finlayson

FYI: If you have the EQS parked for a long time, then it will automatically recharge the 12V battery from the high-voltage battery, whenever the 12V battery's charge drops. (I have done this several times now in the 1.5 years that I've had my 2023 EQS SUV.) There should be no need to hook up the 12V battery to a charger.

jackonmbwheels

The HVB will recharge 12V only when vehicle is in operating mode (key position 1 or 2) or when connected on the charging port. Mine was in storage for 5 months and I was able to monitor dropping voltage from the distance with Mercedes Me.
No automated 12V charging did happen. May be they improved the SW for 23, mine is 22?

finlayson

No, that is not true - at least for the 2023 EQS 580 SUV. See my experience, reported here: https://mbworld.org/forums/eqs/86796...ml#post8796134

However, a few other people have reported not seeing their 12V battery getting recharged automatically from the high-voltage battery, so YMMV...

23-EQS580-SUV

The HVB only charge the 12V battery when the car is on. During it sleep the 12V will continue to drain. If you let the 12v battery drain too much upon starting the car all you dash lights will lid up and you will have to reset thing the window express up/down. This happened to my car during a front end ppf install over the weekend. I couldn't get the sunroof to close properly so had to take it into the dealership.

My brother went out of the country the same time with us, he left his brand new MDX sat for 2 months, battery was dead when he got back, he checks the voltage and it is showing 2.7V, Dealership replaced the battery under warranty.

There also a worry in the back of my mind that leaving the L1/L2 plugged in will caused something to happen like a fire. I even though about parking the EV outside. Better be safe than sorry, i guess. LOL

finlayson

Once again, this is not true - at least not for all EQSs. See my post above,

jackonmbwheels

IT is clear now that All EQS do not operate the same way. I am positive that my EQS sedan 2022 Edition 1 with SW 330.xxx does not recharge 12V battery automatically when in storage locked and no HVB charger connected. The MB me connect show 3 declining charge conditions over time. From fully charged, to acceptable charge and 4 months later LOW battery.
So for a model that function the way mine operate my recommendation are still valid.