Re: [Electric Boats] Picking batteries - NiFe
Kevin,
I did the math with the data on the link that you provided. One 100Ah 1.2V cell weighs 4.9Kg (dry weight?), so 10 dry cells would weigh 49Kg which is 107.8 pounds. That battery would be rated for 1200Wh which is 11.1 Wh/lb. But the page says that you need to add distilled water to make them work, and of course the link doesn't say how much. If a 100Ah cell takes only 2 cups of water, then one cell is close to 12 pounds and we're back to 10Wh/lb. Looking at the 200Ah cells, they are 26.4 pounds dry or 264 pounds for a dry 200Ah 12V (2400kWh) battery. Add water and you're probably past 280 pounds or 8.5Wh/lb.
Alternatively, a T-105 weighs 62 pounds (according to Trojan) and is rated for 225Ah @ 6V or 1350Wh. That works out to 21.8 Wh/lb. Take two in series and you've got a 225Ah 12V battery that weighs 124 pounds.
Are you really sure that size doesn't matter? Lets compare the 200Ah 12V NiFe to the 225Ah 12V T-105s
2400Wh NiFe = 13.2" x 32" x 13.6" = 5745 cu. inches, 280 pounds
2700Wh T-105 = 10.4" x 14.3" x 10.7" = 1591 cu. inches, 124 pounds
The NiFe battery is more than 3 times the volume of the two T-105s for 10% less rated capacity.
I'm not passing any judgement, just doing the math so that people can decide for themselves.
Fair winds,
Eric
Marina del Rey, CA
toggle quoted message
Show quoted text
--- In electricboats@..., Kevin Pemberton <pembertonkevin@...> wrote:
Eric,
According to this page batteries supplied by Ironcorebatteries
100Ah weigh almost 100lbs
for 12v pack. T 105 6v about 67lbs. No problem discharging NiFe to 80%,
big problem discharging the T 105 to 80% over the long haul. Was two
optima blue tops. 120 lbs for 100Ah when large discharges are not
figured in. Where is weight a problem?
mount in wood mount because fumes are non corrosive, can be mounted
anyplace if vented outside. Size becomes no problem.
And yes I see the weight problem with anything other than batteries
easily distroyed by over charge or over discharge.
Kevin Pemberton
|
[Electric Boats] Re: New Electric Cat
That link was so good I added it to my Favorites list.
They look damn seaworthy too!
Thanks Michael.
toggle quoted message
Show quoted text
--- In electricboats@..., "Mike Allison" <mysloop@...> wrote:
Higher than I was thinking too.
Guess I'll keep looking at and mabe build one myself.
Michael Allison
|
[Electric Boats] Re: New Electric Cat
Hi Mike,
I have come across used Gemini's from $25,000 to $75,000. That would leave $75,000 to $125,000 to by E-pod, refurb boat and pay cruising expenses for a long while instead of the Blue Planet 32.
I dont want to put it down. I would love a bunch of used ones to flood the market in 5 to ten years. I might be able to swing that.
Here is a link to a Gemini owner who dumped the diesel for the
E-pod.
Don
toggle quoted message
Show quoted text
--- In electricboats@..., "Mike Allison" <mysloop@...> wrote:
Higher than I was thinking too.
Guess I'll keep looking at and mabe build one myself.
Michael Allison
|
Quote: Has anyone had experience with the Torqeedo motors getting dunked?
I have a customer who uses an 801 Travel to move his daysailer in calms. He has had it fail twice due to saltwater-related issues.
He now keeps a plastic bag over the tiller.
He also bought a 2 Hp Honda to keep operational when the Torqueedo is in the shop.
His is an early model, I understand. Might not be a problem anymore.
-Tom
|
[Electric Boats] Re: New Electric Cat
Higher than I was thinking too.
Guess I'll keep looking at ?and
mabe build one myself.
?
Michael Allison
|
Re: [Electric Boats] Picking batteries - NiFe
I was interested enough in this to do some research on NiFe.? I
decided to compare them to the T-105 6v.
To get 450Ah with T-106 you need 4 of them. Total cost?? $600, total
weight 248lbs, total volume 1.86 CubicFeet, life span 4years avg
To get 450Ah with NiFe you need 10 of them.? Total cost $3160, total
weight 485lbs, total volume 6.07 CubicFeet, life span 100+ years
So at this Amp Hour level, NiFe is 2 times the weight, 3 times the
volume and 5 times the cost.
