction
battery.? I'm disappointed in the
available downconverters, mostly current
limited to 30-60A.? Maybe that would be
enough for your house, but it wouldn't do
it for mine.
So we want to try to cycle
through internal banks of four cells, very
quickly (like 10khz), connecting them in
turn to the 12v tap.? We believe that this
way you will be able to pull the full 1C
discharge of the 16 cell pack (280A), but
at 12v!? We hope to maintain balance in
discharge by cycling very fast, but the
BMS should pick up the slack.
Cheers,
Jeff LaCoursiere
s/v Angels Quest
On
4/29/21 11:34 AM, Carsten via
wrote:
Hi, Jeff
Did you experience
single/multiple cell dropouts from
Lishen batteries so far ?
On Thursday, 29 April
2021, 23:22:13 GMT+8, Jeff LaCoursiere
<jeff@...>
wrote:
I
wanted to comment on 1) below -
we have that same concept in
mind.? We are working on a BMS
design that will basically allow
cells to be "dropped out" of
series, the output run through a
boost circuit to maintain steady
voltage.? There are of course
limits to how many can drop out
and we are very much at the
experimental stage here, but
there is some hope :)
Jeff
LaCoursiere
s/v
Angels Quest
First Draft of
Schematic. Using Lishen 202Ah. I
decided to go with the BMS only
actively controlling the charge
side of the circuit and opted
for passive monitoring on the
load side. Using a victron 712
for monitoring and hopefully can
connect it to a relay to shut
off charge circuit at
predetermined voltage. Guys
please tell me what I have
missed.
Couple of
points.
1) Passive Load
monitoring. I have decided
to go this route as i
understand that the load BMS
can turn off for 2 reasons,
obviously first is if whole
bank drops to a lower than
20%SOC and secondly if
single cells fail. From my
perspective if I have a
single cell failure I would
rather still be able to use
the other 15 cells than have
no power. If I let my bank
drop to below SOC of 20%
that's?on me.
2) Want to keep
house bank separate?for now,
mainly as if I have to shut
off my 48v bank for low SOC
I don't want to have to
worry about all my
electronics being offline.
3) I want a
separate?relay to shut off
charge current so that I can
set this manually. When I
come back from a sail i want
to be able to top bank up to
about a 70% SOC for storage.
Then on the day I want to
sail I can top it off o 90%
--
Jeff LaCoursiere
StratusTalk, Inc.
703 496 4990 x108
815 546 6599 cell
--
Jeff LaCoursiere
s/v Angels Quest
St Thomas USVI
--
![]() |
Jeff
LaCoursiere
STRATUSTALK, INC. / CTO
| Phone: |
+1 703.496.4990
x108 |
| Mobile: |
+1 815.546.6599 |
| Email: |
jeff@...
|
| Website: |
|
| Address: |
One Freedom
Square
13th Floor
Reston, VA 20190 |
|
| ? ? ? |
--
Jeff LaCoursiere
s/v Angels Quest
St Thomas USVI
--
| |
Jeff LaCoursiere
STRATUSTALK, INC. / CTO
| Phone: |
+1
703.496.4990 x108 |
| Mobile: |
+1
815.546.6599 |
| Email: |
jeff@...
|
| Website: |
|
| Address: |
One
Freedom Square
13th Floor
Reston, VA 20190 |
|
| ? ? ? |
-- Jeff LaCoursiere s/v Angels Quest St Thomas USVI
|
Any voltage system above 50V is very hard to get boat insurance for. Kai
toggle quoted message
Show quoted text
On 30 Apr 2021, at 19:53, Ryan Sweet <ryan@...> wrote:
? I guess that’s my point is if the system is capable of 96v its a different thing and should be treated as such. ?IIUC, Morris like the me1515 etc are most efficient at the higher end of their voltage range. I think the reason most of us want to keep things at 48v is that the simplicity of the system and the cost of the batteries makes it worth the efficiency trade off and lower max power.? On Apr 30, 2021, at 11:46, Jeff LaCoursiere <jeff@...> wrote:
?
Above 50v there are safety considerations that most DIY folks aren't
ready or willing to entertain...? I think even some regulations?
Anyone know more about that?
