Lithium costs: comparison and sanity check?

[ranger58sb]

So... Firefly...

Hmmm... some of this seems to good to be true. And perhaps besmirched by a 2010 Chapter 7 thing...

Anyway, for interested readers:
http://www.bruceschwab.com/uploads/2...y-handout2.pdf
http://www.bruceschwab.com/uploads/t...-lead-acid.pdf
http://www.bruceschwab.com/uploads/f...pot-2-2014.pdf

My quickie comparison looks like this (although it looks much better in the spreadsheet; it's really 4 columns, 3 with numbers and one with comments):

Firefly Odyssey Lifeline

116 100 220 Ah (20-hr rate)

3 3 4 To-be-installed bank size; limited by space

348 300 440 To-be-installed bank size (Ah)

800 1370 925 MCA (32°F)

600 1150 750 CCA (0°F)

225 205 492 RC Mins@25A

3600 650 1000 Designed cycle life, to 50% DoD; Odyssey estimate is eyeballed from their graph)

1000 400 550 Designed cycle life, to 80% DoD

75 77.8 66 Weight (each, lbs)

$425 $328 $310 Prices (not including freight; Firefly is from the Bruce Schwab website)

$1,275 $984 $1,240 Bank cost (not including freight)

$0.354 $1.514 $1.240 Cost/cycle (to 50% DoD)
$1.275 $2.460 $2.255 Cost/cycle (to 80% DoD)

The actual batteries in question here are:
- Firefly Oasis Carbon-Foam 12V AGMs
- Odyssey 31M-PC2150 12V AGMs (same as currently installed in our main banks)
- Lifeline GPL-4CT 6V Golf Cart AGMs

The Firefly cycles to 50% (3600!) and 80% (1000!) DoD -- and resultant cost/cycle outcomes for the Firefly batteries -- are the most surprising. Assuming my math is correct.

-Chris

[Kim Klaka]

I replaced agm house battery with lithium a year ago. Cost about
15% more than good agm, A about one third the weight. Trick is to compRe AVAILble capacity. Agm availBle is (80-50%) rated amphours whilst lithium is (100-20%). All numbers approximTe

[roland stockham]

If you are looking for a well established alternative to lead acid try looking at the NiCad's used for backup power in things like emergency power. Much cheaper, well established, very high charge/discharge rates don't mind being run down to 90% and stored flat, 20yr+ lifespan. Bigger than led acids for same capacity and only available in the larger sizes. Just a thought.

[nimblemotors]

Firefly went bankrupt, didn't think they are still produced.

China Aviation (CALB) is one of the few remaining LiFe cell makers,
and without competition, they have increased prices.
The good news is they stock these cells in southern califonria,
so less monkey business. Seems around $2500 for 360ah 12v.

[Maine Sail]

Originally Posted by nimblemotors

Firefly went bankrupt, didn't think they are still produced.

China Aviation (CALB) is one of the few remaining LiFe cell makers,
and without competition, they have increased prices.
The good news is they stock these cells in southern califonria,
so less monkey business. Seems around $2500 for 360ah 12v.

Firefly was bought and are still very much in business. Sinopoy and Hi Power can also be found stocked in the US.

[nimblemotors]

Calb CA100AH LiFePO4 Cells Electric Vehicle Battery EV | eBay

Looks like a good deal, particularly if you can drive over and pick them up in Texas. $115 for new 100AH CALB cells.

I googled Firefly batteries, didn't find anywhere they are for sale, except Schwab, no links to buy or how to on the firefly website.

I recall HiPower is not making cells anymore, maybe just not selling to the US, they were always known for being poor quality, I wouldn't buy them.

[senormechanico]

Have you got anything to back up that "poor quality" claim?



I've got a 200 aH HiPower Lithium Iron Phosphate bank that's several years old and working just like the day I installed them.
I've not plugged into shore power since I installed them and the refrigerator/freezer has run almost continuously since then, powered by solar.
I also run the inverter to make hot water.

I love my Lithiums.

[ranger58sb]

Originally Posted by roland stockham

If you are looking for a well established alternative to lead acid try looking at the NiCad's used for backup power in things like emergency power. Much cheaper, well established, very high charge/discharge rates don't mind being run down to 90% and stored flat, 20yr+ lifespan. Bigger than led acids for same capacity and only available in the larger sizes. Just a thought.