For taking a house off the grid, its a NO BRAINER. NiFe all the way!
For a boat, a bit of a hard sell but maybe.
Now if you were building a new boat and could incorporate the weight
and placement of the NiFe batteries into the ballast somehow, now
that would be a major plus.? If they never need to be replaced, as
claimed, seems completely doable to me.....
That thought process with a diesel-electric system to charge and use
for propulsion seems like a win-win if you can afford it.
William
toggle quoted message
Show quoted text
?
Eric,
According to this page batteries supplied by
Ironcorebatteries
100Ah weigh almost 100lbs
for 12v pack. T 105 6v about 67lbs.? No problem
discharging NiFe to
80%, big problem discharging the T 105 to 80% over the
long haul.? Was
two optima blue tops. 120 lbs for 100Ah when large
discharges are not
figured in.? Where is weight a problem?
mount in wood mount because fumes are non corrosive, can
be mounted
anyplace if vented outside. Size becomes no problem.
And yes I see the weight problem with anything other than
batteries
easily distroyed by over charge or over discharge.
Kevin Pemberton
On 11/15/2010 01:31 PM, Eric wrote:
?
Kevin,
Based on your criteria, the NiFe batteries do seem
like a reasonable
alternative. But I have always been concerned with
weight in any mobile
installation. I do agree that they seem excellent
alternatives for home
and business installations.
I don't know how heavy your current RV battery bank
is, but do you
really want to increase that weight by 100 to 150
percent for the same
rated capacity? Battery volume will also be a concern,
do you have
space for battery bank that is twice the physical
size?
Many of the converted boats here have battery banks
that are around
10kWh and weigh about 500 pounds. At 1000 pounds or
more, NiFe will
start having a bigger negative effect on performance,
not only in
electric range, but sailing performance too (if
applicable). For me,
the cost, lifecycles and fault tolerance are lesser
concerns than size
and weight. Most car and boat manufacturers that are
venturing into
this market seem to agree.
That said, if your conversion is spec'ed for these
batteries, then more
power to you (no pun intended). I'm looking forward to
your actual
observed performance data when you finish your boat.
Fair winds,
Eric
Marina del Rey, CA
.
--
Ubuntu10.04, Acer AspireOne, Virgin Mobile 3G Broadband2go.
Doesn't get any better than this!
|
[Electric Boats] Re: New Electric Cat
Hi Eric, Sally and all,
I got an E-mail from Gene at Planet Blue Catamarans but still sparse on specs.
They are targeting $149k for basic version with many options for electronics, additional batteries, generators, solar/wind power, kites, amd custom interiors.
Hulls 4' wide, bridge deck just under 8' and demountable.
Gene says interior woodwork is nearly done and looks magnificent... semi-gloss teak, etc. Test drives can be scheduled off his dock in Beaufort, North Carolina in December.
It is more pricey than I hoped.
Don
toggle quoted message
Show quoted text
--- In electricboats@..., "Eric" <ewdysar@...> wrote:
Hi Sally,
It's good to hear that a major supplier has broken the $1.00/Wh barrier for the latest generation of mainstream high-tech batteries.
I am curious about the voltage that they use to rate their batteries. My Thundersky cells are rated as 3.2V and they do have a resting voltage of 3.31V three months since their last charge. But in use, the voltage usually closer to 3.1V at any regular loads. With 16 cells, I could rate my battery pack as it's resting voltage of 53V, but I use 50V to be conservative. That choice means that I rate my capacity at 8kWh instead of 8.5kWh @ 53V/pack or 8.2kWh @ 3.2V/cell. So I wonder what the specifics are around their 25.9V rating. I know that it is just a nit-pick kind of thing, but since they got so specific...
Fair winds,
Eric
Marina del Rey, CA
--- In electricboats@..., Sally Reuther <smreuther@> wrote:
We spoke with Torqeedo at IBEX and went to their "unveiling" of the new
Power 26-104. The specs are:
2.7 kWh (25.9 v, 104 Ah)
44 lbs
Dimensions are: 8.0" x 21.3" x 9.4"
Price: $2,499.00
Pretty nice - if you can afford the price.
|
Re: [Electric Boats] Picking batteries - NiFe
Eric,
According to this page batteries supplied by Ironcorebatteries
100Ah weigh almost 100lbs
for 12v pack. T 105 6v about 67lbs.? No problem discharging NiFe to
80%, big problem discharging the T 105 to 80% over the long haul.? Was
two optima blue tops. 120 lbs for 100Ah when large discharges are not
figured in.? Where is weight a problem?
mount in wood mount because fumes are non corrosive, can be mounted
anyplace if vented outside. Size becomes no problem.
