House systems - separate or together with drive system?
I am at the beginning of a conversion for a 32¡¯ ketch, and I have the 10kw thunderstruck kit, charger, reduction, and battery bank all working on my bench under artificial load. She will be at a dock soon where I can pull the diesel and begin refitting with the EV drive.
The boat has an existing house system with four 6v golf cart batteries in 2p2s for both the 12v house loads and the starting motor, along with two 50w solar panels and a charge controller. During the summer in the Pacific NW the solar keeps up with the house loads at anchor all summer, she is usually at a dock plugged in for much of the winter.
I originally intended to leave all the existing 12v system in place, and keep the 48v ev system separate, but I¡¯m realizing that once the old motor comes out, it¡¯s really prime time to simplify as many things as possible, so I¡¯m wondering about the necessary equipment and pros/cons of running the house load off of the same battery bank as the EV (right now I am working the EV with 4x 12v 200ah AGM in 4s).
What becomes complicated or inefficient about running them together (with a 48v to 12v step down) vs having separate systems?
I halfway thought that I would try leaving the existing house system as-is, adding the EV with the AGM bank separately, and if it is all working well, then switching the EV drove to a m bank of lifepo4 and rewiring the AGM bank in 4p at 12v, replacing the older system which is nearing end of life in the next few years anyway. But I also am drawn to the simplicity of only having one set of batteries to worry about for all loads.
What are the practical considerations that you guys have encountered for each scenario?
My boat will mostly be used for crushing near shore, likely with power though most winters, and at anchor or underway in summers.
|
Re: Lake Test - 13' plywood runabout with Torqeedo 4R, and 50Ah eBike battery bank
Jerry, Unfortunately, the wiring on the batteries is small.? Probably only good for 30A.? I currently have a 30Amp breaker between the battery and the motor to prevent overheating the wires coming out of the battery.
I was hopeful I would get a chance to test cranking up the motor at the dock when the boat was back on the trailer - but a barge was taking up two of the 3 lanes, and a line was starting to form, so I didn't have a chance to test what power level (and how long) would trip the breaker.
If the Chinese motor will put out 2kw worth of power, you should be fine.? ?I have tested a Catalina 22 with a Torqeedo 2T (2000W max).? At 1000-1200W, the C22 went about 4mph.? The C22 is a MUCH tougher shape to push than your catamaran, and MUCH heavier.? As always, if you want to go much faster, you'll need a LOT more power.
Dramatically increasing the power will get you a little more speed - but it's not sustainable.? Even if the battery wiring could handle 2500W (max rating of the battery - probably based on the wiring...) - it would exhaust the battery in under an hour.? ?I want at least 2-3 hours of cruising time for a power boat to be considered practical.? At 500-600W, I should be able to cruise at 3.5-4mph for 3-4 hours on a 50Ah battery.? At 500W for 3 hours, I'll have a nice cruise without overly exhausting the battery.
Do you have a place to mount a single motor (between the two pontoons?) You may also be challenged to find 24V eBike motors.
For my boat - the sweet spot for cruising seems to be around 600W - hitting around 4mph.? At that power level, a single 50Ah, 48V eBike battery should give me around 2 hours of cruising.? ?And then, if "something bad happens", I have the 20Ah backup battery that should give me around an hour of "get home" cruising.
On Wednesday, June 24, 2020, 10:38:16 PM CDT, shredderf16 <shredderf16@...> wrote:
John,
Please cranky uppy to 4k watts and let us know results. I got a 2.3 kw chinese motor and building 12' catamaran dinghy. I think I can get by with the one motor but may need two. Thinking bike batteries like you did.
Jerry Barth
On June 24, 2020, at 3:45 PM, "john via groups.io" <oak_box@...> wrote: On Monday, 6/22/20, I conducted my first on the water Lake trial with my electric conversion, "Mischief". Mischief is a home built plywood runabout, currently powered with a Torqeedo 4R outboard.? Specs are below:
LOA:? 13' 4" (without motor) Beam:? 5'9" Weight:? about 300-400# Draft:? approximately 6-7", with motor up. Theoretical Hull Speed:? 4.9mph
Motor:? Torqeedo 4R electric outboard (with remote steering) ? ? 48V, max 4000W input
Battery: ? Main battery bank:? 48V 50Ah eBike battery system from BTR (ordered on Amazon) (approx $900) ? Backup / get home battery:? ?48V 20Ah eBike Battery system from BTR? (under $500)
Both battery systems were bench tested.? For each test, the battery was fully charged, and then connected to sets of #9006 12V halogen light bulbs (4 bulbs in series gives a 48V load at about 4A).? Time and voltage were recorded periodically until the battery BMS shut down the voltage output from the battery.? Tests were conducted with 4, 8, and 16 bulbs (max was 4 parallel sets of 4 bulbs, approximately 800-900W).? I have the data on these tests, if anyone is interested.
At the lake!! First test was a static test of running the boat at the boat ramp (the motor needs to be in the water when running).? The motor was run at 1000W, and ran for approximately 45 min before the BMS dropped out, on the 20Ah battery.? The BMS dropped out at about 48V.? ?(The BMS on the 50Ah battery drops out at around 40V.)
The first "on the water" test lasted for approximately an hour, and used approximately 30-50% of the capacity of the 50Ah battery bank.
