question

AdrianC avatar image

Not reaching SOC limit

My system uses the ESS assistant and would normally discharge to the "minimum" or "active" SOC limit. Currently, this is at 30% for both. However, in the last month or so, the system is only reaching 38%, even if I switch off-grid. It seems to be switching at the sustain voltage (50v). The battery seems to be healthy and it's BMS is not giving any error. Also, the battery is charged to 100% every day. I even kept the batteries charged for 3 days but when trying it this morning it switches again at 38%.

Is this a setting issue (which has not been changed) or a battery issue? Or should I be checking something else?

SOCbattery system voltage
10 |3000 characters needed characters left characters exceeded

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

1 Answer
Daniël Boekel (Victron Energy Staff) avatar image
Daniël Boekel (Victron Energy Staff) answered ·

Hi @AdrianC

Most probably: your discharge voltage limits in the Multi (ESS assistant)

This thus can be a sign of your battery loosing capacity, so you might want to discharge it less deep to prevent more degradation.

1 comment Share
10 |3000 characters needed characters left characters exceeded

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

Thank you @Daniël Boekel (Victron Energy Staff) , I will check out the battery as it is only 11 months old lithium battery with an average DOD of only 50%. It should not be degraded at this point with that type of usage.