LiFePO4

I am currently working through the monster Ca&S LFP battery thread; after a couple of weeks I am well over 1000 posts in.  That’s maybe a third of the total.

So that no one else has to summarize the info I am making a wiki page on it.  Bit of a mess right now, but here’s the takeaway for boondockers so far:  If we

1. start with balanced cells; and

2. charge to 13.8v; and

3. have sub-C (“fractional C”) charge/discharge rates

then we don’t need a balancing BMS.

Regular charge controllers with configurable setpoints can work fine,  Vabs would be 13.8v with a short a period as possible and “float” would be set to something lower than that (13.2 - 13.4v).  LFP batteries don’t need or use a real float so the lower voltage basically stops charging.

In a typical day the bank would charge to 100% SoC when the sun comes up, stop charging, drop under normal house loads to ~80% SoC  and hold there as long as the charger can support it.