Low battery

[Jto]

Hello
I finished work on Christmas Eve and my ZS has not been doing its normal journey to work and back.
Yesterday day I could not do a scan on my phone of the car, it kept timing out; this morning I went out to it and checked the 12 volt battery read out on the screen and it was down to 11.6 volt and the car was iced up so fingers crossed and put it in to ready. Which it did to defrost the car so that the 12V battery had some charge into it.
I know the car has been toping the 12 V battery in the past but do not understand why it has not now. The high voltage battery has 75% charge.

I have sent the above to customer service; can anyoone answer way the 12V battery was not topped up, which car has been doing from the day I got it.
I just checked the 12V battery which has been about 40 minutes and the battery is still at 13.1V which is what it was when I switched the car off and the outside temperature is still 0°C. I think at the weekend I will put the 12V battery on to a charger.

 

[hmadsen]

As long as the 12V battery has enough charge to start up and energize the HV battery contactors, the battery should be charged and the car should not run out of LV power.

Cold weather dimishes the battery's capacity, so it could be that your battery is just on its way out and unable to hold as much charge as it used to.

I seem to have read about other people that had to change the 12V battery quite quickly, something with the factory fitted battery, being of "questionable quality"

Maybe the car just needs a new battery.

 

[Jto]

Yes we all know the 12V batteries are not the best but the car from new to now I've seen it charge the 12 volt battery but not this time. Will be keeping an eye on this.

 

[hmadsen]

Yes we’ll know the battery’s are not the best but the car from new to now I seen it charge the 12 volt battery but not this time, will be keep a eye on this.

Thats the thing with batteries, they go weaker and weaker and you most often find that when it gets low and you then combine that with cold weather, this is when it will become a problem.

Ask anyone selling or replacing batteries, they will tell you that they sell the most batteries in winter

If you can get it to last a few months the weather will be warmer and it will probably be able to do one summer season more, but then you need to proactively replace it before next winter

 

[Coulomb]

I seem to have read about other people that had to change the 12V battery quite quickly, something with the factory fitted battery, being of "questionable quality"

I think it's more that the treatment of the batteries while in storage that is questionable, especially extended storage around covid.

 

[Coulomb]

I just checked the 12V battery which has been about 40 minutes and the battery is still at 13.1V which is what it was when I switched the car off and the outside temperature is still 0°C. I

If that 40 minutes was with the car not in ready mode (so not charging the 12V battery), then that sounds to me that the 12V battery is still pretty good. 1-2 hours resting would be more convincing though.

I wonder if the ECU that normally does the charge of the 12V battery glitched somehow. If you find the 12V not being charged now, try disconnecting the 12V for a minute or two and check again.

I can't think of a reason that the car would not charge the 12V just because the outside temperature is below 0°C, or if the main battery gets cold. That would be bad for all the owners in very cold areas.

 

[Jto]

Just a up date
Last few days it’s been very cold down to -2 degrees at night but the 12v battery has been fine at 13.2 volts and have seen the battery charged back up when it’s gone below the 13.2. The only thing I can think of is for the two days it was sat I did not interacted with the car and it had gone to sleep until I got in on the 3rd and started it up. Even MG could say why.