Port of Tilbury-Police Constable

[miffy + 74]

So as a result of non-essential travel and working from home, I haven't driven my car for over 3 weeks now, and the battery is completely dead. It was on its way out, when it was cold, it would take a few goes before the car would start. Also if I move off from stationary, the car lights dim and the air-con powers down a bit.

I have a booster pack at home to jump it, however having a look online, it says if I jump a completely dead battery, I risk damaging my car. Is that true and what sort of damage could happen?

Bit of background, its a 9 year old car, with a 7 year old new battery. I've got no use for the car now, so it's not a priority to fix, but should I not bother jumping it and just buy a new car battery for it?

[Beaker 817]

Just buy a new battery if it's dead and 7 years old.  It'll possibly come back, and jumping it from a battery pack won't make a huge difference, but it might not take charge again if it was already on it's way out.  Even worse it might take a bit of charge, and leave you stranded outside the supermarket or at work. 

[Shmook + 532]

Yep, what Beaker said. 

You'll have to suck it up and get a new battery. Also, jumping some cars can damage the smart charge system, so read the manual to check if you decide to go down that route. 

[Ether + 1,398]

Buy a cheap battery charger and leave it on for 24 hrs. May work may not but a cheap battery charger from Lidl will cost you about£7