12 Volt Battery Issue.

What I Drive
2023 S90 Ultimate
Hi Everyone,

just wondering if anyone else is experiencing this or if anyone has some advice.

my 2023 S90 sits in a heated garage for some long periods of time and during that time the 12 volt battery used to start the vehicle drops from 100% charge to 76% charge. I was told by Volvo service to ensure my doors were locked, they were.
now this happened to me also over the Christmas holiday and the car completely shut down to the point where I had to use the emergency key to get into the vehicle and then boost it to start and then the vehicle gave me a "12 volt critical charging fault" stop vehicle and contact Volvo service. I did that.

Now, since this is a mild hybrid and the 48 volt battery system is used as electric assist as per all of Volvo's literature to maintain the vehicle systems other than the start function of the engine, then the 12 volt battery should no be affected at all.

the vehicle is currently fully charged and is on a maintaining charger, again, locked and in a heated garage.

any input and or information would be greatly appreciated.

Thank you