Performance of the boat consistently met expectations.? Handling was great.? As long as you're ok with a walking speed cruise - the boat performed very well.
?Volts Amps Watts MPH ?58.2? ? 5.15 300 ????????3 ?57.0 6.5 ????????370 ????????3.5 ?56.8 8.80 500 ???????? 3.9 ?57.7 10.4 600 ????????4 ?56.0 15.71 880 ????????4.9 ?57 ????????17.54 1000 5 ?56 ????????26.79 1500 5.7
I've attached a couple of pictures of the boat.? Please let me know if they don't come across.
If anyone would like more details, feel free to contact me.
John
|
Re: Lake Test - 13' plywood runabout with Torqeedo 4R, and 50Ah eBike battery bank
John,
Please cranky uppy to 4k watts and let us know results. I got a 2.3 kw chinese motor and building 12' catamaran dinghy. I think I can get by with the one motor but may need two. Thinking bike batteries like you did.
Jerry Barth
On June 24, 2020, at 3:45 PM, "john via groups.io" <oak_box@...> wrote: On Monday, 6/22/20, I conducted my first on the water Lake trial with my electric conversion, "Mischief". Mischief is a home built plywood runabout, currently powered with a Torqeedo 4R outboard.? Specs are below:
LOA:? 13' 4" (without motor) Beam:? 5'9" Weight:? about 300-400# Draft:? approximately 6-7", with motor up. Theoretical Hull Speed:? 4.9mph
Motor:? Torqeedo 4R electric outboard (with remote steering) ? ? 48V, max 4000W input
Battery: ? Main battery bank:? 48V 50Ah eBike battery system from BTR (ordered on Amazon) (approx $900) ? Backup / get home battery:? ?48V 20Ah eBike Battery system from BTR? (under $500)
Both battery systems were bench tested.? For each test, the battery was fully charged, and then connected to sets of #9006 12V halogen light bulbs (4 bulbs in series gives a 48V load at about 4A).? Time and voltage were recorded periodically until the battery BMS shut down the voltage output from the battery.? Tests were conducted with 4, 8, and 16 bulbs (max was 4 parallel sets of 4 bulbs, approximately 800-900W).? I have the data on these tests, if anyone is interested.
At the lake!! First test was a static test of running the boat at the boat ramp (the motor needs to be in the water when running).? The motor was run at 1000W, and ran for approximately 45 min before the BMS dropped out, on the 20Ah battery.? The BMS dropped out at about 48V.? ?(The BMS on the 50Ah battery drops out at around 40V.)
The first "on the water" test lasted for approximately an hour, and used approximately 30-50% of the capacity of the 50Ah battery bank.
Performance of the boat consistently met expectations.? Handling was great.? As long as you're ok with a walking speed cruise - the boat performed very well.
?Volts Amps Watts MPH ?58.2? ? 5.15 300 ????????3 ?57.0 6.5 ????????370 ????????3.5 ?56.8 8.80 500 ???????? 3.9 ?57.7 10.4 600 ????????4 ?56.0 15.71 880 ????????4.9 ?57 ????????17.54 1000 5 ?56 ????????26.79 1500 5.7
I've attached a couple of pictures of the boat.? Please let me know if they don't come across.
If anyone would like more details, feel free to contact me.
John
|
Lake Test - 13' plywood runabout with Torqeedo 4R, and 50Ah eBike battery bank
On Monday, 6/22/20, I conducted my first on the water Lake trial with my electric conversion, "Mischief". Mischief is a home built plywood runabout, currently powered with a Torqeedo 4R outboard.? Specs are below:
LOA:? 13' 4" (without motor) Beam:? 5'9" Weight:? about 300-400# Draft:? approximately 6-7", with motor up. Theoretical Hull Speed:? 4.9mph
Motor:? Torqeedo 4R electric outboard (with remote steering) ? ? 48V, max 4000W input
Battery: ? Main battery bank:? 48V 50Ah eBike battery system from BTR (ordered on Amazon) (approx $900) ? Backup / get home battery:? ?48V 20Ah eBike Battery system from BTR? (under $500)
Both battery systems were bench tested.? For each test, the battery was fully charged, and then connected to sets of #9006 12V halogen light bulbs (4 bulbs in series gives a 48V load at about 4A).? Time and voltage were recorded periodically until the battery BMS shut down the voltage output from the battery.? Tests were conducted with 4, 8, and 16 bulbs (max was 4 parallel sets of 4 bulbs, approximately 800-900W).? I have the data on these tests, if anyone is interested.
At the lake!! First test was a static test of running the boat at the boat ramp (the motor needs to be in the water when running).? The motor was run at 1000W, and ran for approximately 45 min before the BMS dropped out, on the 20Ah battery.? The BMS dropped out at about 48V.? ?(The BMS on the 50Ah battery drops out at around 40V.)
The first "on the water" test lasted for approximately an hour, and used approximately 30-50% of the capacity of the 50Ah battery bank.
Performance of the boat consistently met expectations.? Handling was great.? As long as you're ok with a walking speed cruise - the boat performed very well.
