Technical Support

Hello Sunsynk community,

I am operating a Sunsynk PolyTrack hybrid inverter + lithium battery system with a BMS and have noticed a discrepancy in SOC between the values ​​displayed from the battery BMS and the inverter, especially after deep discharge and fast charging cycles from the PV.

Practical Observations:

The SOC from the battery BMS is usually 5–10% higher/lower than the inverter.

After full charge, the discrepancy decreases but doesn't disappear completely.

There are no BMS communication errors.

I'm using a Sunsynk inverter with a lithium battery and have noticed that the SOC reading is unstable during daily use.

Specifically:

• SOC fluctuates rapidly in short periods.

• When the load changes, That's Not My Neighbor SOC jumps erratically.

• The battery still has charge, but the system reports it's nearly empty.

My current setup: