BMS Under Voltage

Been getting the above notification over the last two weeks, about once every couple of days. Does anyone know what it means and if I need to be doing something? The notification clears after 5 mins.

Is it somewhere cold?

Steve0898 I'm getting the same thing but it only started after upgrade to 3015.

Vestas it’s in a cupboard in bedroom so temp is above 12 degrees.

Update. I’ve just matched the notification times against the System Settings and it seems to occur when the battery drops to 0%. When the notification clears 5 mins later, it pushes the battery to 5% using grid energy. Now before the update in June (I think?), the battery would never go below 5%. Since the update it occasionally does.

What is the battery voltage when you get the notification?

4.25am Battery voltage is 45.32, batter watts 50. You see the battery goes to 0% at the end

Steve0898 what firmware version is your battery on?

3012 was fine for me, 3013 I had the same issue as you, 3015 has been fine for me.

Hook it says 4001 last updated 28/7/23. There used to be an option next to it to ‘check for new update’ but doesnt appear to be there anymore

Steve0898 so 4001 is the eon 'special' firmware that basically runs the 5.2 battery at 100% DOD.
There is a whole thing on this because e.on essentially sold them based on a misprinted (but surprisingly long lived) datasheet from GE which said the 5.2 packs were 100% usable (they are normally 80% so about 4kWh)
To get around having their a%% handed to them legally, they got their own firmware which really does push these to their extremes (like running a calibration each time) which results in it hitting the lower and upper voltage alarms.
Expect a reduced lifespan and more alarms as the packs get older/more cycles.

hoggy urgh! Typical E.on. I didn’t know that so thanks so much for the information. Assume there’s not anything I can about that…

hoggy interesting, as I didn't buy my kit through eon but all my paperwork states 5.2kWh useable capacity but I never got that, always the 80%. Never thought anything about it but maybe I should speak to my installer.

It’s all weird behaviour since the update. I’ve set the discharge buffer to 5% to try and support the battery life but it still goes down to 1%