RJXZS - unreliable SOC when system is idling

[pazdzierzz]

What

Correction of battery SOC during longer idles.

Why

RJXZS does not care about total pack voltage and temperature when estimating SOC. Hall sensor also does not detect small parasitic battery drain caused by inverter. That causes a situation when battery voltage is dropping with SOC freezed (estimated 0,01V drop per 3 hours with Sofar inverter). After a while that causes battery contactors to open because of cell discharge limit protection.

How

BMS calculates SOC (battery capacity percentage) based on two values: battery pack capacity and battery usage capacity

SOC = (bp capacity-bp usage capacity)/bp capacity * 100%

Maybe there is a way to create a lookup table of cell voltages for Lily - when total voltage of battery will be not in line with voltage estimated SOC , Lily will send battery usage capacity correction to BMS.

Some provisional table created with ChatGPT (surely have to be verified)

CAN ID for BMS to receive battery used capacity: