Battery charging from portable booster, possible?

[dougt]

Hi,

my car doesn't get used as often as I'd like. Sometimes in the winter it will only just start because the battery is getting towards flat from lack of use. The problem I have it that my parking space is in an underground carpark and there's no power.

The car is full of electronics (it's a CLK55 AMG) so I don't want to fit an isolator switch as I think it would cause all sorts of mayhem.

So I was wondering if I got one of those portable booster packs and connected it to the car battery once a week would it charge it up enough to solve the problem?

Thanks for any advice

Doug

[dougt]

Thanks everyone for the helpful suggestions, much appreciated