Alarm going at end of overnight charging

[GoodKingW]

Hi

The last 2 nights I have charged through an Ohme charger (on Octopus overnight tariff 0030-0430) the alarm has gone off at 0430hrs or just after.

Anyone had experience of this?

I have charged for 20 minutes at a fast charge on the motorway in the interim and no issues

MG can book it in to check software but that will be 6 weeks plus
MG Assistance said try only charging to 80% but that's not ideal as I regularly need a full charge as an earlier model with 150 range.

Any thoughts / fixes welcome to save my sleep and that of neighbours...

 

[GoodKingW]

Not fully proven yet but I think this was caused by a door being slightly open

 

[Lovemyev]

12 volt battery issue ???.
The 12 volt battery is being charged when the car is charging via the inverter / traction battery of course.
But I am wondering if when the car quits charging, the system detects a low condition state on the 12 volt battery and triggers the alarm .
When the traction battery is charging, it will be receiving about 14 volts, when it stops charging at 4.30am is it detecting a drop to below 12 volts I wonder ?.
Long shot I know !.