And yes I see the weight problem with anything other than batteries
easily distroyed by over charge or over discharge.
Kevin Pemberton
On 11/15/2010 01:31 PM, Eric wrote:
?
Kevin,
Based on your criteria, the NiFe batteries do seem like a reasonable
alternative. But I have always been concerned with weight in any mobile
installation. I do agree that they seem excellent alternatives for home
and business installations.
I don't know how heavy your current RV battery bank is, but do you
really want to increase that weight by 100 to 150 percent for the same
rated capacity? Battery volume will also be a concern, do you have
space for battery bank that is twice the physical size?
Many of the converted boats here have battery banks that are around
10kWh and weigh about 500 pounds. At 1000 pounds or more, NiFe will
start having a bigger negative effect on performance, not only in
electric range, but sailing performance too (if applicable). For me,
the cost, lifecycles and fault tolerance are lesser concerns than size
and weight. Most car and boat manufacturers that are venturing into
this market seem to agree.
That said, if your conversion is spec'ed for these batteries, then more
power to you (no pun intended). I'm looking forward to your actual
observed performance data when you finish your boat.
Fair winds,
Eric
Marina del Rey, CA
.
--
Ubuntu10.04, Acer AspireOne, Virgin Mobile 3G Broadband2go.
Doesn't get any better than this!
|
Has anyone had experience with the Torqeedo motors getting dunked? It seems their position on the brackets could leave them under water if a fat wave breaks on the stern. I've seen the Honda outboard on a customer's Rawson go a foot under water when the going gets rough, despite the long shaft. Part of the reason was that his motor was mounted on the swim platform, holding it away from the buoyancy boat. By the time the wave lifted the boat, the motor had been completely covered. Remarkably, the Honda never missed a beat.
If the hulls could be forked, the motors could then be moved inboard. That would allow a incoming wave to lift the stern.
Just a thought...
Arby
From: Eric
To: electricboats@...
Sent: Mon, November 15, 2010 10:32:06 AM
Subject: [Electric Boats] Re: New Electric Cat
?
Thanks for the link, Don.
It does look interesting, though they are not giving much is the way of technical specs on that page.
We do know that they are using Torqeedo Cruise 2.0 motors running on 24V. I probably would have chosen Cruise 4.0s but its their boat, not mine. I would be concerned about having the power to manuever in crosswinds or ther adverse conditions. Their reference to Lithium manganese batteries leads me to believe that they are using Torqeedo batteries too, nice product but fairly expensive (says someone who bought an 8kWh LiFePO4 battery bank). I wonder how big their banks are?
I like that they claim virtually unlimited range due to solar, wind and "whisper quiet generators". Since this board has discussed the practicality of solar and wind for this type of boat, I would suggest that the generators would be responsible for most of "extended range" drive load while under way. Their drives are only 2kW units, and we know that a Honda generator can deliver up to about 1500W through off-the-shelf parts. Add 1000W of solar and the boat would be able to operate at full throttle powered by gasoline and sunlight.
I can hardly wait to hear about some of their solutions to the various issues that we're all working on here. Like you, I'm interested to see what their performance numbers (watts to knots) will be when the boat is normally loaded.
Fair winds,
Eric
Marina del Rey, CA
--- In electricboats@..., "Don Parsons" wrote:
>
> Came across this on the Multihulls Magazine website.
> It appears to be a partnering between Steve Trkla, president of the North American division of Torqueedo and Gene Carletta of Blue Planet Catamarans.
> It looked pretty cool to me so I have e-mailed them asking for more info.
> I will post more when they respond.
>
>
>
>
> Don Parsons
>
|
[Electric Boats] Re: New Electric Cat
Hi Sally,
It's good to hear that a major supplier has broken the $1.00/Wh barrier for the latest generation of mainstream high-tech batteries.
I am curious about the voltage that they use to rate their batteries. My Thundersky cells are rated as 3.2V and they do have a resting voltage of 3.31V three months since their last charge. But in use, the voltage usually closer to 3.1V at any regular loads. With 16 cells, I could rate my battery pack as it's resting voltage of 53V, but I use 50V to be conservative. That choice means that I rate my capacity at 8kWh instead of 8.5kWh @ 53V/pack or 8.2kWh @ 3.2V/cell. So I wonder what the specifics are around their 25.9V rating. I know that it is just a nit-pick kind of thing, but since they got so specific...
