RV Batteries Wiring Diagrams RV Batteries Wiring Diagrams for Series & Parallel connections An RV battery is a collection of lead-acid cells When connecting two 12 volt batteries in parallel, the voltage stays the same but the battery bank will provide electricity longer while maintaining a usable voltage. Campervan and Motorhome Electrical systems - Build a Campervan This section of the site looks at the various motorhome electric systems available, the electrical components, the electrical installation, campervan batteries, battery 12 Volt Electrics. - Deep Red - A self-build motorhome This will charge the leisure batteries from the campsite mains supply in the event the solar panels are not producing sufficient charge. The mains charger can be permanently wired to the leisure battery, however we have left ours 'loose' so it can also be used to charge a battery away from the van. Schematic Wiring Diagram Charging setup for 2 leisure batteries | MotorhomeFun Most of it is overkill for a two battery motorhome setup, but for emergency vehicles and marine applications, it's the place to be. Anyone with 3 or more batteries needs to read that site, even if they don't put it all into practice.