Here is a good comparison chart of lifepo4 cells for those who might want to make their own battery.
I ordered a JKBMS and will probably be getting some EVE cells soon.
https://www.gobelpower.com/battery_cell_database_ap14.html
Larry
Thank you Larry ! That is a good sheet !
Surprising on how the specs are so different on some cells from the same manufacturer.
Larry
Quote from: ClassicCrazy on June 04, 2024, 07:59:36 PMSurprising on how the specs are so different on some cells from the same manufacturer.
Larry
Yes. Except for the 3.2V part I think.
It's a neat charge for sure !
boB
Quote from: ClassicCrazy on June 04, 2024, 07:59:36 PMSurprising on how the specs are so different on some cells from the same manufacturer.
Larry
I always thought that 2.5V was the absolute lowest a LiFePO4 cell should ever drop to. Surprised to see from the chart, some manufacturers have 2.0V. There's not much left in a LiFePO4 in that last 1/2 volt, so probably best for a BMS to cut off at 2.5V (or even higher.)
Quote from: Hockey on June 20, 2024, 10:38:10 AMQuote from: ClassicCrazy on June 04, 2024, 07:59:36 PMSurprising on how the specs are so different on some cells from the same manufacturer.
Larry
I always thought that 2.5V was the absolute lowest a LiFePO4 cell should ever drop to. Surprised to see from the chart, some manufacturers have 2.0V. There's not much left in a LiFePO4 in that last 1/2 volt, so probably best for a BMS to cut off at 2.5V (or even higher.)
probably is more like the kill the cell stage.
But I have some Calb cells that I thought I ruined. First lithium I got when I didn't know anything and took some poor advice on them, and also didn't have a bms because at the time there was not really much available like these days and what was there expensive. They sat around uncharged for years and I had thought when I gave up on them some cells were really at bad stage. But last year I got them out , put some charge in each one, then put the pack back together and they charged up . I have not load tested them yet but plan to see what they can do. I have heard other people say they have brought dead lithiums back by some repeated chargings but forget the details.
Hopefully I am lucky and now I know much much more about LiFePO4
Larry
Hey Larry Calbs are great I know I have been using them since 2018.
Did so with out bms for a long time.
Mine also sat for an about a year purchased in 2017.
Got one of those battery resistance meter(don't know if they are any good) recently and turns out they are in really good shape.
I tested against smaller similar cells that would have failed .Not an accurate test but at least I know from daily use they still seem new after 6 plus years.