Fair winds,
Eric
Marina del Rey, CA
toggle quoted message
Show quoted text
--- In electricboats@..., Sally Reuther <smreuther@...> wrote:
We spoke with Torqeedo at IBEX and went to their "unveiling" of the new
Power 26-104. The specs are:
2.7 kWh (25.9 v, 104 Ah)
44 lbs
Dimensions are: 8.0" x 21.3" x 9.4"
Price: $2,499.00
Pretty nice - if you can afford the price.
|
[Electric Boats] Re: New Electric Cat
Review of the Torqeedo Power 26-104 lithium battery:
===========================================================
The power 26 104 is Torqeedos latest lithium ion battery for the cruise range of 24 Volt electric outboards. The power range of Lithium batteries has extremely high energy density, resistance to high current, safe and is maintenance-free.
As the use and development of lithium Ion technology is becoming more prevalent and so the cost is coming down. It is still expensive as this 24 volt battery from Torqeedo is $2,499 but the benefits seen below may make it an option for many.
if you're looking for a simple green solution for your small boat or inflatable, the " Torqeedo outboards" " , powered by this new high power-density and cost-effective battery, are something you should consider.
In addition to powering the Torqeedo you can power lights and electronics with a DC to DC converter. Torqeedo Power batteries remain charged for several months even when they are stored.
Features:
1. Light weight
2. Smaller space
3. IP67 fully waterproof
4. Almost Indestructible
5. No memeory
6. Fast Charge Ability
7. Safe & Green
8. Zero Maintenance
9. Temperature Tolerant
10. High Energy Density
Torqeedo's Description
NEW LITHIUM BATTERY SETS NEW STANDARDS IN PERFORMANCE,
SAFETY AND VALUE
Lithium batteries are the technology of choice when it comes to providing more energy from smaller, lighter battery banks. Now the leader in electric outboards, Torqeedo, sets new standards with its innovative Power 26-104 lithium manganese battery.
Delivering 2,685 watt-hours from a weight of only 44 lbs., the new Power 26-104 features four times the energy per pound of battery weight compared to conventional lead-gel or AGM batteries. It outperforms other lithium batteries on the market.
The integrated battery management system (BMS) is in a class of its own. In addition to typical functions of a BMS, like cell balancing, the new Torqeedo BMS protects the battery against overcharge, overvoltage, overheating, deep discharge, wrong polarity and other potential causes of damage or danger.
Torqeedo Power 26-104 is uncompromisingly designed for marine use. It is waterproof to IP 67 standards, so it can be completely submersed at 3ft for 30 minutes and still function properly. It will also shut itself down if submersed longer to avoid dangerous galvanic effects. Superior safety aspects of the new battery encompass proven and secure battery chemistry, advanced safety electronics, as well as unique hardware protection of each individual battery-cell.
Torqeedos new Power 26-104 lithium battery retails for $2,499. When weighed against the capacity of the battery, this represents a price of $0.93 per watt-hour, making it an extremely economical offer when compared to other lithium batteries on the market.
|
Re: [Electric Boats] Re: New Electric Cat
We spoke with Torqeedo at IBEX and went to their "unveiling" of the new Power 26-104. ?The specs are: 2.7 kWh (25.9 v, 104 Ah) 44 lbs Dimensions are: 8.0" x 21.3" x 9.4"
Price: $2,499.00
Pretty nice - if you can afford the price.
On Mon, Nov 15, 2010 at 1:32 PM, Eric <ewdysar@...> wrote:
?
Thanks for the link, Don.
It does look interesting, though they are not giving much is the way of technical specs on that page.
We do know that they are using Torqeedo Cruise 2.0 motors running on 24V. I probably would have chosen Cruise 4.0s but its their boat, not mine. I would be concerned about having the power to manuever in crosswinds or ther adverse conditions. Their reference to Lithium manganese batteries leads me to believe that they are using Torqeedo batteries too, nice product but fairly expensive (says someone who bought an 8kWh LiFePO4 battery bank). I wonder how big their banks are?
