K2 battery endurance

On Sunday, May 31, 2020 at 4:15:11 PM UTC+2, wrote:
On Saturday, May 30, 2020 at 5:47:01 PM UTC-4, kinsell wrote:
Testing is always good, but John has a very reasonable suspicion the
problem was due to cold soaking the batteries. LFP's really don't like
the cold, and can even be damaged if charged below freezing. Maybe he
had a temporary loss of capacity that wouldn't show up under room temp
testing.

LFPs don't like to be charged while cold (below the freezing point of water is the rule of thumb, even though they are not made of water). But they discharge just fine while (reasonably) cold. Their capacity while cold doesn't suffer anything like the way SLAs capacity does.

FYI the capacity does still suffer somewhat, -20% at -10c, http://liionbms.com/pdf/kokam/SLPB10...0Ah%20Nano.pdf

On 5/31/20 9:03 AM, wrote:
On Sunday, May 31, 2020 at 4:15:11 PM UTC+2, wrote:
On Saturday, May 30, 2020 at 5:47:01 PM UTC-4, kinsell wrote:
Testing is always good, but John has a very reasonable suspicion the
problem was due to cold soaking the batteries. LFP's really don't like
the cold, and can even be damaged if charged below freezing. Maybe he
had a temporary loss of capacity that wouldn't show up under room temp
testing.

LFPs don't like to be charged while cold (below the freezing point of water is the rule of thumb, even though they are not made of water). But they discharge just fine while (reasonably) cold. Their capacity while cold doesn't suffer anything like the way SLAs capacity does.

FYI the capacity does still suffer somewhat, -20% at -10c, http://liionbms.com/pdf/kokam/SLPB10...0Ah%20Nano.pdf


You grabbed the data sheet for a lithium-polymer battery, which is quite
different than the LFP that John would have been using.

http://kokam.com/data/Kokam_Cell_Bro...19847c0b83f2f5

Even with the correct data sheet, that would have been for a brand new
battery, no cell balancing issues.