MG4 battery always dead after holiday

[fnegroni]

So twice now I've gone on a 2 week holiday. When I return the car is dead. The 12v battery is completely dead.

I make sure I don't open the app and don't have any lights etc on. Surely this isn't right? AA guy says the battery is fine, it's just dead.

Did you replace the battery after the first time this happened?
Did you fully charge it on a trickle charger after it happened the first time? Even new batteries when supplied need a first full charge on a trickle charger.

 

[Ian Key]

You might need a software update as some cars don't seem to charge the 12V battery from the main battery unless the car is on or being charged. Mine will charge the 12V battery when the car is locked and not connected to a charger.

 

[Archev]

Anything plugged in to the OBDII port, e.g. black box insurance etc. ?

What about a continuously monitoring dashcam ? Mines has front and rear cameras. I’ve never noticed anything untoward but it is a 24/7 power drain.

 

[AdamMGEV]

Anything plugged in to the OBDII port, e.g. black box insurance etc. ?

nope, nothing

You might need a software update as some cars don't seem to charge the 12V battery from the main battery unless the car is on or being charged. Mine will charge the 12V battery when the car is locked and not connected to a charger.

Really... I didnt think it would do it unless it's in ready mode or plugged in.

What about a continuously monitoring dashcam ? Mines has front and rear cameras. I’ve never noticed anything untoward but it is a 24/7 power drain.

No nothing extra installed on the car and no USB plugged in apart from the usb cable for the phone, but obviously nothing plugged into the cable whilst on holiday.

 

[decrep]

I just found this in the manual.

Note: It is recommended to set the power mode to
READY for more than half an hour every week to
help extend the service life of the battery.
When the vehicle will not be used for an extended period (more
than 1 month), it is recommended to disconnect the
battery negative terminal clamping pile head. Make
sure that the vehicle power system has been turned
off before connecting or disconnecting the negative
battery cable.

 

[Fads54]

So twice now I've gone on a 2 week holiday. When I return the car is dead. The 12V battery is completely dead.

I make sure I don't open the app and don't have any lights etc on. Surely this isn't right? AA guy says the battery is fine, it's just dead.

I had a similar problem with my ZS Trophy LR. Turns out the audio system was still on in the background and drained the 12V battery. MG dealership investigated and fixed the problem. I’m away for 2 weeks at the moment and car is at the airport. Just in case I’ve bought a booster battery pack and keep it in the car cabin. Hopefully won’t need it ?

 

[yellowking]

Left mine for 5 weeks this year. I won't say it started up on my return but drove as normal no issues at all.