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Battery SOC value decreases but never increases

Category: Hardware
Product Number: MAX17205

We have implemented a design using the 17205 battery monitor with a 2S2P Li-Ion battery.

I have noticed that the state of charge value will decrease from the initially read value, and then I let the device consume some battery power, SOC changes, then when charging, the SOC value never increases even though the battery charges. Battery charger status seems correct.

I have the same issue regardless of using the 17205 in our design or with the MAX17205X EV Kit, so I believe my I2C calls are good.

Our design has DC power going to a MPS MP2759A charger. We've implemented digital controls to disable charging (i.e., if temperature gets too high) and/or disconnect the battery (so we can implement a firmware shutdown sequence). Is there something I need to do differently here to get SOC working?

Thank you!