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SOH now what is this???---->storage... i have more questions than answers
#11
Gents, i thank you for your answers.

Yes a bit of a late replay, i wanted to read more.

If I understand it correctly the leaf cells (if not mistreated) could be used up to even 15% soh?
If this is true, than it will be a better deal than with the Winston/Thunder-sky or the ones from BLS both incl the advised bms.

For a total of 20kwh storage:
Second handed leaf: 4700E incl batrium. (toke a swing at the import tax ~500E)
New Winston cells: 12.800E
New BLS cells: 5600E.
Those prices are not including wires fuses cabinet inverter ect, just storage with bms.

But how far can you go with LiFePo4 cells in terms of SOH?
Or with the Leaf cells?
Can anyone shed some light on this or own experience?

Thanks in advance for your answers, best Igor
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#12
Mnay LiFePo4 have datasheets below 60 or even down to 40. Mine have charts down to 40%. So in current pace the AGE Will degrade faster than cycling for me....
NOTE! My links supplied in this message may be affiliated with Ebay and by clicking on them you agree on the terms.
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Current: 10kW Mpp Hybrid | 4kW PIP4048 | 2x PCM60x | 100kWh LiFePo4 | 20kWh 14s 18650 |  66*260W Poly | ABB S3 and S5 Trip breakers
Upcoming: 14S 18650~30kWh
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#13
At Daromer,
I found a lot of bullshit about age, really a lot, but no facts or stats.
I think i understand your situation.
But you sell and gain every day, how does age count for your cells?
Is your problem not more the cycle life????

But Oke

For example:
https://www.abcnissan.com/blog/2018/octo...o%20happen.

Especially the part in "cold" conditions.....if reading carefully you will find what they all say:
Cold climates yield a longer battery life, but a shorter driving range.....

But we don't use 85kw in one hour, except in our cars....24kwh would be empty in 45 minutes on the highway not city!
24kwh i would not even use in one day(the ev's and induction cooking is a different story)
I understand the hot and cold climate part, but aging is new for me.
I am planning to store them in a "basement type like conditions" like my wine ~15 to 20c max whole year around....

So go big or go home hold no ground?
Please tell me more.
ANY info is appreciated, thanks in advance, with best regards Igor
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#14
Age is like everything else
In some tests they state you loose up to 6% of the total capacity per year. This at stored temperature at 20C and i think it was 80% SOC... But dont take me on those numbers 100% since it was some weeks since i read it last time...

For instance i got like 2500 cells that was NEW-old stock. They were 6 years old and testing yielded a loss of around 5--10% in total. They were all stored in less than 15C and where at 40% SOC.... So with those to you can calculate. Higher SOC and higher temp = more loss per year. Easy 6% loss per year in capacity just due to age for many of the users here

I dont think the cycle count is what kill my cells. Note that i cycle roughly 10% of the total capacity per day at most. Lets say you need 60% or more to count as a "cycle" when we talk from the datasheet. That means i cycle roughly 365/6 = 60 Cycles per year. IF we translate that very very roughly to losses in capacity thats like uhm.. Fraction of a % Smile Note that at 60% cycle my cells are guaranteed 5000 cycles before they have lost 40% of their capacity. So if we take those number i loose around
83 years before that happen or 0.7% capacity loss per year.
And 0.7% loss per year cycling is less than lost due to age Wink

Note that i dont cycle more than 10 months out from 12. Also note that my average temperature for the cells are around 12-13C if we flatten it all year around Smile

Hope that give some input and why i have done as i have and why i reason like i do. I have sat down calculated and looked through how it works.

Go big or atleast big enough is important!
100kwh-hunter likes this post
NOTE! My links supplied in this message may be affiliated with Ebay and by clicking on them you agree on the terms.
YouTube / Forum system setup / My webpage  Diy Tech & Repairs

Current: 10kW Mpp Hybrid | 4kW PIP4048 | 2x PCM60x | 100kWh LiFePo4 | 20kWh 14s 18650 |  66*260W Poly | ABB S3 and S5 Trip breakers
Upcoming: 14S 18650~30kWh
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