?Volts Amps Watts MPH ?58.2? ? 5.15 300 ????????3 ?57.0 6.5 ????????370 ????????3.5 ?56.8 8.80 500 ???????? 3.9 ?57.7 10.4 600 ????????4 ?56.0 15.71 880 ????????4.9 ?57 ????????17.54 1000 5 ?56 ????????26.79 1500 5.7
I've attached a couple of pictures of the boat.? Please let me know if they don't come across.
If anyone would like more details, feel free to contact me.
John
|
Re: Need some mechanical help in UK or Oz to prepare for electric - anyone recommended?
Not sure where you¡¯ll find a split cogged pulley. Not sure what you mean by ¡°pack?¡± The Thunderstruck motor mount will not work for you, as is. But you may be able to remove the stub shaft and coupling so that it could work? Or You¡¯ll have to make an aluminum plate on which to mount the motor - I found one last year already machined for most motors. You can use a jig saw to shape a 1/2¡± plate. You¡¯ll need a method to tighten the belt.?
|
Re: Need some mechanical help in UK or Oz to prepare for electric - anyone recommended?
Hi Reuben, Thank you! That helps a lot.
I was trying to get away from machining a keyway by bolting onto the coupling - the keyway would be much more costly and time consuming.?
I totally agree with the multi-belt idea too. If I can have a split pulley, then maintenance of it is easy and having a few spare belts makes the installation considerably more robust. If I can¡¯t split the pulley, it¡¯s probably ok as I don¡¯t expect it to go too wrong regularly (eek!).
Could you find the companies who sell the packs? Thunderstruck do so for reduction ¡°box¡± but don¡¯t assume it¡¯s a parallel Installation, instead it¡¯s for direct connection to the prop shaft it seems.
Thanks
toggle quoted message
Show quoted text
On 12 Jun 2020, at 12:10 am, Reuben Trane via groups.io <rjtrane@...> wrote:
? A 1¡± clogged belt is OK for 10 kW. That¡¯s what I have. Perhaps you¡¯ll need the shaft pulley aft of the coupling - you¡¯ll need to pull the shafts and have them machined for the pulley key way. I¡¯d buy several extra belts and store them in place around the shaft so if you need to replace a belt, you won¡¯t need to undo the coupling.?
ive seen some companies that sell an aftermarket add on for a parallel system. Includes everything you need.?
|
Re: AC vs DC gensets, how many?
There¡¯s no free lunch. If the motor is generating 5kW then you¡¯ll be using 5kW if diesel plus at Keats 10% for losses. that said, it¡¯s more efficient than adding a stand alone generator?
making the same 5kW ??
?
|
Re: Need some mechanical help in UK or Oz to prepare for electric - anyone recommended?
A 1¡± clogged belt is OK for 10 kW. That¡¯s what I have. Perhaps you¡¯ll need the shaft pulley aft of the coupling - you¡¯ll need to pull the shafts and have them machined for the pulley key way. I¡¯d buy several extra belts and store them in place around the shaft so if you need to replace a belt, you won¡¯t need to undo the coupling.?
ive seen some companies that sell an aftermarket add on for a parallel system. Includes everything you need.?
|
Need some mechanical help in UK or Oz to prepare for electric - anyone recommended?
We are planning the parallel hybrid on our powercat.
At the moment, the thought is to attach a plate to the existing shaft-gearbox coupler (which I assume is there for some flexibility, like a more modern flexible coupling?) - see photo below at centre.
It has 4 bolts, and I think it could take a machined circular disc with width enough for a serpentine belt (to take the power of 10kW or so!) and cutout centre for the prop shaft.
So some questions for the world :)...
- can we add in the plate and use longer bolts against that coupler?
- how big a serpentine do we need to run 10kW through it?
- if we bolt onto the shaft side of the coupler, where there is space, can we sit the electric motor on the hull rather than the engine, since the coupler should have taken all the engine movement out of the equation?
- can we use a split plate with 2 bolts each instead of a single? If so, maintenance could be a lot easier!
- would steel be right for the plate?
Given all that ¡°thinking¡±, I need some mechanical genius to tell me I¡¯m wrong and work with me on making it right - does anyone know someone like that in the Solent area (boat) or Australia (us right now)?
Rob
|
Re: AC vs DC gensets, how many?
Thanks Steve. I have watched the YT of Bruce Wilson on his Lagoon 410 too! It is great to see people out there doing it.
|
Re: AC vs DC gensets, how many?
Well, there¡¯s no actual system yet except in my head.
I would certainly like the ability for the motor to act as a generator when running under diesel.
i understand though that it depends on the type of motor - AC, BLDC, BDC? Still learning...
Question - if we did have a 10kW continuous motor Acting as a generator, probably using a 2:1 or 3:1 reduction (or opposite!) to keep the same prop as diesel, how much of the diesel power will I lose to the New ¡°alternator¡± and how much of that will actually get back to the batteries? ?For example, if at half max rpms the diesel is putting out 20 kW (in hp :), would I lose half the 10kW =5kW into the electric-now-generating? So only 15kW getting to prop (ignoring loss for stern gland)? ?If so, how much of the 5kW would actually recharge the batteries - ie. would a 90% efficient motor recharge at 90% to?
We will definitely be running all DC if possible.
|
I just purchased a $24 contactor from Amazon that could work for you:
WINJUN 4Pin Auto Starter Relay 12V DC 500 Amp Vehicle SPST Contactor?