I like that they claim virtually unlimited range due to solar, wind and "whisper quiet generators". Since this board has discussed the practicality of solar and wind for this type of boat, I would suggest that the generators would be responsible for most of "extended range" drive load while under way. Their drives are only 2kW units, and we know that a Honda generator can deliver up to about 1500W through off-the-shelf parts. Add 1000W of solar and the boat would be able to operate at full throttle powered by gasoline and sunlight.
I can hardly wait to hear about some of their solutions to the various issues that we're all working on here. Like you, I'm interested to see what their performance numbers (watts to knots) will be when the boat is normally loaded.
Fair winds,
Eric
Marina del Rey, CA
--- In electricboats@..., "Don Parsons" wrote:
>
> Came across this on the Multihulls Magazine website.
> It appears to be a partnering between Steve Trkla, president of the North American division of Torqueedo and Gene Carletta of Blue Planet Catamarans.
> It looked pretty cool to me so I have e-mailed them asking for more info.
> I will post more when they respond.
>
>
>
>
> Don Parsons
>
|
Re: [Electric Boats] Picking batteries - NiFe
Kevin,
Based on your criteria, the NiFe batteries do seem like a reasonable alternative. But I have always been concerned with weight in any mobile installation. I do agree that they seem excellent alternatives for home and business installations.
I don't know how heavy your current RV battery bank is, but do you really want to increase that weight by 100 to 150 percent for the same rated capacity? Battery volume will also be a concern, do you have space for battery bank that is twice the physical size?
Many of the converted boats here have battery banks that are around 10kWh and weigh about 500 pounds. At 1000 pounds or more, NiFe will start having a bigger negative effect on performance, not only in electric range, but sailing performance too (if applicable). For me, the cost, lifecycles and fault tolerance are lesser concerns than size and weight. Most car and boat manufacturers that are venturing into this market seem to agree.
That said, if your conversion is spec'ed for these batteries, then more power to you (no pun intended). I'm looking forward to your actual observed performance data when you finish your boat.
Fair winds,
Eric
Marina del Rey, CA
toggle quoted message
Show quoted text
--- In electricboats@..., Kevin Pemberton <pembertonkevin@...> wrote:
...I can see the cost thing, but I was thinking the reliable operation due
to simplicity in design....
I have started my savings earmarked for NiFe pack. I have found large
capacity banks just cost more to replace and as was stated, for house
use may be a good option, and that is what I am doing first. In the
future I can add to the bank without concern over battery age so it will
be a win win for me. I am sorry to have brought up the NiFe, I did not
intend for it to turn into a debate. My intent was to re-introduce a
battery type as I wished someone had done here earlier. The house bank
in my motor-home lasts just about 2 years (over 700 cycles), this bank
needs replacement often in my book. My brother reports maintenance on
his house battery claims it in 3 years. For him I recommended optima
batteries because they are pure lead plates and will be what he needs,
but still at close to 200 big ones for the optima, NiFe may still be a
good bet.
Kevin Pemberton
|
Re: [Electric Boats] Picking batteries
When we talk Peukert effect we fail to remember one thing.? As our lead
acid batteries age the Peukert factor changes.? This is not true with
Nickel Iron.? When new the two compare favorably but in time the polish
of an old tech appears to shine. The catch 22 of lead is to keep the
battery maintained we must limit it's ability to deliver over time.?
Any charging continues to plate the plates reducing their ability to
release the charge stored in the plates.?
This is expressed in many ways. We can start with the statement that we
must not mix different age batteries.? We can further show the implied
limits of lead acid by looking up how many times on this list alone, an
age factor with impaired distance traveled, can be cited.
I can see the cost thing, but I was thinking the reliable operation due
to simplicity in design.? Not the battery, but the entire support
thing. No battery I can think of other than NiFe can be abused the way
they can and survive.? One mistake or failure of a charger can
eliminate a complete battery pack while you are getting a nights sleep
with all the other high priced batteries.? One shorted cell in lead
acid can bring down many batteries in your pack. The Iron battery
company down under has smaller Ah batteries that seem a better fit for
some systems.? Don't know what importing them would cost.? I have been
looking more at hybrid than all electric anyhow so don't know how they
fit for most here.? I can bypass the controller with a knife switch to
get in with a NiFe system because I would not need to worry about abuse
and battery failure.
I have started my savings earmarked for NiFe pack.? I have found large
capacity banks just cost more to replace and as was stated, for house
use may be a good option, and that is what I am doing first. In the
future I can add to the bank without concern over battery age so it
will be a win win for me.? I am sorry to have brought up the NiFe, I
did not intend for it to turn into a debate.? My intent was to
re-introduce a battery type as I wished someone had done here earlier.
