Some people are perplexed to learn that you need more than one battery for your RV. Size matters, and it’s much more effective to build a battery bank for your RV by wiring batteries either in series or in parallel. Wiring batteries in parallel will increase your amp hours but not voltage. Wiring in a series will increase your voltage but not your amp hours. One 12-volt 24 groups deep cycle battery will provide between 70 and 85 AH, while two of them wired in parallel will increase the amp hours (effectively doubling it), giving you between 140 and 170 AH. Many RVers who have enough room will wire two 6-volt golf cart batteries in a series to increase their voltage to 12 and provide between 180 and 220 AH. If any of these options still don’t give you enough power, you can build bigger battery banks to satisfy your needs. You can wire them in series or in parallel to give you enough voltage or enough amp hours to power what you need.