12v battery charging when plugged-in?

RichS · Tuesday at 11:25 AM

Hi. I have a new HS PHEV. It has been OK for a few weeks, but I now have issues that appear to be linked to a lowish 12v battery charge.

I previously had a Ford Kuga PHEV. When it was plugged-in the app would occasionally display "charging 12v battery" other than when the traction battery was scheduled to charge. It appears the MG does not charge its 12v battery when plugged-in (unless switched-on/ ready). Is that correct?

Last night, for the first time, the car did not charge as scheduled overnight. I could not find any problem with connectivity. Might this be related to low 12v charge?

The MG app also would not update the car status, but timed-out. Could this also be related?

Edited... Just found this in the manual -
"Intelligent Charging
When the vehicle is powered OFF and the system
detects that the 12V battery is running low, the vehicle
will automatically charge the 12V battery under certain
conditions to ensure the vehicle starts. This function will
be automatically turned off upon completion of charging."

Although the HV battery wasn't full, it had ample charge so, presumably, if low, the 12v should have been charged.

Thanks for any help.

Rich

Jto · Tuesday at 4:03 PM

If your car is few years old you are having 12v problems now you need to replace it as it’s not holding charge. If you have a meter check the standing voltage then turn car on to ready and check voltage again and if car is changing the battery should be over 14 volts you know charge is going it the 12v battery but is not able to hold.

RichS · Tuesday at 6:06 PM

Jto said:
If your car is few years old you are having 12v problems now you need to replace it as it’s not holding charge. If you have a meter check the standing voltage then turn car on to ready and check voltage again and if car is changing the battery should be over 14 volts you know charge is going it the 12v battery but is not able to hold.

It's a new car.

Just returned from a long trip, and the app is now connecting and reports the battery at 12.7v turned-off. I also noticed it at 14v when turned-on. I checked battery connections, earlier, and the negative didn't seem as tight as it could be so have tightened it...

Jto · Tuesday at 6:25 PM

The battery should be round 13 to 13.1 after switch off, tightening the negative was good but the battery is a bit low at switch off. If it new take it back and try to photo evidence of the problem. See if you can see a date on the battery you may find it’s up to a year old. Only a capacity test will give the condition of the battery. Just to let you know when I have my car on charge I check the 12v battery on the app and see it charging at 14.2v

RichS · Wednesday at 8:10 AM

Thanks, again. The car didn't charge again, last night, but I now suspect that may be because the charger was not locked-in completely. I have been reading on this forum how dodgy the connection is, and I have certainly heard the connector trying to latch after I've plugged it in! Eventually I managed to start the car charging, and the 12v was showing 14.1v in the app while charging. I couldn't find a date on the battery...

Jto · Wednesday at 8:24 AM

You can tell the plug is not locked by listening to the locking motor will try a few times I used to push the plug and keep hold of it the keep it square on until the motor had run and could feel it locking through the plug.

12v battery charging when plugged-in?

RichS

Novice Member

Jto

Prominent Member

RichS

Novice Member

Jto

Prominent Member

RichS

Novice Member

Jto

Prominent Member

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