Thanks. Useful info, but in our case, for this issue, size (space) matters!

But also I'm happy to rely on Maine Sail's advice to just stick with AGMs for our application. When the guru speaks...

-Chris

[ranger58sb]

Originally Posted by Maine Sail

Firefly was bought and are still very much in business. Sinopoy and Hi Power can also be found stocked in the US.

Like Nimble, I saw the info on the Schwab site and assumed Firefly is in business and healthy. Didn't actually look for "add to cart" links, since I'm still in the planning stages, but the $425 price tag (per each) was easily visible.

But can it really be that carbon-foam technology increases cycle life 3.5x more than Lifeline's deep cycle gold cart batteries? 3600 cycles to 50% DoD, versus Lifeline's 1000 cycles? Or 5.5x more than Odyssey's G31s? 3600 cycles compared to ~650?

Really?

My first take, after seeing the Firefly G31s vs. Lifeline GCs comparison, is...

Without (too much) regard to cost/cycle, my space issues are such that I can fit either 3x G31s or 4x GCs into the area where my starboard bank lives... but I can only fit 4x G31s in the space where my port bank lives (no room for 4x GCs).

Given that I could bring my starboard bank up to 440 Ah total capacity, and that would mean I could use 220 Ah (to 50% DoD) before charging again (compared to 348 Ah total, and 174 Ah at 50% DoD)... the 6V GC solution for the starboard bank would still be slightly better for us, even if more expensive in the long run. Our starboard bank takes a big hit servicing the electronics suite...

In any case, I can get Lifeline batteries just up the street, so not much in the way of transportation costs.

And then maybe the Firefly G31s to eventually replace our port bank (i.e., when necessary, ideally another 5 years down the road ) would be at least a slight upgrade in capacity and a huge upgrade in cycle life.

If that 3600 cycles could be right.

But I'm still thinking.

-Chris

[goboatingnow]

just some sanity here, I really suspect people claiming they are recharging to 100% SOC on Li, are coding themselves.

LA is abou 50-60% in reality, Li, is likely to be about 60-70%. LI efficiency is about energy density not realisable energy. I suspect in practice actual realisable figures from a good LA bank and a Li bank are not much different, since most large formats are not recharged to 100%, nor taken below 20%, Hence you are looking at a 10-15% gain over LA in real practical terms

Boats in general are not great candidates as they are not ' that " weight sensitive

Li has some other good characteristics, like flat discharge curve and insensitivity to partial charge, These are greet characteristics for certain types of boat users, especially heavy users, that are away from shore power etc

[Maine Sail]

Originally Posted by ranger42c

Like Nimble, I saw the info on the Schwab site and assumed Firefly is in business and healthy. Didn't actually look for "add to cart" links, since I'm still in the planning stages, but the $425 price tag (per each) was easily visible.

But can it really be that carbon-foam technology increases cycle life 3.5x more than Lifeline's deep cycle gold cart batteries? 3600 cycles to 50% DoD, versus Lifeline's 1000 cycles? Or 5.5x more than Odyssey's G31s? 3600 cycles compared to ~650?

Really?

My first take, after seeing the Firefly G31s vs. Lifeline GCs comparison, is...

Without (too much) regard to cost/cycle, my space issues are such that I can fit either 3x G31s or 4x GCs into the area where my starboard bank lives... but I can only fit 4x G31s in the space where my port bank lives (no room for 4x GCs).

Given that I could bring my starboard bank up to 440 Ah total capacity, and that would mean I could use 220 Ah (to 50% DoD) before charging again (compared to 348 Ah total, and 174 Ah at 50% DoD)... the 6V GC solution for the starboard bank would still be slightly better for us, even if more expensive in the long run. Our starboard bank takes a big hit servicing the electronics suite...

In any case, I can get Lifeline batteries just up the street, so not much in the way of transportation costs.

And then maybe the Firefly G31s to eventually replace our port bank (i.e., when necessary, ideally another 5 years down the road ) would be at least a slight upgrade in capacity and a huge upgrade in cycle life.

