How long can a car 'sit' before you would need AA or battery topper to start it?

[KXL]

Dear All,

So I would need to leave my car outside (in a secure residential carpark) for a good 2 maybe 3 months, going away for that duration. Plus it's getting cold. On a fully (ish) charged car battery, anybody has any experience on whether when I return after 3 months the battery is likely to be dead, or it should still have enough to unlock, and start, afterwhich I really need to take a long ish journey to charge it back up?
Thanks!

 

[BoomerBoom]

With a brand new battery, fully charged and no electrical problems then yes, it should still be able to start the car.

If the battery isn't new then all bets are off and you'd be advised to make sure your breakdown cover is adequate to get you going.

 

[andycupra]

I think you could be in trouble. but ultimately depends on what systems the car has that run when its parked up. eg alarms, dashcams with parking modes etc. or simply a minor drain.

 

[Speedbird]

I have been away for 4 months, and my car has started fine when I got back. This was an Audi A3 2.0 TDI. Had no ill effects on the car, but I did put fresh fuel in on the first journey.

 

[BigJase88]

I would say anything more than 3/4 weeks it’s likely to be dead as a dodo

 

[SRGTD]

@KXL; is there no one you could entrust with giving your car a run every couple of weeks while you’re away? It’s during the colder, winter months when issues due to lack of use are likely to manifest themselves, such as battery issues.

I’ve got a friend who faced the same dilemma a few years ago when they went to work overseas for 6 months. They left their car at mine, put me on their insurance as a named driver and I took the car for 10-15 mile run every couple of weeks. It kept it ticking over and in good health, and I quite enjoyed by fortnightly runs out in a car with 3.2 litre engine!

 

[queen]

If I had to guess I'd say at least 1 month, though you could always just disconnect one pole to avoid discharge.

 

[Kirky]

I was away for 4 months at the start of the year. No issues when I got back and started the car. Not even a battery low warning. I've got a dashcam hardwired too, so I was extremely surprised.

 

[BoomerBoom]

They sometimes sit for many months during the manufacture, shipping and storage process - albeit with new batteries. It's only as they age and cold reduces the charging and starting capacity, until nothing is left.

 

[KXL]

Thanks all, anybody had experience with those powerbank battery chargers? Car is a 68 plate....during lockdown it sat 1 month, but the weekend before, I did a 130 mile return journey. Started no issues, I'm confident, 2 months it's ok...however...past that...I'm 50:50...plus during lockdown it was getting warm, now it's getting cold, luckily, London, cold is not like Scandinavia! Car has no dashcam etc, just the blinking red alarm light, that's it!
Thanks for the idea on getting someone to 'baby sit' my car...I might do just that, I recall they had house with 3 car parking drive...and they only had 1 large SUV, they might enjoy the smaller car for local trips!

 

[BigJase88]

After about 4 days my van is pancaked

 

[KXL]

OK, so I last left my car outside (and this year's winter is COLD) since the end of October 2020, battery was fully charged ish, took a long drive prior, and just returned, pressed teh remote, yes it unlocks, turned the ignition, and it starts! Didn't even struggle to. Look like 68 plate batteries are still good!