12V Battery dead, how to charge?

A

ATILKURT

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MG ZS EV
Hi All,
My 12V battery is dead and I can't start anything on the car. I got in with the key.
Is there a way to open the charging cap so I can connect the car to my charger? The car's main battery has %70 charge and I used the car 2 days a go.
 

Manual release is at approx 3.59, I am not sure if this unlocks the flap as well (could you please let us know?)
Many of us carry one of these around


You can also get at halfords, otherwise a call to the AA and they will fix for you? (do you know why battery is flat, if not you may need to get car checked for leakage).
 
If you can pop the hood they put a 12V charger on the 12V battery, it doesn't have to be on there long just enough to get you into ready mode for the HV battery to start charging the 12V battery
 
It’s a manual cable pull system to release the bonnet.
It’s on the drivers side, right hand lower section of the dash panel.
Charge the 12 volt battery or use a booster pack to bring the battery back to life.
I would consider giving the 12 battery an over night charge from a smart charger unit.
 
Thanks all. Sorted it out.
I believe this happened because of the new version of the MG App. I downloaded it 2-3 weeks ago and since then 12V battery started acting weird. I believe the app has been working in the background, refreshing and asking the car to communicate and update continuously which drains the 12V battery.
 
I’ve come back from a 2-week holiday yesterday, to find my 12v also dead. Couldn’t unlock the car, and nothing powered when I got inside using the manual key open.

I don’t understand what’s caused it. I barely checked the app over the two weeks, and the dashcam I have is hardwired to a fuse that only gives power when the car is ready…

Luckily I have a booster for the battery, otherwise I’d be calling recovery! Why does this problem exist, MG?!
 
benfello said:
I’ve come back from a 2-week holiday yesterday, to find my 12v also dead. Couldn’t unlock the car, and nothing powered when I got inside using the manual key open.

I don’t understand what’s caused it. I barely checked the app over the two weeks, and the dashcam I have is hardwired to a fuse that only gives power when the car is ready…

Luckily I have a booster for the battery, otherwise I’d be calling recovery! Why does this problem exist, MG?!
Click to expand...
I'm leaving mine for nearly 3 weeks whilst on holiday but I won't use the app and wake stuff up. Lucky you had the tools and knowledge to get it going.
 
My ZS EV is just over 12 months old and very time I turn the car off I get a message saying the 12 volt battery is low. It is showing 11.3 volts and when the car is running it shows 14.6 volts.
If I charge the 12 volt battery is it necessary to disconnect it from the car or can I just put the charger leads on the battery and charge it up?
 
I have a CTEK smart charger that has a short set of fly leads that are permanently attached to the battery.
So I just have to attach the smart charger to the short loom on the battery, plug it into a 13 amp socket and off you go.
So, the battery stays in place on the car.
Always use one of the modern smart chargers and not the older type chargers.
 
Have you got a booster pack in the car? Because at 11.3 volts, one day the car is going to refuse to start. I think a new 12V battery is in order.
 
I have this kind of problem with my 12V - even charging from the HV charger - which should charge the 12V too - doesn’t get rid of the low battery warnings.
I have a NoCo Gen 2, which is only a charger-maintainer with no internal jump start battery but you can leave it attached to the car for the weeks or so that you’re not using the car. Once the NoCo has charged the battery, it goes into maintenance mode - trickle charge - and keeps the battery topped up, so if you have any 12V draining - however small - you’ll always have enough battery charge to start.
My biggest problem is that I don’t have an outside mains connector to plug the charger into so I plug in to an inside socket and run an official extension lead from the unit to the battery out of my letterbox!
Gives the postman a pause, I can tell you - it also keeps away a meddlesome kid that lives next door that used to ring my doorbell - 😀
 
Last edited by a moderator:
Coulomb said:
I wonder if it reduces junk mail. The postie more or less has to deliver the mail, but junk mailers might just skip that dodgy looking letter box. ⚡😈
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It’s totally safe though as only DC going through the wires. What makes it look really dodgy is the red and black colour of the wires…
I’ll drill a hole in the outer wall soon though but it’s a pig, as I have 1930’s pebbledash- real pebbles sunk in concrete!
I have an SDS drill that should make short shrift of it - only needs to be about 2cm diameter and sloped downwards of course to prevent any water ingress. Might line it with a plastic pipe with end caps though, just to cover it when not in use.
 
Spinynorman said:
It’s totally safe though as only DC going through the wires. What makes it look really dodgy is the red and black colour of the wires…
I’ll drill a hole in the outer wall soon though but it’s a pig, as I have 1930’s pebbledash- real pebbles sunk in concrete!
I have an SDS drill that should make short shrift of it - only needs to be about 2cm diameter and sloped downwards of course to prevent any water ingress. Might line it with a plastic pipe with end caps though, just to cover it when not in use.
Click to expand...
The granny charger has 230V AC mains on it not DC. The charger is in the car.
 
Jomarkh said:
The granny charger has 230V AC mains on it not DC. The charger is in the car.
Click to expand...
True enough but we’re discussing the 12V battery - not the drive battery!
Plus the granny charger is one piece - couldn’t get that through my letterbox if I tried…
Add to that, I have my own drive train charger (a Zappy 2) so haven’t used the granny for years…
 
benfello said:
I’ve come back from a 2-week holiday yesterday, to find my 12v also dead. Couldn’t unlock the car, and nothing powered when I got inside using the manual key open.

I don’t understand what’s caused it. I barely checked the app over the two weeks, and the dashcam I have is hardwired to a fuse that only gives power when the car is ready…

Luckily I have a booster for the battery, otherwise I’d be calling recovery! Why does this problem exist, MG?!
Click to expand...
Is this a confirmed issue affecting all (MG ZS EV) cars?
 
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