lithium battery source/price thread

[john61ct]

WA meaning Western Australia, as opposed to the state of Washington.

[john61ct]

Originally Posted by BruceS

How about everyone stick to an Amp Hour rating at the same "C" rating for starters.... Can be very deceiving .

Since the Peukert coefficient with LFP is so close to 1.0, the difference between the 10-hour and 20-hour rates is minimal

[john61ct]

Originally Posted by redneckrob

Sorry, silly me I thought when he said 170 he was referring to the 170 aH capacity not the 100 amp discharge capacity....given that's a completely different number and all.

Yes, but since Ah has nothing to do with cranking ability

note the LI powerpak jumpstarters that fit in your pocket

his meaning - again with validity - was:

"pretty stupid to have a perfectly good set of cells with that much Ah capacity, restricted by its BMS to only supporting relatively low current rates"

Which I then addressed:

Originally Posted by john61ct

Not the cells, limitation of the BMS. Price goes up a lot putting in a 600A BMS.

They could allow a pair of bypass posts, but then couldn't afford a warranty. Just buy cheap lead for cranking.

[newhaul]

Originally Posted by BruceS

How about everyone stick to an Amp Hour rating at the same "C" rating for starters.... Can be very deceiving .

actually with Lfp it really doesn't matter how you draw out the ah it will deliver the same
With a ( for illustration ) 200ah Lfp I will get the same ah out of it regardless of whether I draw that at 20 amps over 10 hours or I draw at 200amps in one hour.

This is one of the great advantages of the chemistry
( the same works in reverse as well aka charging.

[john61ct]

Originally Posted by funjohnson

I can't believe how much lower the price is in Australia vs the US for these drop in packs. I wonder what contributes to that?

Besides Australia's much tighter integration with the Chinese economy, the fact that good quality true deep cycling lead banks are produced locally in the US, can still buy in every populated area as cheap as $1 / Ah @12V, for units that can last 8 years or more in daily use, makes for slower acceptance of new, much more expensive alternatives.

Because of high import tariffs into Australia on almost everything, and much thinner local manufacturing - population of under 25million - they have been paying more for poor quality AGM - Full River's considered a top value brand - for many decades, they hardly use better quality FLA at all!

Another factor, the crazy expensive insurance required for our US torts law regime, means only large well capitalized companies can safely become effective low-margin distributors of such HazMat-classified goods. The one-man outfits in the US like EPC are probably just one fatal-fire away from bankruptcy.

The much larger (relatively) off-grid outback campervan industry in Oz also helps, witness all the cool rig types just not available stateside.

Finally, since 99.99% of the worldwide LI battery industry came out of and has remained tightly intertwined with the Chinese military, the fact that Australian armed forces aren't too relevant to Chinese "national security" policy makes a difference I imagine.

The recent imposition of tariffs will very much add to uncertainties, but I have yet to see an impact at the level of the individual consumer.

______
The fact remains, European, Australian and South African battery markets are all very very different from North America

so, for such a sourcing thread as this to be more useful, IMO both the type of LFP battery and the consumer's location need to be specified in the title.

[KTP]

As I am currently using Lifeline AGM, price is a factor.

I can buy GPL-31XT 12V 125 amp-hr Lifeline AGM with one mouse click and free shipping for $400

They weight 74 pounds and at a 70% DoD are good for about 600 cycles. At 100 cycles per year that is 6 years of use. This would be about the maximum number of days that I would sail per year and draw down the bank 70% while motoring.

For that 70% DoD, if I have a large enough bank such that I am only drawing 15 amps per battery, then I can expect 455 minutes x 0.7 = 318 minutes of discharge. At an average voltage of 11.8V, this would be 938WH. Sixteen of these batteries (I only have eight right now) would give me 15kWh of useable energy at 70% DoD and a total draw on the 48V bank of 60amps. At that level of current to the motor controller, our boat will do about 4.3 knots in calm water. That would be a range of about 22nm at that speed, which is acceptable for how we plan to use our boat. In actual use we probably would be motor sailing and not even drawing 60 amps.

The problem is 16 lifeline batteries weight 74 pounds x 16 = 1184 pounds. Right now with eight batteries and our engine and diesel tank gone, we are sitting an inch or so higher out of the water than before, but if we add another eight we probably will be a little lower than with the engine. If we were to go with LFP the weight is cut in half or slightly better than half.

Cost is $400 x 16 = $6400 for the 15kWh useable bank with a life expectancy of 6 years = $1066 a year.