I¡¯ll use it on my charge bus with max current of about 100A. I use the Tyco one for my load bus which can use over 400A. OK to use 12v to close contactor and have 48v connected to the high amp connections.?
the Tyco uses 6A of 12v to close the contact. If you have an inverter in the bus, you¡¯ll need to rig a ¡°slow start.¡±
|
One other question I had - and hope one of the experts can answer this:
I don't see a max voltage rating on the contacts for any of the contactors.? Only the voltage of the coil, and the amperage limit of the contactors.
Is it safe to use a 12V contactor (low switching voltage going to the coil) to switch a 48V battery bank?
Ryan, Thank you for the second contactor suggestion (from Amazon) - more affordable, but more importantly - that one appears to be intended for DC, whereas the original Thunderstruck suggestion was for AC.? If it's electromechancial, might work??? I'm not an expert there.? ?I know it wouldn't work to use an AC solid state relay in a DC circuit.
As someone else mentioned, the golf cart contactors are frequently used with the flyback diode on the coil, which is probably important at these voltage levels.? ?I'm not sure about the "precharge resistor".? I agree with the implementation if you're switching the motor on and off directly.? ?However, I'm assuming that for a 48V system with a 500 ohm resistor, you're adding about a 100mA CONSTANT load this is always there.? Since I'm using the contactor to switch on and off the battery bank, I don't want that load when the contactor is turned off.? ?And, since the controller should be powered down when the battery bank is switched on/off - the resistor shouldn't be needed (there should be no load when the contactor is switched on or off).
On Tuesday, June 9, 2020, 09:02:59 AM CDT, Ryan G via groups.io <ryanwestbrookcary1@...> wrote:
Here's another more affordable option than thunderstrucks offering: Looks like yours is still lighter on the coffer though.? I know that there are some that fortunate enough for see "money as no object", and am happy for them. But personally, I spend a chunk of my time looking for the ways I can do what I am trying to do affordably, and using a $40 or $50 cart/industrial relay instead of a specialty $125 relay that does the same job is a perfect example of the kind of though that makes these projects even possible on my budget.?
On Tue, Jun 9, 2020 at 9:37 AM, ryanwestbrookcary1@... <ryanwestbrookcary1@...> wrote: If you are using a 48v nominal bank with a max amp draw of 50a, but the golf cart contactor should work just fine as the motor that the golf cart relay was designed to potentially energize has a significantly higher amp draw. I looked up the ezgo cart motors yesterday, and the smallest 48v motor they sell is 4hp, so 4hpx750w=3000w 3000w/48v=62.5a They use the same relay on the 8.5hp motor aswell, so you should have a significant safety margin as far as what it was designed to handle.? That you intend to use it far below its rated capacity generally means you can expect an extended service life of the part, another advantage.? And in closing I will say that I feel as you are doing the right thing thinking outside of the box. I usually build all my own stuff out of components rather than buying sets, often using parts that meet the specs I need that were manufactured for another application. This is what allows me to afford my projects, because everyone here will attest that none of this stuff is inexpensive to begin with, and getting others to do the engineering or sell you a "specialty" part can make the war chest dry with a quickness.?
Hope this helps! On Tue, Jun 9, 2020 at 8:43 AM, Bob Jennings <heatnh@...> wrote: John, can't comment on whether that contactor is correct for your application. This is the contactor thst came with my 10KW setup. Perhaps you could cross reference it.
I'd like to put a contactor or solid state relay between my battery and motor so that I can use a simple toggle switch to turn on/off the battery.? ?Longer term, the bms could disable the battery, or I could even select between battery banks.
But for now, starting simple with an electrically controlled switch for the battery.
I'm using a 48V system. Typical max operating current may be as low as 20A, but could get spikes up to 50A.
I've looked at DC solid state relays.? And even found some rated up to 48V.? The problem is that when you read the fine print and reviews - even the 100A? SSR's are not rated for anywhere near that amount of current for constant usage.? ?(arrrgh!!)
I then started looking at "contactors", and eventually ended up looking at 48V golf cart solenoids. I've always thought of a "solenoid" in this case as being a really big relay.? It looks like the 48V golf cart solenoids should work for this application:
(Note - I'm on fresh water, and the solenoid would be in a plastic case - so I'm not worried about corrosion.)
Is that what I'm looking for, or do I need something that's more "heavy duty"? I saw references to using a flyback diode on the control contacts - and that seemed like a good idea.? Anything else I need to know?
Thanks! John
|
Don't get me wrong, if someone lacks sufficient knowledge to safely and effectively engineer and build their own system, they should absolutely go with a turn-key offering and pay someone else the big bucks necessary or not mess with it at all.... But this from is really representative of a niche market of, from what I can tell, mostly passionate diy-ers that have an interest in understanding what they are trying to build or re-fit. Some here look for advice on turn-key systems, but many seem to be more interested in the technical aspect of how to make it work, and come here to ask those with the knowledge and experience for advise, a wise move if they themself lack it. Once someone has a basic understanding of electrical theory, it is not hard to figure out what components will work together. And sometimes, in researching alternative options, great innovations are made (keep in mind that the guys at thunderstrck and similar companies really just figured this same stuff out themselves and sometimes we find ways to improve the kits they offer by just swapping one of their components)
Even the Curtis controllers they offer can be bought at around half the price they want on places like eBay and Amazon.?
