MGS5 12V battery dead

[Shwd mae]

Has anyone else had a problem with the 12V battery becoming drained overnight? I returned my first MGS5 due to this problem and today I have had exactly the same problem with my replacement MGS5, arghhhhh.

 

[Ian Key]

Check the battery terminals are tight.

 

[Rei]

Funny you would have two with the same problem. Mine has been great, and I've got a dashcam that goes into parking mode for 6 hours after I turn it off.

 

[decrep]

hmm, evidence is starting to point to the user.
Do you have something plugged in?
The OBD dongle draws power even when car is off.

 

[bilbo]

Has anyone else had a problem with the 12v battery becoming drained overnight? I returned my first mgs5 due to this problem and today I have had exactly the same problem with my replacement mgs5, arghhhhh.

Yes, mine did this again yesterday morning. It's preceded by the "USB Recognition Failed" message on the centre screen on start up, then the radio getting stuck on one station, then eventually a battery drain. I have the car booked in for tomorrow for an investigation, but since everything has rebooted now, it's all OK. I'll have to contact the garage to see if it's still worth taking the car in, or just wait till I get the error again and the doom loop begins again.

 

[Shwd mae]

Thanks for the replies. If it's 'the user' I would like to know how? Car is locked, full charge, not connected to charger. Why on earth should the battery become drained?

 

[decrep]

something is draining it,
you have nothing plugged in to USB ports, OBD dongle and every thing else is turned off?
Needs a sparky with a meter to see where the current is going.

 

[Shwd mae]

Nothing plugged in. There was an annoying problem with the tailgate not opening high enough, but no dashcam/cables etc plugged in.

 

[Shwd mae]

Problem has been identified as a drain from the T box.

I also mentioned that my MG app would often log me out and say 'account change, your account is logged in on another device' and this may be connected to the problem.

 

[emmrecs]

I also mentioned that my MG app would often log me out and say 'account change, your account is logged in on another device' and this may be connected to the problem.

Ditto here with that very annoying message but, at least at the moment, I'm not seeing any parasitic 12v drain so the issues may not be related.

 

[cargocare]

Has anyone else had a problem with the 12V battery becoming drained overnight? I returned my first MGS5 due to this problem and today I have had exactly the same problem with my replacement MGS5, arghhhhh.

MG Garage have checked my MG5 for this problem (twice) the problem has reoccurred several times, today they advise there is a switch (part of the foot brake mechanism for turning the car on) which has an intermittent fault, the switch may on occasion not switch off when you leave/ lock the car. They have tested the switch and found it may be the culprit (nothing is 100%) MG Garage are ordering a new switch and discussing which warrantee to charge - my warrantee or MG's, hope this helps