Dead car

[Alex1985]

Just got back from a week away to a completely dead car.
Waiting for the AA man.

 

[Vingnut]

12v battery flat I presume?

 

[Alex1985]

Yes, tried to charge it but I think it has a dead short in the battery as it overloads the charger.

 

[Rolfe]

That's scary. I hope it turns out to be a fault, because if we can't leave our cars parked up for a week without them dying on us, we're all in trouble.

 

[PeteC]

That's scary. I hope it turns out to be a fault, because if we can't leave our cars parked up for a week without them dying on us, we're all in trouble.

I would think there must be some sort of problem here. I've mentioned before that we left our car parked for six and a half weeks and it was fine when we got back. I was half expecting a problem as the manual mentions disconnecting the 12v battery if you are leaving it for a longish time (4+ weeks from memory) and I had left ours with the battery connected. As it was, the car unlocked from the key fob and came to life as normal.

 

[Rolfe]

That's reassuring!

 

[MG4NI]

I'm just back from 4 week holiday. Left car on driveway. Car started immediately.

 

[Surfdog]

Just got back from a week away to a completely dead car.
Waiting for the AA man.

Hos much charge was left in your HV battery? Its discussed on another thread that it will not charge 12v battery if HV battery is below certain level of charge.

 

[Rolfe]

As an aside, I went into the Co-op this afternoon and forgot to press the door-lock button (I'm always forgetting that). As a result the DRLs stayed on while I was in the shop. As I came out I was approached by a concerned passer-by saying did I know I'd left my lights on, and he wouldn't want to see my battery go flat.

I'm afraid I didn't resist the temptation to tell him, in a friendly manner, how much battery I actually had backing up these lights.

 

[Deleted member 9909]

On the assumption that intelligent 12v charging works of course given all ancillaries including lights run off the good old 12v battery...

 

[Rolfe]

Well, yes, I was rather making that assumption. Considering that the car was awake at the time, I'd be pretty surprised if it didn't.

 

[Deleted member 9909]

Sorry didn't realise the car was awake...I assumed the car was off but the lights were left on when you went to the shops in which case the hv batteries would not be topping up the 12v battery. There seems to be a few cases where apparent 12v intelligent charging may not have kicked in and the battery has went flat.

 

[Rolfe]

No, it was still awake. I pressed P then just got up and left the car without pressing the door button. It was so awake that when I got back in it didn't even re-start the radio which I had switched off - it remembered that much!

I was only in the shop for about ten minutes. The lights as such weren't on. But these DRLs are very conspicuous and of course they hadn't gone off.

 

[Vingnut]

Sorry didn't realise the car was awake...I assumed the car was off but the lights were left on when you went to the shops in which case the hv batteries would not be topping up the 12v battery. There seems to be a few cases where apparent 12v intelligent charging may not have kicked in and the battery has went flat.

If I have understod it right that's when one have turned off auto lights and forget to turn of the lights when leaving the car after shuting it down. Then it eventually will empty the 12v.

 

[Rolfe]

That's probably true, but I had not turned off the auto lights. All that was showing were the DRLs. Also, I didn't shut the car down. I just got out of it. It was still wide awake - so wide awake that it remembered that the radio was still turned off.

 

[Alex1985]

Hos much charge was left in your HV battery? Its discussed on another thread that it will not charge 12v battery if HV battery is below certain level of charge.

The car was left to charge itself on the solar controller and had reached it’s cut off of 90% after 4 days, so at which point the 12v system was working ok so I did not need to check it after that.

In future I shall keep an eye on the 12v battery voltage on the app whilst I am away.

 

[CarlMG4]

The car was left to charge itself on the solar controller and had reached it’s cut off of 90% after 4 days, so at which point the 12v system was working ok so I did not need to check it after that.

In future I shall keep an eye on the 12v battery voltage on the app whilst I am away.

Bear in mind each time you connect to the app to view the car it wakes the car up and consumes the 12v battery.

 

[Alex1985]

Bear in mind each time you connect to the app to view the car it wakes the car up and consumes the 12v battery.

Yes I appreciate that, but twice in 7 days should not I think flatten the battery. I believe the battery has a dead short in it which has rendered it unserviceable.

I could not recharge it as it drew too much current and was causing the charger to trip, the AA man had the same problem and in my experience that is generally caused by a shorted cell or cells.

He had a spare battery which he installed, then followed me to the garage. The warning lights were on and messages flashing the whole time which I guess just need resetting once the fault is rectified.

 

[CarlMG4]

Yes I appreciate that, but twice in 7 days should not I think flatten the battery. I believe the battery has a dead short in it which has rendered it unserviceable.

I could not recharge it as it drew too much current and was causing the charger to trip, the AA man had the same problem and in my experience that is generally caused by a shorted cell or cells.

He had a spare battery which he installed, then followed me to the garage. The warning lights were on and messages flashing the whole time which I guess just need resetting once the fault is rectified.

No I totally agree, it shouldn't drain it - I was just reminding yourself and others for future reference - every time you lock/unlock/connect via app/Ready - it consumes 12v battery.

So a 12 battery that hasn't had a chance to charge back up, and is running at a low SOC, will only get lower each time you do any of the above, making it likely to cause problems.

Your issue being a duff 12v battery is easily solved thankfully, glad you got it sorted ?

 

[Alex1985]

Issue resolved now, apparently it was a software fault that they have "patched" with a software update and have recovered the battery which I shall be keeping a very close watch on!