All that said, I just hate how the industry leaders like to make everything a "rich mans sport" ?I am reminded of the gear reviews and suggestions in rags like f&s, to see what they recommend one could get the impression that you gotta have a six figure salary to even consider deer hunting! But au contraire, I have put much venison on the table with a $70 Moisan nagant wearing gi surp bdus?
For those on a budget, a little interest and education can potentially make something possible that otherwise would not have been due to finance. It's not a coincidence that people like Edison and tesla came from meager beginnings... if they had been better off, they may never have had the ambition to develop the ideas they had into actual things.?
Like you say, just my 2 cents
On Tue, Jun 9, 2020 at 9:37 AM, ryanwestbrookcary1@... <ryanwestbrookcary1@...> wrote: If you are using a 48v nominal bank with a max amp draw of 50a, but the golf cart contactor should work just fine as the motor that the golf cart relay was designed to potentially energize has a significantly higher amp draw. I looked up the ezgo cart motors yesterday, and the smallest 48v motor they sell is 4hp, so 4hpx750w=3000w 3000w/48v=62.5a They use the same relay on the 8.5hp motor aswell, so you should have a significant safety margin as far as what it was designed to handle.? That you intend to use it far below its rated capacity generally means you can expect an extended service life of the part, another advantage.? And in closing I will say that I feel as you are doing the right thing thinking outside of the box. I usually build all my own stuff out of components rather than buying sets, often using parts that meet the specs I need that were manufactured for another application. This is what allows me to afford my projects, because everyone here will attest that none of this stuff is inexpensive to begin with, and getting others to do the engineering or sell you a "specialty" part can make the war chest dry with a quickness.?
Hope this helps! On Tue, Jun 9, 2020 at 8:43 AM, Bob Jennings <heatnh@...> wrote: John, can't comment on whether that contactor is correct for your application. This is the contactor thst came with my 10KW setup. Perhaps you could cross reference it.
I'd like to put a contactor or solid state relay between my battery and motor so that I can use a simple toggle switch to turn on/off the battery.? ?Longer term, the bms could disable the battery, or I could even select between battery banks.
But for now, starting simple with an electrically controlled switch for the battery.
I'm using a 48V system. Typical max operating current may be as low as 20A, but could get spikes up to 50A.
I've looked at DC solid state relays.? And even found some rated up to 48V.? The problem is that when you read the fine print and reviews - even the 100A? SSR's are not rated for anywhere near that amount of current for constant usage.? ?(arrrgh!!)
I then started looking at "contactors", and eventually ended up looking at 48V golf cart solenoids. I've always thought of a "solenoid" in this case as being a really big relay.? It looks like the 48V golf cart solenoids should work for this application:
(Note - I'm on fresh water, and the solenoid would be in a plastic case - so I'm not worried about corrosion.)
Is that what I'm looking for, or do I need something that's more "heavy duty"? I saw references to using a flyback diode on the control contacts - and that seemed like a good idea.? Anything else I need to know?
Thanks! John
|
Re: battery chargers for AGM?
I bought a NOCO Genius GX4820 that has settings for both AGM as
well as LIFPO batteries.? Look at Amazon
On 6/9/2020 10:08 AM, Ryan Sweet wrote:
toggle quoted message
Show quoted text
Any recommendations on a battery charger for 48v
200ah AGM?
?Here's another more affordable option than
thunderstrucks offering:
Looks like
yours is still lighter on the coffer though.?
I know that
there are some that fortunate enough for see "money as no
object", and am happy for them. But personally, I spend a
chunk of my time looking for the ways I can do what I am
trying to do affordably, and using a $40 or $50
cart/industrial relay instead of a specialty $125 relay that
does the same job is a perfect example of the kind of though
that makes these projects even possible on my budget.?
If you are using a 48v
nominal bank with a max amp draw of 50a, but the golf
cart contactor should work just fine as the motor that
the golf cart relay was designed to potentially energize
has a significantly higher amp draw. I looked up the
ezgo cart motors yesterday, and the smallest 48v motor
they sell is 4hp, so 4hpx750w=3000w
3000w/48v=62.5a
They
use the same relay on the 8.5hp motor aswell, so you
should have a significant safety margin as far as what
it was designed to handle.?
That
you intend to use it far below its rated capacity
generally means you can expect an extended service
life of the part, another advantage.?
And
in closing I will say that I feel as you are doing the
right thing thinking outside of the box. I usually
build all my own stuff out of components rather than
buying sets, often using parts that meet the specs I
need that were manufactured for another application.
This is what allows me to afford my projects, because
everyone here will attest that none of this stuff is
inexpensive to begin with, and getting others to do
the engineering or sell you a "specialty" part can
make the war chest dry with a quickness.?
Hope
this helps!
On Tue, Jun 9, 2020 at 8:43 AM, Bob
Jennings
John, can't comment on whether that
contactor is correct for your application.
This is the contactor thst came with
my 10KW setup. Perhaps you could cross
reference it.
I'd like to put a
contactor or solid state relay
between my battery and motor so
that I can use a simple toggle
switch to turn on/off the
battery.? ?Longer term, the bms
could disable the battery, or I
could even select between battery
banks.
But for now, starting
simple with an electrically
controlled switch for the battery.