Cheers,
Jeff LaCoursiere
s/v Angels Quest
On 4/30/21 1:42 PM, Ryan Sweet wrote:
The other thing about 48v vs 96v is really why not
just run at 96v the whole time. Basically if you are making it
possible then all the rest of the system has to be specd to 96v
and I don’t see the reason to not keep it that way??
On Apr 30, 2021, at 11:12, Ryan Sweet
via groups.io <ryan@...> wrote:
?
Another
thing, how about making the motor wattage output
adjustable, so it is possible to use eg. 96V for a
burst mode ? Many 48V motors can be powered by 96V
(or higher).
I assume
that the wiring can handle that. Making two sets
of banks 48V, to be serial connected to 96V.
The
short "event" should of course be managed by the
BMS/power management system.
This is interesting and something Ive wondered about
but from what I’ve been able to discern it requires
dynamically reprogramming the motor controller. ?You could
imagine a switching setup that let you have 48v traction
banks in parallel but then to change them to series. ?I
wasn’t able to figure out a way to use the Seven Gen4 to
do this kind of thing, at least from reading the manual.
?I fear I am about to venture into the world of the DVT
software though and maybe its capable of that. I suppose
if a person spent enough on controllers and cables you
could have a dual system with two controllers and switch
between them but I think you approach the point of
diminishing returns.?
However, it points to a possible opportunity or maybe
just a future feature that advanced motor controllers will
enable. ?With EV regen becoming more popular in
controllers, I would not be surprised if some battery
management features also start to migrate to controllers
as well.?
To be
true, things made in China is not my cup of tea,
but in these days, unfortunately simply
unavoidable !
I was a
supervisor in China for several years, and know
how they make things, and all of QC is not like in
the West.
Buy a
ME1616 electromotor. Made in China, then sold in
the West.
Buy
yourself a german or US car. Half of the smaller
parts in it are made in China by now.
Company
supervisors are not in China now, because of the
Made in China virus.
Who wants
to spend 2-4 weeks in quarantine to go for an
inspection ??
Who's
checking the quality now ?
As I spin up my own commercial efforts I have been
working with colleagues in CN to understand the quality
dynamics and the manufacturing landscape and while I think
some of these comments are in a general sense applicable,
I think that the demands of growing sophistication in
their domestic market, growing domestic regulatory regime,
and a drive to differentiate by rising to the QC and
supply chain standards of Korea, Japan, US, and Europe is
pressuring a lot of CN companies to advance. ?I think now
it is more a story of doing homework to understand your
partners and their processes.
Now, the current chaos of the global shipping /
logistics is another story! The Suez Canal incident has
cost me several weeks and the knock-on effects will
continue for months.?
However,
I believe that new, checked, LiFePO4 batteries
will last my sailing life out, but the electronics
is another concern.
Especially
in a marine environment (humid and salty).
Can you
provide recommendations where to setup these
(rather large) electronic
regulators/inverters/BMS'es in the boat ?
I guess
IP rating is not relevant, if not encapsuled in
IP-rated boxes.
If put
into boxes, then there's a cooling issue...
As far from any wet bilge or dripping shaft or outdoor
moisture as possible. ?In the cabin if you can. If exposed
to moist air frequently try running some electric air
warmer/dryers or a dehumidifier (when on shore power).?
Working
hard on the ultimate solution for my own EMS/Y
system conversion design.
Cheers,
guys
Carsten
Hint :
EMS/Y = Electric Motor Sailing Yacht ;-)
On Friday, 30 April 2021, 02:46:25
GMT+8, Jeff LaCoursiere < jeff@...>
wrote:
We haven't had any bad cells
imported yet, knock wood.? We *are* doing
our best to burn down our offices with our
BMS experiments though :)? Also, our latest
batch was all EVE 280AH cells, the Lishen
272AH are apparently "all gone".
Another cool idea we are
kicking around... we want our 48v pack to
have a 12v tap, so you can use it as your
house battery as well as your traction
battery.? I'm disappointed in the
available downconverters, mostly current
limited to 30-60A.? Maybe that would be
enough for your house, but it wouldn't do
it for mine.
So we want to try to cycle
through internal banks of four cells, very
quickly (like 10khz), connecting them in
turn to the 12v tap.? We believe that this
way you will be able to pull the full 1C
discharge of the 16 cell pack (280A), but
at 12v!? We hope to maintain balance in
discharge by cycling very fast, but the
BMS should pick up the slack.
