Top balancing should i use a bms

[SilverbackMP]

Right after commissioning. ?


But I think I only took them 3.60. But let them settle several times and recharged.

8 batteries parallel cause I have two bench chargers/testers (both the Zketech 5v40A units). True EV grade CALB cells. Grade B might behave differently.

Best I could do with time running out and with with no shore power and using a mix of the big generator and series of harbor freight shitboxes. And needing to do eight 16s batteries. So 128 cells.

 

[toms]

I think you meant that as tail current, not an actual charge rate?

I measured it, and my 280Ah cells took on another 400mAh between 14A and 0A... Tapered FAST.

Yes, tail current. Maximum charging current is typically 1C.

BUT... this is impossible to determine based on voltage.

Yes, that is exactly my point - so why connect cells in parallel before you know they are at the same SOC.

Back in 2010, weren't "they" still charging to 4.2 and discharging to 2?

Yes, that was a different argument, one that was settled much more rapidly - under those conditions a couple of years and the cells were toast.

There was one rather vocal expert in Australia that sold cell balancers that bypassed at 3.65V. He must have been responsible for thousands of cell failures but because he got on the internet early and had a lot of customers it took many years to overcome the notion that holding a LiFePO4 cell would shorten its lifespan.