I have a camper with 12 volt deep cycle battery to operate lights. But I am bit confused as to which solar battery chargers do I need for this battery. What type do I need to keep my battery charged while using? Do I need to keep in mind about the size or ampere or voltage of solar panel? What do I look for in solar powered battery charger for a 12 volt RV battery? I would really appreciate your useful information pertaining to my query. Thanks.