Battery System in a Class A Diesel Pusher or Gas Engine Recreational Vehicle (USA)
The 12-volt house battery system is powered by a separate bank of ‘House’ batteries (typically 200 Ah to 1000 Ah capacity), which will be deep cycled regularly. The 12-volt system powers the DC lights in the living space, the water pump, hydraulic motors for slide-outs, and levellers and enables start-up of the water heater and furnace, which typically run on gas. The AC system is powered by ‘Shore Power’ or the generator and supports items like the stove, oven, TVs, and HVAC units. The battery bank can also power AC loads like refrigerators, microwaves and TVs through an inverter-charger. When the RV is plugged into shore power or the generator is running, excess AC power is automatically shared with the inverter-charger, and the 12-volt house battery system is recharged. House batteries need to support the surge current of the inverter during load startup. State of Charge (SOC) monitoring will be handy when ‘dry camping’ without shore power. Solar panels are often used to supplement batteries when dry camping and to provide maintenance charging during vehicle storage.
The starting batteries for a Class A Recreational Vehicle must consistently deliver high cold cranking amps, operate in high and low temps and withstand road vibration. With the engine off, High-Cycle Reserve Capacity is required to support dashboard electronics and GPS. The alternator is the sole charging source for the starting batteries.
Battery failure is most commonly caused by acid stratification, extreme temperatures and destructive over-the-road vibration. Acid stratification naturally occurs in flooded lead-acid batteries and leads to a decline in capacity and charge acceptance. AGM and acid mixing technology for flooded lead-acid starting batteries will mitigate acid stratification. AGM technology, or equalization charging by the inverter-charger for flooded lead-acid Deep Cycle house batteries, will mitigate acid stratification. Maintenance-free spill-proof batteries are highly desirable.