The house bank in my motor-home lasts just about 2 years (over 700
cycles), this bank needs replacement often in my book.? My brother
reports maintenance on his house battery claims it in 3 years.? For him
I recommended optima batteries because they are pure lead plates and
will be what he needs, but still at close to 200 big ones for the
optima,? NiFe may still be a good bet.
Kevin Pemberton
On 11/14/2010 01:36 PM, Myles Twete wrote:
?
>A
Peukert exponent of 1.00 means that there is no Peukerts effect at all
and that the battery will deliver the same amount of energy at any
discharge rate. I would guess that the Peukert's exponent for Nickel
Iron batteries is higher than 1.00
>Eric
No doubt.?
References online claim virtually no Peukert effect for any of the
Nickel chemistries including NiCd, NiZn, NiMH.
I’m sure he just was
parroting these.? Worse, the weblink he offered drawing folks to his
personal Peukert calculator page does not provide any support for the
1.0 Peukert exponent claim.
?
From the brief
looking I’ve done, I’d guess that the effective Peukert exponent for
NiFe is below 1.05, and once you’re down that low, unless you’re
drawing high-C loads, I don’t think you have to worry much about it.
?
I think the major
beefs against NiFe batteries are:
·????????
Cost
·????????
Relatively
high self-discharge rates
?
And those weigh
enough against them that we don’t appreciate the uber-long life of
them.? Charge/discharge inefficiency isn’t much of an issue for many of
us, but high initial cost and self-discharge rates are.
?
-Myles Twete
--
Ubuntu10.04, Acer AspireOne, Virgin Mobile 3G Broadband2go.
Doesn't get any better than this!
|
Thanks for the link, Don.
It does look interesting, though they are not giving much is the way of technical specs on that page.
We do know that they are using Torqeedo Cruise 2.0 motors running on 24V. I probably would have chosen Cruise 4.0s but its their boat, not mine. I would be concerned about having the power to manuever in crosswinds or ther adverse conditions. Their reference to Lithium manganese batteries leads me to believe that they are using Torqeedo batteries too, nice product but fairly expensive (says someone who bought an 8kWh LiFePO4 battery bank). I wonder how big their banks are?
I like that they claim virtually unlimited range due to solar, wind and "whisper quiet generators". Since this board has discussed the practicality of solar and wind for this type of boat, I would suggest that the generators would be responsible for most of "extended range" drive load while under way. Their drives are only 2kW units, and we know that a Honda generator can deliver up to about 1500W through off-the-shelf parts. Add 1000W of solar and the boat would be able to operate at full throttle powered by gasoline and sunlight.
I can hardly wait to hear about some of their solutions to the various issues that we're all working on here. Like you, I'm interested to see what their performance numbers (watts to knots) will be when the boat is normally loaded.
Fair winds,
Eric
Marina del Rey, CA
toggle quoted message
Show quoted text
--- In electricboats@..., "Don Parsons" <tdparsons@...> wrote:
Came across this on the Multihulls Magazine website.
It appears to be a partnering between Steve Trkla, president of the North American division of Torqueedo and Gene Carletta of Blue Planet Catamarans.
It looked pretty cool to me so I have e-mailed them asking for more info.
I will post more when they respond.
Don Parsons
|
Re: [Electric Boats] New Electric Cat
Yeah, It makes you want to believe doesn't it.
I suspect the interior isn't finished.
Also noticed no one else aboard and calm water.
How fast will it go with a full load in heavy sea and headwind?
Lots left unanswered, but I wouldn't care if the speed dropped
to 5 with full load.
Hoping the price is reasonable.
No answers yet.
Will post when I know more.
Don
toggle quoted message
Show quoted text
--- In electricboats@..., James Sizemore <james@...> wrote:
I like the video, Wish they had pictures of the down below.
On Nov 14, 2010, at 4:09 PM, Don Parsons wrote:
Came across this on the Multihulls Magazine website.
It appears to be a partnering between Steve Trkla, president of the North American division of Torqueedo and Gene Carletta of Blue Planet Catamarans.
It looked pretty cool to me so I have e-mailed them asking for more info.
I will post more when they respond.
Don Parsons
|
Re: [Electric Boats] New Electric Cat
I like the video, ?Wish they had pictures of the down below.?
On Nov 14, 2010, at 4:09 PM, Don Parsons wrote:
?
