Dual JBD 24V LifePO4, different currents

[edgecrusher]

I have 2x24V (8s) batteries, 75ah each
Both are on JBD BMS', monitored and historized data in home assistant. I have also made the settings on both JBD's identical, and confirmed that at rest (no load connected) the current meter reads 0.

I have them wired in parallel with the same length wiring to my inverter, with the + and - on separate ends of the battery.

Although I would accept some difference over time, the %SOC and current push/pull varies by ~30% between the batteries (leaning to more load on JBD Pack1, which is about 3 months older than the newer pack). The individual cell voltages are extremely similar across both batteries, and both have either active balancers (currently unplugged), in addition to the crappy passive balancing from the BMS above 3.4V.

I can provide tons of data if needed, but any early ideas on the potential issue (or is there one?).

End of the day, one battery is reading at 8%, and the other at 29%. I charge them both to ~95% (or 28V) nightly.

Could just be non-calibrated current shunt in one of the batteries?

 

[edgecrusher]

I guess I should have posted this in the BMS forum... Mods, you can delete this one, and I'll post over there.

 

[740GLE]

pics of the set up?

Are you wiring batteries to a bus bar then inverter to the bus bar? Or are you double stacking lugs on the inverter?

 

[edgecrusher]

Cross post to the BMS forum now (link here). Will post there to try to combine.