MPPT Solar Charge Controllers state of charge

[jacobberke]

Good evening from Maryland!

I am confused, I have 2 200Ah Powerurus LFP batteries and it's connected in series to make 24V. My All to 30A charge controller does not indicate the battery cell state of charge correctly. It shows 3 bars out of 4 when it's 100% according to battery BMS. This is the same situation on my MPP Solar 2024 All in one unit, that's why I bought this separate charge controller. Any ideas?

 

[sunshine_eggo]

Except in rare cases where a battery has been at rest for about 24 hours, voltage based SoC values are completely worthless. For LFP, the tend to only need to rest for a short period.

It's likely lead-acid voltage based, and you should ignore it.