Guru
Joined: 13/10/2014
Location: AustraliaPosts: 2199
| Posted: 03:24am 18 Dec 2023 |
Hi Aaron, yes looks like the same factory for the BMS.
The inbuilt BMS 30ma passive balancer would take forever, the 1A external Active balancer is working pretty quickly. I could have turned off the inbuilt passive balancer but instead set it to only work at the float charged voltage.
Apart from overcharging, aggressive charge and discharge current and running it flat, the other way to degrade a LiFePO4 cell is to leave it sit "near" 100% charge for an extended length of time, UNLESS it's being cycle charged and discharged each day, which is what LiFePO4 was made for. They start to degrade sitting above 70%, obviously for many months or more. When you look at the chemistry and the latest scans of the efficiency degradation pathways you tend to think about it a little more, it appears to be an ongoing evolution in best practice for longer LiFePO4 battery life.
In my case I'm holding the reserved banks at 90% as they get a cycle every 3 days, the data on the level of cell degradation from 12 months of near 100% is not nice to see if you have cells of suspect quality, which is unknown in my case. So I have erred on the side of caution from day one, and it has been two years so there will likely be some age related drop as well, I will soon find out when I get around to testing.
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