For LFP a 15kWh useable bank that would last 10 years (100 cycles a year still, but accounting for 3% battery aging per year) I would need to use about 16 of the Trojan Trillium 92AH batteries while only cycling them to 90% DoD. This would give me about 16kWh useable.

Weight would be 27 pounds x 16 = 432 pounds....really attractive...our boat would sit like 2 inches higher than with the diesel engine....would need to add rocks

Cost though....ouch. $850 x 16 = $13,600 + unknown shipping..say $400 for $14,000 total

$14,000 vs $6400.

Expensive yes, but I am super tempted to ditch the lead and go with the $14,000 option. Heck that is only 14 boat bucks

[newhaul]

Originally Posted by KTP

As I am currently using Lifeline AGM, price is a factor.

I can buy GPL-31XT 12V 125 amp-hr Lifeline AGM with one mouse click and free shipping for $400

They weight 74 pounds and at a 70% DoD are good for about 600 cycles. At 100 cycles per year that is 6 years of use. This would be about the maximum number of days that I would sail per year and draw down the bank 70% while motoring.

For that 70% DoD, if I have a large enough bank such that I am only drawing 15 amps per battery, then I can expect 455 minutes x 0.7 = 318 minutes of discharge. At an average voltage of 11.8V, this would be 938WH. Sixteen of these batteries (I only have eight right now) would give me 15kWh of useable energy at 70% DoD and a total draw on the 48V bank of 60amps. At that level of current to the motor controller, our boat will do about 4.3 knots in calm water. That would be a range of about 22nm at that speed, which is acceptable for how we plan to use our boat. In actual use we probably would be motor sailing and not even drawing 60 amps.

The problem is 16 lifeline batteries weight 74 pounds x 16 = 1184 pounds. Right now with eight batteries and our engine and diesel tank gone, we are sitting an inch or so higher out of the water than before, but if we add another eight we probably will be a little lower than with the engine. If we were to go with LFP the weight is cut in half or slightly better than half.

Cost is $400 x 16 = $6400 for the 15kWh useable bank with a life expectancy of 6 years = $1066 a year.

For LFP a 15kWh useable bank that would last 10 years (100 cycles a year still, but accounting for 3% battery aging per year) I would need to use about 16 of the Trojan Trillium 92AH batteries while only cycling them to 90% DoD. This would give me about 16kWh useable.

Weight would be 27 pounds x 16 = 432 pounds....really attractive...our boat would sit like 2 inches higher than with the diesel engine....would need to add rocks

Cost though....ouch. $850 x 16 = $13,600 + unknown shipping..say $400 for $14,000 total

$14,000 vs $6400.

Expensive yes, but I am super tempted to ditch the lead and go with the $14,000 option. Heck that is only 14 boat bucks

and by your calculations of 10 year life $1400 per year .
Now with sitting higher in the water you have less wetter surface so less drag/ friction when under power so less power needed ( battery range )
now with the data collected on longevity of Lfp likely you are looking at least 30 % low .
Which equates out to at least 13 years . ( so 1400 per year becomes 1076 per year)
( I bet they would last at least 15 years )

[KTP]

Originally Posted by newhaul

and by your calculations of 10 year life $1400 per year .
Now with sitting higher in the water you have less wetter surface so less drag/ friction when under power so less power needed ( battery range )
now with the data collected on longevity of Lfp likely you are looking at least 30 % low .
Which equates out to at least 13 years . ( so 1400 per year becomes 1076 per year)
( I bet they would last at least 15 years )

Yeah they probably would last 15 years, but by then we might be using uranium oxide batteries or something. Still, I do not have a firm grasp on what the aging per year is. If they age 3% per year irrespective of how many times you cycle them, then after 10 years you only have a 10Kwh bank essentially.

I am not trying to talk down the LFP though...for weight reasons and also for high current draw when needed (the 15kWh LFP bank could put out 5kW for 3 hours while the lead acid 15kWh bank would be lucky to do 5kW for 2 hours) I am all for LFP

If the Trojan Trillium 92ah battery had a writable CAN ID I would already have 16 on order. I am still not convinced that it doesn't even though a salesperson said it was a problem with V1 that you can't change the CAN ID so essentially only one battery can be on the CAN bus. I mean, that is something I would not have gotten wrong freshman year at GA tech.

[john61ct]

The calendar aging rate of isolated LFP stored isolated and at low enough SoC (but never approaching 10%)

comes down to the temperature they're stored at.

HUGE variation based on that alone.