Came across this on the Multihulls Magazine website.
It appears to be a partnering between Steve Trkla, president of the North American division of Torqueedo and Gene Carletta of Blue Planet Catamarans.
It looked pretty cool to me so I have e-mailed them asking for more info.
I will post more when they respond.
Don Parsons
|
Re: [Electric Boats] Picking batteries
I said about 1, not 1. I also said you can see how this works out using the calculator. The calculator allows you to play with peukert numbers to see what the effects are. at low c values, changing the peukert exponent has no effect. you can prove that with the calculator as well.
Steve Spence
|
Re: [Electric Boats] Picking batteries
The claim was made: "The edison cell has a peukert value of about 1.? You can see how this works out at ____”. Yet no support for this claim was offered except a link to a capacity calculator at the poster’s own website. ? Extraordinary claims (in this case, Peukert Exponent of 1 for NiFe battery chemistry) demand extraordinary proof. A P.E. of 1 effectively requires a battery with zero internal resistance and no irreversible electro-chemical losses. For years, people have claimed P.C. of 1.0 for Lithium also, often parroting "Peukert only applies to Lead Acid".? Only recently has this been disputed. e.g. Peukert Exponents of 1.036 (Valence) and 1.056 (ThunderSky) estimated for . ? Is 1.03-1.06 a Peukert Exponent “about 1”?? That depends of course on your usage---i.e. %C that you will pull current out at.? EV-scale Lithium batteries were claimed for years as having ZERO Peukert effect (Peukert Exponent of 1.0) and yet now we know otherwise.? So why should I (as an Engineer of 30yrs and EV enthusiast for 17yrs) believe an unsupported claim that effectively Peukert doesn’t apply to NiFe?? Sorry, credentials notwithstanding, I am skeptical. ? What do we find on the Web regarding NiXX chemistry and Peukert? It doesn’t take long with resources online to find evidence that NiMH batteries (eg this Panasonic curve below from research paper ) display the Peukert effect---this one with a Peukert Exponent of about 1.035.? Given this for modern NiMH, why should we believe claims that Edison (NiFe) batteries exhibit zero Peukert effect? ?Modern NiFe are somehow better than modern NiMH? ? I can’t tell you the number of times that I’ve heard “Peukert only applies to lead chemistries”. The problem with this: The Peukert Equation was not derived based on the chemistry involved at all.? It was simply based on detailed observations of reduced capacity as a function of current draw and a simplified exponential mathematical model found that matched it pretty well.? Nothing to do with constraining its applicability to lead-acid or that if a battery’s internal resistance is small or zero that the effect doesn’t apply.? Given its empirical basis, the way you “prove” a battery type doesn’t exhibit the effect is to show the data for your new battery type!? You don’t prove it by simply making a claim that the Peukert exponent is about 1.0.? Having said this, sure, a Peukert Exponent of 1.035 is very very good!? And that should be celebrated. ? -Myles ?
toggle quoted message
Show quoted text
-----Original Message-----
From: electricboats@... [mailto:electricboats@...] On Behalf Of Steve Spence
Sent: Sunday, November 14, 2010 12:58 PM
To: electricboats@...
Subject: Re: [Electric Boats] Picking batteries ? If you read battery chemistry engineering books, you would know that Nickel based batteries have a peukert of virtually 1.00. I do not "parrot", I do research and practical experimentation. I've lived off grid for 6 years, and have over 25 years in electronics. I resent the implications otherwise. My calculator is accurate. ? Steve Spence Renewable energy and self sufficiency http://www.green-trust.org http://arduinotronics.blogspot.com/ ? ? ? On 11/14/2010 03:36 PM, Myles Twete wrote: >? > > *>*A Peukert exponent of 1.00 means that there is no Peukerts effect at > all and that the battery will deliver the same amount of energy at any > discharge rate. I would guess that the Peukert's exponent for Nickel > Iron batteries is higher than 1.00 >>Eric > > No doubt.? References online claim virtually no Peukert effect for any > of the Nickel chemistries including NiCd, NiZn, NiMH. > > I’m sure he just was parroting these.? Worse, the weblink he offered > drawing folks to his personal Peukert calculator page does not provide > any support for the 1.0 Peukert exponent claim. > >? > > From the brief looking I’ve done, I’d guess that the effective Peukert > exponent for NiFe is below 1.05, and once you’re down that low, unless > you’re drawing high-C loads, I don’t think you have to worry much about it. > >? > > I think the major beefs against NiFe batteries are: > > ·???????? Cost > > ·???????? Relatively high self-discharge rates > >? > > And those weigh enough against them that we don’t appreciate the > uber-long life of them.? Charge/discharge inefficiency isn’t much of an > issue for many of us, but high initial cost and self-discharge rates are. > >? > > -Myles Twete > >? > > ? ? ------------------------------------ ? Yahoo! Groups Links ? <*> To visit your group on the web, go to: ??? http://groups.yahoo.com/group/electricboats/ ? <*> Your email settings: ??? Individual Email | Traditional ? <*> To change settings online go to: ??? http://groups.yahoo.com/group/electricboats/join ??? (Yahoo! ID required) ? <*> To change settings via email: ??? electricboats-digest@... ????electricboats-fullfeatured@... ? <*> To unsubscribe from this group, send an email to: ??? electricboats-unsubscribe@... ? <*> Your use of Yahoo! Groups is subject to: ??? http://docs.yahoo.com/info/terms/ ?
