Recommendations on a trickle charger??

I have that 3 day show coming up in harrisburg, and the truck has to be parked from the time you get there (indoors) till the time the show is over. If my neons and strobes are going to be on for the length of the show each day, im going to need a trickle charger i can plug into an outlet so the battery will charge each night. Does anyone have any info on these...prices...?

Thanks,
Tom