B300S Battery at 25% - then a minute later at 0%

Hi, Have AC500 + 2 X B300S

I use 1 battery alternately

1 battery even with no load other than fridge freezer using about 300 watts a day, will suddenly lose the remaining 20% to 25% in a matter of seconds

Anybody got a fix for my problem?

Thanks in advance

Grantham, Lincolnshire, UK

Have you tried to calibrate the SOC?
First discharge the machine to 0%, then charge it to 100% via AC. During this time it needs to be charged continuously, with no loaded. Please try to cycle twice.

If the situation still does not improve, please provide your AC500 and B300 serial numbers and our @BLUETTI_CARE team will assist you.