"12v battery charging low. Don't stayed parked more than 3 days"

There are a few threads about poor 12v batteries and reoccurring issues with warning lights on the dash etc. If the voltage goes to low you might not get the car into ready mode.
 
GameZone said:
Getting this message on my screen. Also the app has stopped communicating with my car.

Ideas?
Click to expand...
I had this after leaving my car for several days but many interrogations via the app and also unlocking / locking the car. Drained a weakened battery
I had to unlock the car to open the bonnet with the key in the remote. you have to use that key to pry off the cover on the door handle to expose the manual lock.
Result was that I had to disconnect the battery and charge it back up again. Not had the issue since

Is your car new?, the battery may have been low when you collected. Also, check that the terminals are tight on the battery as they are disconnected for shipping and sometimes not tightened back up properly.
 
PristDean said:
I had this after leaving my car for several days but many interrogations via the app and also unlocking / locking the car. Drained a weakened battery
I had to unlock the car to open the bonnet with the key in the remote. you have to use that key to pry off the cover on the door handle to expose the manual lock.
Result was that I had to disconnect the battery and charge it back up again. Not had the issue since

Is your car new?, the battery may have been low when you collected. Also, check that the terminals are tight on the battery as they are disconnected for shipping and sometimes not tightened back up properly.
Click to expand...
The voltage is 14v when charging my car so the battery must be charging I guess?
 
I had my brand new MG4 for 14 days (247 miles on the odometer), when 40 minutes into a drive the 12v battery light came on. Not long after on that same drive the car just STOPPED mid junction: hazards wouldn’t work, couldn’t put it even in neutral to move it. Very scary situation. AA had to recover it and MG has now had my car 13 days, still cannot tell me what went wrong (the main battery charged to 64% when it happened). Even if I don’t think a brand new 12v should have no charge so quickly, I could accept it if the car just didn’t start. But I can’t accept the battery becoming decharged mid drive and then just shutting off on me as I was driving!

Anyone had similar?
 
racheltoutcourt said:
I had my brand new MG4 for 14 days (247 miles on the odometer), when 40 minutes into a drive the 12v battery light came on. Not long after on that same drive the car just STOPPED mid junction: hazards wouldn’t work, couldn’t put it even in neutral to move it. Very scary situation. AA had to recover it and MG has now had my car 13 days, still cannot tell me what went wrong (the main battery charged to 64% when it happened). Even if I don’t think a brand new 12v should have no charge so quickly, I could accept it if the car just didn’t start. But I can’t accept the battery becoming decharged mid drive and then just shutting off on me as I was driving!

Anyone had similar?
Click to expand...
Had flat battery issues from new in May (MG4 SE long range) It took 2 months to get it booked in to be looked at in the meantime I was advised if it happened again call the AA which I did. 5 times the battery went flat. Last week when it went in to the dealer Mark the Technician told me it is a known issue. The R16 s/w update should fix it. He was happy the battery dropping to 12.1 volts was normal (??). The AA man said all he seems to get at the moment is call outs to MG4 and Toyota flat batteries. Waiting nervously to seem if its fixed.
 
seibegee said:
Had flat battery issues from new in May (MG4 SE long range) It took 2 months to get it booked in to be looked at in the meantime I was advised if it happened again call the AA which I did. 5 times the battery went flat. Last week when it went in to the dealer Mark the Technician told me it is a known issue. The R16 s/w update should fix it. He was happy the battery dropping to 12.1 volts was normal (??). The AA man said all he seems to get at the moment is call outs to MG4 and Toyota flat batteries. Waiting nervously to seem if its fixed.
Click to expand...
I very much doubt a software update will fix this issue. What your dealership will need to do is likely update your BMS (Battery Management System) modules firmware.
The 12v should be charged from the main battery periodically to keep it topped up when not plugged in. If this does not happen (you can see on the app, by chance, if the car is not charging and the battery shows about 14.xV) then you need it fixed with a BMS update.

Plus... please read this thread to avoid duplication

!2v Battery Charging
 
PristDean said:
I had this after leaving my car for several days but many interrogations via the app and also unlocking / locking the car. Drained a weakened battery
I had to unlock the car to open the bonnet with the key in the remote. you have to use that key to pry off the cover on the door handle to expose the manual lock.
Result was that I had to disconnect the battery and charge it back up again. Not had the issue since

Is your car new?, the battery may have been low when you collected. Also, check that the terminals are tight on the battery as they are disconnected for shipping and sometimes not tightened back up properly.
Click to expand...
Looks like I have to charge it then. The car is almost a year, but we drive short trips, and use the app a lot (may reduce now). So it didn't happen again after charging the battery? How long since you charged the 12v?
 
So I fully charged the 12v battery, drove a bit, and got the same "12v low battery" message in the car. All though everything except iSmart is currently working.
 
GameZone said:
Which update is this? They already updated the firmware that goes for my home charger.
Click to expand...
Battery Management System... this is responsible for enabling your high volt battery to top up your 12v when it gets low. This should occur when you are driving, stationary and locked or charging the car. I do not have any version numbers
If your dealer says you are at the latest firmware version and your battery shows as charging in the above situations (showing 14.x v) then your battery needs to be replaced
 
PristDean said:
Battery Management System... this is responsible for enabling your high volt battery to top up your 12v when it gets low. This should occur when you are driving, stationary and locked or charging the car. I do not have any version numbers
If your dealer says you are at the latest firmware version and your battery shows as charging in the above situations (showing 14.x v) then your battery needs to be replaced
Click to expand...
Yeah but as I mentioned I fully charged the 12v before driving only 3km, just to have the low battery message again. Seems like a bad battery to me. I could be wrong, but back to the dealer I guess.
 

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