How do I use the mechanical key?

kimptoc

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MG4 Trophy LR
Trying to open the car today and neither of the key fobs work. Seems like an issue with the car.
Car had around 50% charge 2 days ago
Totally failing to finding where I put the mechanical key to see if that might bring it to life.
Not seeing it in the manual other than how to get it from the fob.
Thanks in advance.

Ok. Got in thanks to this video - but no life in car
 
Don't currently have one but RAC on they way so they hopefully can do

Confirmed it's a bad battery. At least now it's charging and boosting the 12v battery somewhat. Just not confident it's worth driving in, if I stop anywhere is it likely to die again 😢
Now Trying to get through to the dealer to arrange a replacement.
 
Confirmed it's a bad battery. At least now it's charging and boosting the 12v battery somewhat. Just not confident it's worth driving in, if I stop anywhere is it likely to die again 😢
Now Trying to get through to the dealer to arrange a replacement.
The 12v battery is charged from the main vehicle battery when it's in it's ready state i.e. the car has someone in the driver's seat and is switched on (put into D). If the car is in what used to be called aux the 12v battery will eventually loose its charge.
So sitting in the car listening to the radio or playing with the settings will flatten the 12v battery similar to listening to the radio in an ICE car with the engine not running.
 
The 12v battery is charged from the main vehicle battery when it's in it's ready state i.e. the car has someone in the driver's seat and is switched on (put into D). If the car is in what used to be called aux the 12v battery will eventually loose its charge.
So sitting in the car listening to the radio or playing with the settings will flatten the 12v battery similar to listening to the radio in an ICE car with the engine not running.
Thanks, Ian - so what charge it has now is probably from what the breakdown guy did. Still waiting to hear from the garage on what they can do.
 
Thanks, Ian - so what charge it has now is probably from what the breakdown guy did. Still waiting to hear from the garage on what they can do.
If you can get into READY mode can you see what voltage the 12v battery has?
 
You'll find the battery voltage in the Tyre Pressure display (on the right side of the driver screen). In READY state you should see 13.8V+ which means it is charging the 12V battery. When the car is shutdown you can find the battery voltage by scanning the car in the iSMART app.
 
The 12v battery is charged from the main vehicle battery when it's in it's ready state i.e. the car has someone in the driver's seat and is switched on (put into D). If the car is in what used to be called aux the 12v battery will eventually loose its charge.
So sitting in the car listening to the radio or playing with the settings will flatten the 12v battery similar to listening to the radio in an ICE car with the engine not running.
Correct - I had this exact issue recently..

Kimptoc - Non of my keys worked to open the car etc etc .. Eventually gained access to the car (yeah that's a fun thing to do) .. I had to Call the AA c/o MG assistance - Chap arrived - Boosted the 12v - Car started as normal..

Probable reason - Very Simple - I had given the car a decent clean the day before - All doors open - Bonnet open, radio on - & yes the Internal lights had been on etc etc ...

Issue - HUMAN error :cool: - I simply did not think that the car would drain the battery enough to not allow it to start the following day .. I should have plugged in the main charge cable after my cleaning - then the car would have charged & topped up the 12v.. Simples when you understand how it works..

Now I carry a Nocco GB40 portable jump start (just in case a Human does something silly) - I'll probably never need it - But my family members might - So no worries in having it
 
12V batteries in EVs tend to be tiny. They don't have to turn over a combustion engine, they just have to power up the electrical system. So they go flat much quicker than in any ICE car.

When I vacuum the car or when my child plays in it I always put it in READY mode. Then the power is extracted from the high voltage battery and the 12V keeps its charge.
 
Last edited:
Thanks, All - the breakdown guy confirmed it was charging when the car was plugged in. But also confirmed the 12v battery is no good.
I used it on Monday/Tuesday - short (6 miles each way) commute, and it had 50% capacity. I did nothing with it yesterday.

Took it to the garage today. They tested the battery and found it's ok. Only thing they could suggest was that it was cold(6c) when break down people tested it and so that might show a worse reading. Not impressed with the garage. Only told me this when I collected the car and not earlier in the day when maybe they could have done further checks
 
Here is a quick update on this. It happened again yesterday. Definitely not cold related (~20c)
Used the battery charger I got after the first time this happened. Powered up straight away. Gave it 10 mins and it seemed fine to drive away, which I did. 30mins drive to work. Left it and worked fine coming home in the evening.
12v battery was showing 13.8v while driving.
A day later the car is off/just been fully charged. The app shows the 12v battery is at 12.9v.
Strange.
 
12v battery warranty is only 12 months, so they obviously don't have a huge amount of faith in them that they are only covered for a year.

If you are still in the first year I'd be trying to get it swapped out.
 

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