Cheers,
Jeff LaCoursiere
s/v Angels Quest
On
4/29/21 11:34 AM, Carsten via
wrote:
Hi, Jeff
Did you experience
single/multiple cell dropouts from
Lishen batteries so far ?
On Thursday, 29 April
2021, 23:22:13 GMT+8, Jeff LaCoursiere
<jeff@...>
wrote:
I
wanted to comment on 1) below -
we have that same concept in
mind.? We are working on a BMS
design that will basically allow
cells to be "dropped out" of
series, the output run through a
boost circuit to maintain steady
voltage.? There are of course
limits to how many can drop out
and we are very much at the
experimental stage here, but
there is some hope :)
Jeff
LaCoursiere
s/v
Angels Quest
First Draft of
Schematic. Using Lishen 202Ah. I
decided to go with the BMS only
actively controlling the charge
side of the circuit and opted
for passive monitoring on the
load side. Using a victron 712
for monitoring and hopefully can
connect it to a relay to shut
off charge circuit at
predetermined voltage. Guys
please tell me what I have
missed.
Couple of
points.
1) Passive Load
monitoring. I have decided
to go this route as i
understand that the load BMS
can turn off for 2 reasons,
obviously first is if whole
bank drops to a lower than
20%SOC and secondly if
single cells fail. From my
perspective if I have a
single cell failure I would
rather still be able to use
the other 15 cells than have
no power. If I let my bank
drop to below SOC of 20%
that's?on me.
2) Want to keep
house bank separate?for now,
mainly as if I have to shut
off my 48v bank for low SOC
I don't want to have to
worry about all my
electronics being offline.
3) I want a
separate?relay to shut off
charge current so that I can
set this manually. When I
come back from a sail i want
to be able to top bank up to
about a 70% SOC for storage.
Then on the day I want to
sail I can top it off o 90%
--
Jeff LaCoursiere
StratusTalk, Inc.
703 496 4990 x108
815 546 6599 cell
--
Jeff LaCoursiere
s/v Angels Quest
St Thomas USVI
--
![]() |
Jeff
LaCoursiere
STRATUSTALK, INC. / CTO
| Phone: |
+1 703.496.4990
x108 |
| Mobile: |
+1 815.546.6599 |
| Email: |
jeff@...
|
| Website: |
|
| Address: |
One Freedom
Square
13th Floor
Reston, VA 20190 |
|
| ? ? ? |
--
Jeff LaCoursiere
s/v Angels Quest
St Thomas USVI
--
| |
Jeff LaCoursiere
STRATUSTALK, INC. / CTO
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+1
703.496.4990 x108 |
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+1
815.546.6599 |
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jeff@...
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One
Freedom Square
13th Floor
Reston, VA 20190 |
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-- Jeff LaCoursiere s/v Angels Quest St Thomas USVI
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?? I did wonder but haven’t tried to figure out if you could run the DCDC converters in parallel, do you know? ? For sure you can parallel modules/converters that are designed to allow that. As example: Vicor DCDC modules used in Vicor Megapac power supply racks.? The Megapac units provide a 200-250vDC rail voltage to all modules in the rack. ?Individual module outputs can be connected in series or in parallel, with certain restrictions or techniques.? That’s an extreme example, and only has a single DCDC input source, but fundamentally, one can have a design that allows paralleling DCDC outputs with distinctly different sources.? The challenge is to ensure current sharing of the DCDC units.? The Vicor example I mentioned will automatically current share if subsequent DCDC put into Slave mode with one unit set as Master.? But you can also passively achieve current sharing if all the DCDC outputs have very close load curves.? Certainly you want these things to be current limiting (i.e. CV/CI), current protected, voltage protected, short protected, thermally protected, etc. ? ?
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Cycling through 4x series-connected 12v batteries will require a high current, isolated multiplexing circuit. The loss generated by the switching components will likely be as great a loss as a buck converter from 48v to 12v. And, the electrical noise introduced onto the DC bus will need to be handled because it will be pretty extreme since overlapping during the switch won't work due to the need to be isolated (so as not to get 24v when the circuit expected 12v). I recommend multiple smaller (~50a) buck conveters because they run nicely in parallel and can give you some redundancy. I run 4x 50a 96v to 12v converters on a main 12vdc bus and 4x 15a 96v to 12v converters on 4x isolated special purpose 12vdc busses.
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cpcanoesailor
Randy Cain