Getting anywhere near 3% per year loss of capacity - that is **very** high - would require very high temperatures.

In conditions we humans would consider bearable, a properly stored LFP bank could sit for many decades and still be above 80% SoH, if that was your EoL spec.

And even being cycled daily, depending on how well cared for, with no catastrophic gear failure or human error "incidents" ten years would be a fraction of their potential lifespan.

Even at $7-8 per Ah at 12V, the cost **per year** would come out much lower than lead at 80% cheaper up front.

But of course the odds of such incidents occuring over such a long period can in some cases be very high, making the ROI in fact very risky.

So strictly economically, factors like high CAR, power density and energy density need to be important enough to justify the greater investment on their own.

[newhaul]

Originally Posted by KTP

Yeah they probably would last 15 years, but by then we might be using uranium oxide batteries or something. Still, I do not have a firm grasp on what the aging per year is. If they age 3% per year irrespective of how many times you cycle them, then after 10 years you only have a 10Kwh bank essentially.

I am not trying to talk down the LFP though...for weight reasons and also for high current draw when needed (the 15kWh LFP bank could put out 5kW for 3 hours while the lead acid 15kWh bank would be lucky to do 5kW for 2 hours) I am all for LFP

If the Trojan Trillium 92ah battery had a writable CAN ID I would already have 16 on order. I am still not convinced that it doesn't even though a salesperson said it was a problem with V1 that you can't change the CAN ID so essentially only one battery can be on the CAN bus. I mean, that is something I would not have gotten wrong freshman year at GA tech.

the 3% life loss is as I understand it shelf life not use life. The dynamics change as soon as the unit is cycled for the first time.
Also that is for the EV industry where the banks are regularly subjected to periods of draw and charge as high as 2C or even a bit more . On a boat you rarely ( even with electric propulsion ) will hit even .5C . Which considerably increases the survive life to well beyond 3,000 deep cycles .

[KTP]

The temperature of the battery vs life is a important consideration though (even for lead acid). Lifeline states that battery life is cut in half for every 10 degree C rise in temperature. LFP I am not sure but I do note that in the Trojan Trillium warranty fine print they say the 4 year/ 8 year warranty is void if the internal logger shows that the battery was used in a environment greater than 80 degrees F average temperature. This would seem to indicate that LFP lifetime is also greatly affected by temperature and might be a major consideration for someone sailing where even the water temperature is above 80 degrees F.

For us in the Northwest USA though, with the water at a balmy 50 degrees F most of the year, not really an issue.

[Steve Lavigne]

Originally Posted by KTP

If the Trojan Trillium 92ah battery had a writable CAN ID I would already have 16 on order. I am still not convinced that it doesn't even though a salesperson said it was a problem with V1 that you can't change the CAN ID so essentially only one battery can be on the CAN bus. I mean, that is something I would not have gotten wrong freshman year at GA tech.

Very strange. Their CAN doc demonstrates a method to address specific batteries to give control instructions, but does not document a way to change the default address.

https://www.trojanbattery.com/pdf/TRJN0531_TrilliumTechDoc_011419.pdf

Perhaps it is a documentation oversight rather than a true omission.

[newhaul]

Originally Posted by KTP

The temperature of the battery vs life is a important consideration though (even for lead acid). Lifeline states that battery life is cut in half for every 10 degree C rise in temperature. LFP I am not sure but I do note that in the Trojan Trillium warranty fine print they say the 4 year/ 8 year warranty is void if the internal logger shows that the battery was used in a environment greater than 80 degrees F average temperature. This would seem to indicate that LFP lifetime is also greatly affected by temperature and might be a major consideration for someone sailing where even the water temperature is above 80 degrees F.

For us in the Northwest USA though, with the water at a balmy 50 degrees F most of the year, not really an issue.

here is a snapshot of the specs for Lfp batteries
Says 104℉ storage and 140℉ discharge , and 113℉ charging
These are the max temps.

[KTP]

I mean sure, you can discharge the LFP when the battery temperature is 140 F but if you constantly keep the battery at that temperature I do not think you are gong to see 15 years of life (maybe not even 2 years!)

[newhaul]

Originally Posted by KTP

I mean sure, you can discharge the LFP when the battery temperature is 140 F but if you constantly keep the battery at that temperature I do not think you are gong to see 15 years of life (maybe not even 2 years!)

as I said those are maximums and the spec sheet also has minimums .
For instance the minimum charging of 32℉ battery temp is a hard rule you charge colder than that and you will cause irreparable damage .