I'm using a 48V
system.
Typical max operating
current may be as low as 20A, but
could get spikes up to 50A.
I've looked at DC
solid state relays.? And even
found some rated up to 48V.? The
problem is that when you read the
fine print and reviews - even the
100A? SSR's are not rated for
anywhere near that amount of
current for constant usage.?
?(arrrgh!!)
I then started
looking at "contactors", and
eventually ended up looking at 48V
golf cart solenoids.
I've always thought
of a "solenoid" in this case as
being a really big relay.? It
looks like the 48V golf cart
solenoids should work for this
application:
(Note - I'm on fresh
water, and the solenoid would be
in a plastic case - so I'm not
worried about corrosion.)
Is that what I'm
looking for, or do I need
something that's more "heavy
duty"?
I saw references to
using a flyback diode on the
control contacts - and that seemed
like a good idea.? Anything else I
need to know?
Thanks!
John
|
Re: battery chargers for AGM?
I have one left over from my upgrade to lifepo4. ? I bought it from thunderstruck?
toggle quoted message
Show quoted text
On Jun 9, 2020, at 7:08 AM, Ryan Sweet < ryan@...> wrote: Any recommendations on a battery charger for 48v 200ah AGM? ?Here's another more affordable option than thunderstrucks offering: Looks like yours is still lighter on the coffer though.? I know that there are some that fortunate enough for see "money as no object", and am happy for them. But personally, I spend a chunk of my time looking for the ways I can do what I am trying to do affordably, and using a $40 or $50 cart/industrial relay instead of a specialty $125 relay that does the same job is a perfect example of the kind of though that makes these projects even possible on my budget.? If you are using a 48v nominal bank with a max amp draw of 50a, but the golf cart contactor should work just fine as the motor that the golf cart relay was designed to potentially energize has a significantly higher amp draw. I looked up the ezgo cart motors yesterday, and the smallest 48v motor they sell is 4hp, so 4hpx750w=3000w 3000w/48v=62.5a They use the same relay on the 8.5hp motor aswell, so you should have a significant safety margin as far as what it was designed to handle.? That you intend to use it far below its rated capacity generally means you can expect an extended service life of the part, another advantage.? And in closing I will say that I feel as you are doing the right thing thinking outside of the box. I usually build all my own stuff out of components rather than buying sets, often using parts that meet the specs I need that were manufactured for another application. This is what allows me to afford my projects, because everyone here will attest that none of this stuff is inexpensive to begin with, and getting others to do the engineering or sell you a "specialty" part can make the war chest dry with a quickness.?
Hope this helps! On Tue, Jun 9, 2020 at 8:43 AM, Bob Jennings John, can't comment on whether that contactor is correct for your application. This is the contactor thst came with my 10KW setup. Perhaps you could cross reference it.
I'd like to put a contactor or solid state relay between my battery and motor so that I can use a simple toggle switch to turn on/off the battery.? ?Longer term, the bms could disable the battery, or I could even select between battery banks.
But for now, starting simple with an electrically controlled switch for the battery.
I'm using a 48V system. Typical max operating current may be as low as 20A, but could get spikes up to 50A.
I've looked at DC solid state relays.? And even found some rated up to 48V.? The problem is that when you read the fine print and reviews - even the 100A? SSR's are not rated for anywhere near that amount of current for constant usage.? ?(arrrgh!!)
I then started looking at "contactors", and eventually ended up looking at 48V golf cart solenoids. I've always thought of a "solenoid" in this case as being a really big relay.? It looks like the 48V golf cart solenoids should work for this application:
(Note - I'm on fresh water, and the solenoid would be in a plastic case - so I'm not worried about corrosion.)
Is that what I'm looking for, or do I need something that's more "heavy duty"? I saw references to using a flyback diode on the control contacts - and that seemed like a good idea.? Anything else I need to know?
Thanks! John
|
I don¡¯t work for a company that has anything to do with electric conversion etc. ?but I would like to say here that having a resource that has the knowledge to make these systems work reliably and safely has value. ?Not only do they provide the knowledge that can help people through these projects but they also set up a distribution path that motivates suppliers to make changes to products to meet our needs and address shortcomings we could use. ?As individuals looking to DIY with the least out of pocket costs we have next to zero buying power and are stuck with whatever we can find. ?Keeping specialized companies for what we need has value and it employs people that we want to see employed. ?Just saying there is an argument to be made to pay people for their expertise. ?I know you guys don¡¯t want to be providing support in years to come. ?By all means we should help one another and for those that really can¡¯t afford it I think it¡¯s great you are able to do it. ?I just don¡¯t think telling the readers of our threads that it¡¯s the smart way to do it is all that accurate.
