Dead battery after side lights left on all day

[AmandaP]

Did a 180 mile round trip last night with a super charge in between at the service station close to Stsnstead. Got home this morning with 21 miles left on the battery, think I was so tired I must’ve either not switched the car off or left the side lights on but the lights were on this evening when I went out to plug the car in to charge. It came up with a warning on the dash in red, to “switch car on immediately due to battery something or other” (can’t remember the full message) but the car wouldn’t switch on and then the alarm went off and now it’s totally dead and won’t charge. Any idea about hoods I can get it to charge? Thanks for any advice or guidance on this.

 

[javiermi]

Can you open the car doors?
If you can't this is a symptom the Auxiliary Battery ( 12V) battery is flat
There is a thread in this forum on how to open the door with the emergency key - can't remember where, and would have to search - If that is the case, open the door, then open the bonnet and charge the 12V battery with a normal car battery charger, until is full ( or near)
If the main battery needs charging, just plug the charger and wait until it charges and when you have charged it, when you put th car in "ready" ( button in green), it will start charging the aux battery also - but at the expense of the main battery ( why it needs to be charged first)
As I said the easiest thing if the aux battery is flat is to recharge it

Hope this makes sense

 

[Cocijo]

You can also jump start the car by jumping the 12v battery with another car or a battery pack if you know how to do this - then just set to ready and that 12v will charge up. Or call the AA if you’re stuck - they’ll have the MG‘s reg. on file.

 

[Lovemyev]

Do yourself a favour and buy a battery boaster pack, ready for the next time !.