SOC doesn't correspond to what is set up

[marcello]

Hi,
Sorry for the confusing title. In fact as you can see on the pics below, my cells are around 3.35v on average, which corresponds to a capacity between 70% and 80% according to what is set up in the bms config.
Then why the SOC is showing 99%?
Thanks

 

[sunshine_eggo]

Those values are used for the initial guess (BMS has no idea what the SoC is when first connected to the battery), and they are occasionally used to adjust the value. I don't know the rules for the adjustment, but I have seen it happen when a battery is allowed to sit for months.

Once you hit the "cell full voltage", the BMS says, "okay... I got it for sure now... we've hit 100%" and then it calculates SoC primarily by counting Ah in and out of the battery and calculating it against the programmed capacity.

The BMS maintains accuracy by regularly hitting the "cell full voltage" value. If not, accuracy will drift.

 

[mikefitz]

why the SOC is showing 99%?

The battery is almost fully charged, rested.

 

[marcello]

Those values are used for the initial guess (BMS has no idea what the SoC is when first connected to the battery), and they are occasionally used to adjust the value. I don't know the rules for the adjustment, but I have seen it happen when a battery is allowed to sit for months.

Once you hit the "cell full voltage", the BMS says, "okay... I got it for sure now... we've hit 100%" and then it calculates SoC primarily by counting Ah in and out of the battery and calculating it against the programmed capacity.

The BMS maintains accuracy by regularly hitting the "cell full voltage" value. If not, accuracy will drift.

Thank you very much for the explanation i understand now !

The battery is almost fully charged, rested.

Yes everything is fine