Just my opinion and I know they are like a holes. ?We all have them and most stink ? Larry
toggle quoted message
Show quoted text
On Jun 9, 2020, at 10:02 AM, Ryan G via groups.io <ryanwestbrookcary1@...> wrote:
?Here's another more affordable option than thunderstrucks offering: Looks like yours is still lighter on the coffer though.? I know that there are some that fortunate enough for see "money as no object", and am happy for them. But personally, I spend a chunk of my time looking for the ways I can do what I am trying to do affordably, and using a $40 or $50 cart/industrial relay instead of a specialty $125 relay that does the same job is a perfect example of the kind of though that makes these projects even possible on my budget.? On Tue, Jun 9, 2020 at 9:37 AM, ryanwestbrookcary1@... <ryanwestbrookcary1@...> wrote: If you are using a 48v nominal bank with a max amp draw of 50a, but the golf cart contactor should work just fine as the motor that the golf cart relay was designed to potentially energize has a significantly higher amp draw. I looked up the ezgo cart motors yesterday, and the smallest 48v motor they sell is 4hp, so 4hpx750w=3000w 3000w/48v=62.5a They use the same relay on the 8.5hp motor aswell, so you should have a significant safety margin as far as what it was designed to handle.? That you intend to use it far below its rated capacity generally means you can expect an extended service life of the part, another advantage.? And in closing I will say that I feel as you are doing the right thing thinking outside of the box. I usually build all my own stuff out of components rather than buying sets, often using parts that meet the specs I need that were manufactured for another application. This is what allows me to afford my projects, because everyone here will attest that none of this stuff is inexpensive to begin with, and getting others to do the engineering or sell you a "specialty" part can make the war chest dry with a quickness.?
Hope this helps! On Tue, Jun 9, 2020 at 8:43 AM, Bob Jennings <heatnh@...> wrote: John, can't comment on whether that contactor is correct for your application. This is the contactor thst came with my 10KW setup. Perhaps you could cross reference it.
I'd like to put a contactor or solid state relay between my battery and motor so that I can use a simple toggle switch to turn on/off the battery.? ?Longer term, the bms could disable the battery, or I could even select between battery banks.
But for now, starting simple with an electrically controlled switch for the battery.
I'm using a 48V system. Typical max operating current may be as low as 20A, but could get spikes up to 50A.
I've looked at DC solid state relays.? And even found some rated up to 48V.? The problem is that when you read the fine print and reviews - even the 100A? SSR's are not rated for anywhere near that amount of current for constant usage.? ?(arrrgh!!)
I then started looking at "contactors", and eventually ended up looking at 48V golf cart solenoids. I've always thought of a "solenoid" in this case as being a really big relay.? It looks like the 48V golf cart solenoids should work for this application:
(Note - I'm on fresh water, and the solenoid would be in a plastic case - so I'm not worried about corrosion.)
Is that what I'm looking for, or do I need something that's more "heavy duty"? I saw references to using a flyback diode on the control contacts - and that seemed like a good idea.? Anything else I need to know?
Thanks! John
|
Re: battery chargers for AGM?
Any recommendations on a battery charger for 48v 200ah AGM?
toggle quoted message
Show quoted text
On Jun 9, 2020, at 07:02, Ryan G via groups.io <ryanwestbrookcary1@...> wrote:
?Here's another more affordable option than thunderstrucks offering: Looks like yours is still lighter on the coffer though.? I know that there are some that fortunate enough for see "money as no object", and am happy for them. But personally, I spend a chunk of my time looking for the ways I can do what I am trying to do affordably, and using a $40 or $50 cart/industrial relay instead of a specialty $125 relay that does the same job is a perfect example of the kind of though that makes these projects even possible on my budget.? On Tue, Jun 9, 2020 at 9:37 AM, ryanwestbrookcary1@... <ryanwestbrookcary1@...> wrote: If you are using a 48v nominal bank with a max amp draw of 50a, but the golf cart contactor should work just fine as the motor that the golf cart relay was designed to potentially energize has a significantly higher amp draw. I looked up the ezgo cart motors yesterday, and the smallest 48v motor they sell is 4hp, so 4hpx750w=3000w 3000w/48v=62.5a They use the same relay on the 8.5hp motor aswell, so you should have a significant safety margin as far as what it was designed to handle.? That you intend to use it far below its rated capacity generally means you can expect an extended service life of the part, another advantage.? And in closing I will say that I feel as you are doing the right thing thinking outside of the box. I usually build all my own stuff out of components rather than buying sets, often using parts that meet the specs I need that were manufactured for another application. This is what allows me to afford my projects, because everyone here will attest that none of this stuff is inexpensive to begin with, and getting others to do the engineering or sell you a "specialty" part can make the war chest dry with a quickness.?
Hope this helps! On Tue, Jun 9, 2020 at 8:43 AM, Bob Jennings <heatnh@...> wrote: John, can't comment on whether that contactor is correct for your application. This is the contactor thst came with my 10KW setup. Perhaps you could cross reference it.
I'd like to put a contactor or solid state relay between my battery and motor so that I can use a simple toggle switch to turn on/off the battery.? ?Longer term, the bms could disable the battery, or I could even select between battery banks.
But for now, starting simple with an electrically controlled switch for the battery.
I'm using a 48V system. Typical max operating current may be as low as 20A, but could get spikes up to 50A.
I've looked at DC solid state relays.? And even found some rated up to 48V.? The problem is that when you read the fine print and reviews - even the 100A? SSR's are not rated for anywhere near that amount of current for constant usage.? ?(arrrgh!!)
I then started looking at "contactors", and eventually ended up looking at 48V golf cart solenoids. I've always thought of a "solenoid" in this case as being a really big relay.? It looks like the 48V golf cart solenoids should work for this application:
(Note - I'm on fresh water, and the solenoid would be in a plastic case - so I'm not worried about corrosion.)
