Trickle Charger - portable?

[Old Skool]

Some advice please. I think I need a trickle charger but the car lives outside away from sources of power. Is there such a think as a rechargeable trickle charger which is “powered up” from the mains and then just left connected in a locked boot to do its thing until drained? If so any recommendations and if not any other ideas?!

Thanks

OS

[kevinf]

Solar charger on the dash plugged into the lighter socket ?

[BiggaJ]

As above or using the the rear lighter charging port found behind the panel on the right side of the boot (trunk), put the solar panel in the rear window on the parcel shelf.

[Shnozz]

What sort of period are you talking about on non-use? My solar charger worked well albeit with an extended period of non-use due to Covid I have swapped to a CTEK.

[8Tech]

I have a jump starter pack that has a 12V cigar lighter socket so assume that you could connect this to the charging port on a car and let it maintain a charge, then bring the pack in every now and then to recharge it?

You would effectively be using it as a power bank.

A good one is pricey though, the cheap ones for sale are complete rubbish.