Battery oscillating around set charge level when EV is charging overnight

Hi all,
Have a Givenergy 9.5kWh battery and a Zappi charger on an Octopus Go Tariff.
During the off-peak hours (00:30 to 04:30) I have the Zappi set to charge the car, and the battery set to charge to 20%.

That means anything over 20% will be fed to the EV first, and then the EV will charge off the mains while the battery should be left with 20% capacity.

It more or less works, but I've noticed that instead of hitting 20% and shutting off, the battery will switch between discharging down to 19% and then charging back up to 21%. It does this at the full 3.5kw output power.

I'm a little worried about the wear on the battery in the long term. I know these things are hardy but it's gonna be going through this cycle several nights a week.

Anyone got any tips or a workaround?

It's a known bug. As an interim fix, my standalone version of PALM software (not the HA version) puts the battery"on hold" until the end of the off-peak period once it hits the target. www.github.com/salewis38/palm

Ah ok thanks. Tbh if it's a known bug then I'd be inclined to forget about it and assume it'll be sorted in the future.

WA144 all of that pushing and shoving each night can get expensive, even at off-peak rates.

WA144, my system used to do that but not to the same high power levels.

Newer firmware (already on official release) has fixed this issue, so I do not have that problem any more, even when charging the EV through my Zappi.

What inverter model have you got with the 9.5 kWh battery?

Simon_C I understand that the issue is fixed in the latest hybrid inverter firmware but the corresponding AC3 firmware is still in work.