Is that what I'm looking for, or do I need something that's more "heavy duty"? I saw references to using a flyback diode on the control contacts - and that seemed like a good idea.? Anything else I need to know?
Thanks! John
|
Here's another more affordable option than thunderstrucks offering: Looks like yours is still lighter on the coffer though.? I know that there are some that fortunate enough for see "money as no object", and am happy for them. But personally, I spend a chunk of my time looking for the ways I can do what I am trying to do affordably, and using a $40 or $50 cart/industrial relay instead of a specialty $125 relay that does the same job is a perfect example of the kind of though that makes these projects even possible on my budget.?
On Tue, Jun 9, 2020 at 9:37 AM, ryanwestbrookcary1@... <ryanwestbrookcary1@...> wrote: If you are using a 48v nominal bank with a max amp draw of 50a, but the golf cart contactor should work just fine as the motor that the golf cart relay was designed to potentially energize has a significantly higher amp draw. I looked up the ezgo cart motors yesterday, and the smallest 48v motor they sell is 4hp, so 4hpx750w=3000w 3000w/48v=62.5a They use the same relay on the 8.5hp motor aswell, so you should have a significant safety margin as far as what it was designed to handle.? That you intend to use it far below its rated capacity generally means you can expect an extended service life of the part, another advantage.? And in closing I will say that I feel as you are doing the right thing thinking outside of the box. I usually build all my own stuff out of components rather than buying sets, often using parts that meet the specs I need that were manufactured for another application. This is what allows me to afford my projects, because everyone here will attest that none of this stuff is inexpensive to begin with, and getting others to do the engineering or sell you a "specialty" part can make the war chest dry with a quickness.?
Hope this helps! On Tue, Jun 9, 2020 at 8:43 AM, Bob Jennings <heatnh@...> wrote: John, can't comment on whether that contactor is correct for your application. This is the contactor thst came with my 10KW setup. Perhaps you could cross reference it.
I'd like to put a contactor or solid state relay between my battery and motor so that I can use a simple toggle switch to turn on/off the battery.? ?Longer term, the bms could disable the battery, or I could even select between battery banks.
But for now, starting simple with an electrically controlled switch for the battery.
I'm using a 48V system. Typical max operating current may be as low as 20A, but could get spikes up to 50A.
I've looked at DC solid state relays.? And even found some rated up to 48V.? The problem is that when you read the fine print and reviews - even the 100A? SSR's are not rated for anywhere near that amount of current for constant usage.? ?(arrrgh!!)
I then started looking at "contactors", and eventually ended up looking at 48V golf cart solenoids. I've always thought of a "solenoid" in this case as being a really big relay.? It looks like the 48V golf cart solenoids should work for this application:
(Note - I'm on fresh water, and the solenoid would be in a plastic case - so I'm not worried about corrosion.)
Is that what I'm looking for, or do I need something that's more "heavy duty"? I saw references to using a flyback diode on the control contacts - and that seemed like a good idea.? Anything else I need to know?
Thanks! John
|
If you are using a 48v nominal bank with a max amp draw of 50a, but the golf cart contactor should work just fine as the motor that the golf cart relay was designed to potentially energize has a significantly higher amp draw. I looked up the ezgo cart motors yesterday, and the smallest 48v motor they sell is 4hp, so 4hpx750w=3000w 3000w/48v=62.5a They use the same relay on the 8.5hp motor aswell, so you should have a significant safety margin as far as what it was designed to handle.? That you intend to use it far below its rated capacity generally means you can expect an extended service life of the part, another advantage.? And in closing I will say that I feel as you are doing the right thing thinking outside of the box. I usually build all my own stuff out of components rather than buying sets, often using parts that meet the specs I need that were manufactured for another application. This is what allows me to afford my projects, because everyone here will attest that none of this stuff is inexpensive to begin with, and getting others to do the engineering or sell you a "specialty" part can make the war chest dry with a quickness.?
On Tue, Jun 9, 2020 at 8:43 AM, Bob Jennings <heatnh@...> wrote: John, can't comment on whether that contactor is correct for your application. This is the contactor thst came with my 10KW setup. Perhaps you could cross reference it.
I'd like to put a contactor or solid state relay between my battery and motor so that I can use a simple toggle switch to turn on/off the battery.? ?Longer term, the bms could disable the battery, or I could even select between battery banks.
But for now, starting simple with an electrically controlled switch for the battery.
I'm using a 48V system. Typical max operating current may be as low as 20A, but could get spikes up to 50A.
I've looked at DC solid state relays.? And even found some rated up to 48V.? The problem is that when you read the fine print and reviews - even the 100A? SSR's are not rated for anywhere near that amount of current for constant usage.? ?(arrrgh!!)
I then started looking at "contactors", and eventually ended up looking at 48V golf cart solenoids. I've always thought of a "solenoid" in this case as being a really big relay.? It looks like the 48V golf cart solenoids should work for this application:
(Note - I'm on fresh water, and the solenoid would be in a plastic case - so I'm not worried about corrosion.)
Is that what I'm looking for, or do I need something that's more "heavy duty"? I saw references to using a flyback diode on the control contacts - and that seemed like a good idea.? Anything else I need to know?
Thanks! John
|
Reuben Trane