Battery magically gained power overnight?

My battery have seemingly went from 5% to 20% in the span of 25 minutes and it doesnt look like it was charged by the grid - does anyone have any idea what is going on here?

arczi19 it would be helpful to know what sort of system you have, and how old it is.
It might be the battery rebalancing the cells, which it can do when it's idle at a low state of charge. Though that is quite a sizeable gain . Do you regularly run the battery over it's full range? If not, the BMS can lose track of the SoC.

DD Apologies, very good point. Its a gen3 inverter 3.6kWh coupled with 9.5kWh battery. I've had it for almost 2 months now. I typically charge up my battery to 100% at night and then throughout the day there wold be a mixture of home energy use and exporting and it would normally finish the day at about 20%.

arczi19 See also the end of this thread for more on rebalancing:
https://community.givenergy.cloud/d/4066-giv-energy-battery-charge-to-capacity

If you don't already have it, I can recommend the 3rd-party android inverter monitor app: https://givenergymonitor.wixsite.com/tutorials Among other things, it can show the individual cell voltages. I know the voltages should be close, but unfortunately don't really know how close is close. I guess the balancing is intended to try to keep them aligned.

DD Thank you, thats very helpful!

DD

Among other things, it can show the individual cell voltages. I know the voltages should be close, but unfortunately don't really know how close is close. I guess the balancing is intended to try to keep them aligned.

I don't think anyone but GE know that part. My none GE packs kick in the passive balancers when alignment is more the 30mV out. I also have a no name (read as "cheap") active balancer I keep meaning to fit that is fixed at 20mV so I'd imagine GE is somewhere around that kind of imbalance.

For further reference my 9 year old Pylontech stack seems to try to keep them no more than 30mV apart as well, although it hardly ever runs the balancer as despite their age I struggle to push them more than 7mV out unless I'm really hammering them to completely 100% or 0%.