I agree with mglavin. Go with the 12v field type chargers when on the road. If you want to charge with 110vac chargers, set up a retractable extension cord in the trailer wired to a couple outlets. When at home just pull the cord out and plug into an outlet. If you're pulling from the vehicle to charge your 12v trailer battery, install a fuse that is sized for the wire used. Todays alternators will put out atleast 100 amps that will fry a small gauge wire if the battery is way down. Yes I installed a 130amp alternator where a 70amp was. Cooked the charging circut in the truck after leaving the lights on too long with engine off!