Hi,
Have you found a solution to this? I am in a similar situation and do not have access to an outlet near my parking spot.
My car is notorious for draining battery bc the cooling system stays on for a little after turning off to cool the turbos. I also want to run my dashcam on continuous parking mode which will cobtantly draw a small amount of current. I have a solar panel that I will be installing in the fall, but I want to charge it fully first so the panel only has to maintain. I can remove & bring the battery home if need be but would like to avoid it.
I have a portable compressor/jumper with a 110v outlet. I have to check how many amps it can deliver and see what the trickle charger requirements are. That may be a solution if it all checks out.