Dead car / flat 12 volt battery 😰

[Archev]

Nipped out for a wee jaunt in the 5lr and immediately our nip was nipped in the bud.
The car was dead, the key was doing nothing the doors were locked, the charge flap was locked - no entry.
Used the manual key to pop the lock cover behind the door handle and unlocked the door. Nothing electrical was responding inside the car.
Opened the bonnet and employed the famous 10 mm spanner to disconnect the battery post for half a minute. Reattached everything but still nothing.
Called the AA number and had a patrol van pull up 35 mins later. The battery had 4 volts in it so the patrolman connected his charger for ten minutes then discovered that some twit had left the lights on. Now sadly the finger of blame in these instances points at the most recent driver. There has only ever been one such miscreant so prepare that doghouse- I’m coming in
I’ve now set off for a little run to charge the 12 volt and top up the traction battery.
I’ve offered to take my darling wife out for dinner at the same time.
Is this romantic gallantry or am I just a coward ??
Keep that light switch at automatic folks

 

[Alb]

I'm sure it gives you a warning if you lock the car and leave the lights

 

[Lovemyev]

I’ve now set off for a little run to charge the 12 volt and top up the traction battery.

The 12 volt battery will receive charge from the traction battery, when the car is in the READY mode, but not in the standby mode ( push the start button without your foot on the brake ).
Taking the car for a "Run" offers the same as the car standing still in the READY mode.
Idea:- Maybe you may want to consider investing in a small booster pack, that you can leave in the car just in case you leave the lights on again by mistake ?.
Saves waiting for the recovery services !.

 

[Archev]

The 12 volt battery will receive charge from the traction battery, when the car is in the READY mode, but not in the standby mode ( push the start button without your foot on the brake ).
Taking the car for a "Run" offers the same as the car standing still in the READY mode.
Idea:- Maybe you may want to consider investing in a small booster pack, that you can leave in the car just in case you leave the lights on again by mistake ?.
Saves waiting for the recovery services !.

Already considered but thanks

 

[Archev]

I'm sure it gives you a warning if you lock the car and leave the lights

Aargh - am I going deaf and blind on top of all this do you reckon ?

 

[biffo]

Aargh - am I going deaf and blind on top of all this do you reckon ?

I sometimes manually operate the lights when driving in rain at speed - my last car had a useful feature where the lights would come on automatically if wipers were operating when at motorway speeds - sounds like a simple software feature / menu option that MG could add given all the sensors exist. Along with an option for a special @Archev volume level for the lights on warning

 

[PhevsamHS]

Aargh - am I going deaf and blind on top of all this do you reckon ?

Why is there no timeout on the lights/electrics? As some ICE do have this run for 15mins then goes into ECO mode to save battery. Also it would not take too much to monitor 12V and when it gets to a low voltage it shuts down.

 

[biffo]

Why is there no timeout on the lights/electrics? As some ICE do have this run for 15mins then goes into ECO mode to save battery. Also it would not take too much to monitor 12V and when it gets to a low voltage it shuts down.

You can really see which companies just make cars rather than software when it comes to all these features - admittedly, some are childish and naff, but some are really useful.

 

[Archev]

I sometimes manually operate the lights when driving in rain at speed - my last car had a useful feature where the lights would come on automatically if wipers were operating when at motorway speeds - sounds like a simple software feature / menu option that MG could add given all the sensors exist. Along with an option for a special @Archev volume level for the lights on warning

I refuse to drive around with a shipping foghorn on the roof I’m sorry

 

[Mg5van]

The best thing on the Tesla is the fart button.
How have we managed without that in our pesant spec motors.

 

[Ozzie1989]

The battery had 4 volts in it

A 12v lead acid battery is fully discharged at 10.8v - anything much below this will start to affect the chemistry and bend plates etc.

At 4v the battery will have most definitely sulphated and it's capacity will now be greatly reduced.

Keep an eye on it (especially in cold weather) and if it shows signs of high voltage drop overnight get it replaced before it lets you down!

Surprised the AA guy didn't tell you this but then again the last AA guy who attended one of our fleet vans couldn't find the problem with his computer yet when we got it back the plug had come off an injector right on top of the engine in plain view!

 

[Archev]

A 12v lead acid battery is fully discharged at 10.8v - anything much below this will start to affect the chemistry and bend plates etc.

At 4v the battery will have most definitely sulphated and it's capacity will now be greatly reduced.

