HI:
I used BQ40Z50-R2 this chip with a 4-string lithium iron phosphate battery, and found that the SOC offset was large , up to 27% in the worst case.
Here are some things I do:
1: Use the charging and discharging data of the LFP match the chemical ID. The feedback is as follows.
2: The chip firmware is configured. The firmware parameters are as follows。
link：pan.baidu.com/.../1GZGNpwxU56vDR6HFWP3I7Q
password：1111
3: Three cycles of full charge discharge were tested. Finally, it was found that when RSOC=0%, the battery could continue to discharge and release 27% of the battery capacity.
4: The LFP data is as follows:
Ask for help:
1. How to optimize the configuration to improve the accuracy of SOC calculation?
2: Whether more chemical id need to be verified.
3: Is there any other method to optimize the coulometer to calculate LFP SOC?
Looking forward to your reply，thanks!
