Power Distribution
A typical off-grid power distribution system will use batteries to power an inverter, which powers all the AC loads. Determine the size of your inverter by the peak power demand of your RV. The more ruthlessly you cut your “must have” device list, the smaller an inverter you can use. We use a 3 kW inverter from Victron Energy.
When you power the entire RV with an inverter, it’s critical to include some sort of automatic transfer switch to control whether power comes from the inverter or the shore power plug and ensure that no power from the inverter can pass to the shore power plug.
Energy Storage
Off-grid success hinges on the battery bank. General wisdom says to buy the best batteries you can afford. Lithium-ion batteries are the gold standard for the modern RV. The real question is, how many batteries do you need? Battery capacity is quantified in Amp-hours (Ah). A perfect 100 Ah battery can supply 1A for 100 hours or 50A for 2 hours. Most RVs have a 12V DC system, so 12V batteries can be added in parallel to increase the storage capacity (Ah) rating of the array, which will increase the amount of time the batteries can operate the RV. Lithium-ion battery systems operate at 14.4V so we use 4 x 100 Ah Battleborn batteries to store the 5.76 kWh hours we need to keep our RV powered at night.
Power Generation
There are two main ways to generate power in an RV: solar panels and generators (gas or propane). We use a 6-panel, 960W solar array with a 2200W generator to keep the RV powered off-grid. Most generator-powered rigs use the generator to directly power all AC devices when it is running, which requires a 5 kW generator. We only use our generator to charge the batteries through a dedicated generator input to the rectifier. This allows us to use a much smaller generator and only use the inverter to power our devices. In addition to being convenient, it serves to protect our sensitive electrical devices from dirty generator power.