Keep an eye on it (especially in cold weather) and if it shows signs of high voltage drop overnight get it replaced before it lets you down!

Surprised the AA guy didn't tell you this but then again the last AA guy who attended one of our fleet vans couldn't find the problem with his computer yet when we got it back the plug had come off an injector right on top of the engine in plain view!

Oh wow - cheers Ozzie 1989. I’ll pay very close attention to that. Many thanks for that heads up

 

[deviousrich]

out of interest do you know how long did you leave the lights on for?

i happen to have done the same over xmas when visiting someone i left the lights on all day but i was presently surprised that the car hadn't drained the battery completely (left on for a good 8 hours) - maybe i got away with it?

it was absolutely pissing it down with rain when we got to our visit and im sure the car did "bing" at me when we got out, but im sure i didnt hear it with the kids and the rain - its easily missed folks!

 

[PhevsamHS]

Oh wow - cheers Ozzie 1989. I’ll pay very close attention to that. Many thanks for that heads up

 

[PhevsamHS]

Well I would want the battery fully tested as 4V is way too low. As I am sure the age of the battery is not that old! I would be wondering if this battery was not weak in the first place.

 

[biffo]

I suppose technically, a pair of 20W LED bulbs could be left on for twice as long as 60W Halogen HB3 bulbs before draining the 12V battery

Your battery should be less than 12 months old - even if sitting around before fitted to car when built around June time?

I bought last battery (not for my MG) from Tayna - managed to get a massively higher spec Yuasa battery compared to OEM for similar money. Typically, no one lists MG compatible batteries on their searches. The AA also changed one on another car as air intake had to be dismantled.

 

[AnonymouseDriva]

out of interest do you know how long did you leave the lights on for?

i happen to have done the same over xmas when visiting someone i left the lights on all day but i was presently surprised that the car hadn't drained the battery completely (left on for a good 8 hours) - maybe i got away with it?

it was absolutely pissing it down with rain when we got to our visit and im sure the car did "bing" at me when we got out, but im sure i didnt hear it with the kids and the rain - its easily missed folks!

Which model of the 5 do you have? Some models will monitor the 12V battery state even when 'off' and top it up from the main battery. I'm assuming the LR Exclusive does, but don't know at what spec level that applies to as it's not clear in the manual. It has a * to say not all models, but nothing more specific than that.

 

[Archev]

Aye the car was collected in September. It was sitting for almost two days since last use so that’s concerning.
We went over to the Stirling hub last night for a free charge and had 70%in the traction battery and 14.2 in the 12 volt when we parked up back at home. I’ll check it after I’ve enjoyed my porridge (pinhead oats, water no salt and cooked in the old tradition of the clans - in the microwave )
As an aside, last night there were three CCS chargers in use when we arrived We set about using the fourth but the girl on number 3 said it wasn’t working. I phoned CPS and the guy said #4 had been reported earlier in the day and was scheduled for attention.
We waited 15 minutes and plugged in as a car left. As we sat a car drew in and parked at the dead unit. Low and behold it was the SWARCO engineer . I was going to go and have a word with him but he was finished and gone when I looked round again.

 

[Archev]

Which model of the 5 do you have? Some models will monitor the 12V battery state even when 'off' and top it up from the main battery. I'm assuming the LR Exclusive does, but don't know at what spec level that applies to as it's not clear in the manual. It has a * to say not all models, but nothing more specific than that.

Ours is a long range exclusive.

 

[biffo]

Aye the car was collected in September. It was sitting for almost two days since last use so that’s concerning.
We went over to the Stirling hub last night for a free charge and had 70%in the traction battery and 14.2 in the 12 volt when we parked up back at home. I’ll check it after I’ve enjoyed my porridge (pinhead oats, water no salt and cooked in the old tradition of the clans - in the microwave )
As an aside, last night there were three CCS chargers in use when we arrived We set about using the fourth but the girl on number 3 said it wasn’t working. I phoned CPS and the guy said #4 had been reported earlier in the day and was scheduled for attention.
We waited 15 minutes and plugged in as a car left. As we sat a car drew in and parked at the dead unit. Low and behold it was the SWARCO engineer . I was going to go and have a word with him but he was finished and gone when I looked round again.

I bought a porringer (or double boiler for those without a clan affiliation!) a few years back - when I've time to use it, makes fabulously creamy porridge.