If that 3600 cycles could be right.

But I'm still thinking.

-Chris

Chris,

Anyone thinking they will get "lab cycles" in the real wold is living in a fairy tale... In the "lab" Firefly has demonstrated this, as has Lifeline with their data & Odyssey etc..

It's won't likely happen in the real world.. Look for an article dealing PSOC operation of AGM batteries in the next month or so....

[Maine Sail]

Originally Posted by goboatingnow

just some sanity here, I really suspect people claiming they are recharging to 100% SOC on Li, are coding themselves.

LA is abou 50-60% in reality, Li, is likely to be about 60-70%. LI efficiency is about energy density not realisable energy. I suspect in practice actual realisable figures from a good LA bank and a Li bank are not much different, since most large formats are not recharged to 100%, nor taken below 20%, Hence you are looking at a 10-15% gain over LA in real practical terms

Boats in general are not great candidates as they are not ' that " weight sensitive

Li has some other good characteristics, like flat discharge curve and insensitivity to partial charge, These are greet characteristics for certain types of boat users, especially heavy users, that are away from shore power etc

Dave we are using 290 - 320 Ah's, on average, before recharging & resetting the Ah counter and doing it all over again. This is between 70 & 80% of our banks rated capacity...The bank is 400Ah.... Been doing this regularly and never once come close to the LV threshold..... With our old LA bank we were only able to realize about 30% - 35% of the capacity when off cruising.

[goboatingnow]

Originally Posted by Maine Sail

Dave we are using 290 - 320 Ah's, on average, before recharging & resetting the Ah counter and doing it all over again. This is between 70 & 80% of our banks rated capacity...The bank is 400Ah.... Been doing this regularly and never once come close to the LV threshold..... With our old LA bank we were only able to realize about 30% - 35% of the capacity when off cruising.

in terms of mid range use, or partial recharge I agree. The efficiency extracted from LI subjected to partial charges is much better then LA. ( because of course LA suffers from not receiving a 100% recharge.


From a bank resizing basis , taking averages of capacity and consumers and generators . I would again say that making simple assumptions of 80% over 50% etc are a bit just that.

BY THE WAY , I would argue that if you are extracting 80% without hitting LV, either the bank is bigger then you think ( not unusual in large prismatics) or the LV is too low.

[Maine Sail]

Originally Posted by goboatingnow

in terms of mid range use, or partial recharge I agree. The efficiency extracted from LI subjected to partial charges is much better then LA. ( because of course LA suffers from not receiving a 100% recharge.


From a bank resizing basis , taking averages of capacity and consumers and generators . I would again say that making simple assumptions of 80% over 50% etc are a bit just that.

BY THE WAY , I would argue that if you are extracting 80% without hitting LV, either the bank is bigger then you think ( not unusual in large prismatics) or the LV is too low.

The LVC (warning level) is set at 2.9V / 11.6V and emergency cut is set at lowest cell 2.6V...

I recently ran a series of tests on a CALB SE100AHA 4S pack.

Charged to 14.0V and current tapered to 5A

Initial Capacity 101.2 Ah's @ .25C Discharge

Discharged with a 12.400V cut off floor (3.1VPC) = 87.02 Ah's delivered

At a low of 12.4V / 3.1VPC and a .25C load the bank delivered approx 86% of its capacity and was still above the LVC (2.9V) and well above CALB's 2.5V absolute cut off point or the BMS's absolute cut off of 2.6VPC......

[ranger58sb]

Originally Posted by Maine Sail

Chris,

Anyone thinking they will get "lab cycles" in the real wold is living in a fairy tale... In the "lab" Firefly has demonstrated this, as has Lifeline with their data & Odyssey etc..

It's won't likely happen in the real world.. Look for an article dealing PSOC operation of AGM batteries in the next month or so....

Oh, sure, I get that, always realized that the lab numbers are a) bragging, and b) a simple way to generally (roughly) compare products.

Still, even if Firefly and Lifeline numbers in the real world are only half of what they spec with lab numbers... it still means the Firefly folks are saying they're design life is 3.6x more cycles (to 50% DoD) than Lifeline's.

Can that be for real? Can carbon-foam really be that much magic?

I'll watch for that article!

-Chris