|
Re: [Electric Boats] Picking batteries
No arguments here…definitely was a conspiracy and capitalism at its finest that led to patent ownership that kept companies from producing large size NiMH batteries for EV use.? Thank you Ovonics and Chevron!? And in my opinion they shot us all in the foot---the head start they had in this was squandered by their keeping this technology from the market and allowed investments in lithium cell technology to jump ahead leaps and bounds.? Few folks rave about NiMH batteries anymore, particularly since the cost of lithium keeps dropping and more and more manufacturers are switching to the easier to make lithiums instead of the NiMH batteries. ? I had a set of NiMH batteries from an EV1----some of the cells were too dead to be revived. I gave them to another fellow EVer here in Portland as I couldn’t trust them and didn’t want to get into mixing/matching cells and having to reband them to the right tension.? My experience with those and smaller scale NiMH batteries led me to not be a big fan of NiMH. I’m not a big fan of lithium either though. ? Waiting to be convinced by quality and pricing. ? -Myles ? ? ?
toggle quoted message
Show quoted text
From: electricboats@... [mailto:electricboats@...] On Behalf Of Don Parsons
Sent: Sunday, November 14, 2010 1:16 PM
To: electricboats@...
Subject: Re: [Electric Boats] Picking batteries? ? Myles,I agree partially,
The exception being for a home powerbank they are the answer even with their high cost and lower performance. In the long run you will save.
What pisses me off is we are being cheated out of their potential.
Not even future potential, but 1970's potential!
That 70's patent is way past expiration but is being held from us. Why.
Our military supposedly is sitting on 40 year old technology. The notion is absurd.
The Be Utility Free Chinese made NiFe is old technology compared
to the Eagle-Picher technology and that is now 40 years old.
Where could NiFe be now if Excide hadn't shelved it.
Sadly we may never know.
If any of you can get your hands on the T-van batteries then I think they would be worth a try in a boat.
I believe there was a post in 2009 by a member who said he had some dead T-van batteries he was going to try to revive. If you read this let us know if they worked.
Hope I didn't rant too much.
Don Parsons
--- In electricboats@..., "Myles Twete" wrote:
>
> >A Peukert exponent of 1.00 means that there is no Peukerts effect at all
> and that the battery will deliver the same amount of energy at any discharge
> rate. I would guess that the Peukert's exponent for Nickel Iron batteries is
> higher than 1.00
> >Eric
>
>
>
> No doubt. References online claim virtually no Peukert effect for any of
> the Nickel chemistries including NiCd, NiZn, NiMH.
>
> I'm sure he just was parroting these. Worse, the weblink he offered drawing
> folks to his personal Peukert calculator page does not provide any support
> for the 1.0 Peukert exponent claim.
>
>
>
> From the brief looking I've done, I'd guess that the effective Peukert
> exponent for NiFe is below 1.05, and once you're down that low, unless
> you're drawing high-C loads, I don't think you have to worry much about it.
>
>
>
> I think the major beefs against NiFe batteries are:
>
> . Cost
>
> . Relatively high self-discharge rates
>
>
>
> And those weigh enough against them that we don't appreciate the uber-long
> life of them. Charge/discharge inefficiency isn't much of an issue for many
> of us, but high initial cost and self-discharge rates are.
>
>
>
> -Myles Twete
>
|
dpyakker
Sally Reuther