It’s important to understand the difference between starting and RV house batteries. House batteries are further categorized by the battery’s technology to store and provide power.

Starting (Motorhomes)

The starting battery in a motorhome is the energy storage device that provides power for the engine to start. Most solar panels batteries, like in passenger cars or other vehicles, are lead-acid-based 12-volt batteries.

This type of battery has been around for decades because of its specific ability to provide a large amount of starting (or cranking) power and then charge as the vehicle runs.

House (Deep Cycle)

As mentioned, an RV house battery (sometimes multiple batteries called a battery bank) provides power to the different electronic equipment associated with the living quarters of your motorhome, trailer, or camper.

The house battery powers the lights inside the RV, the refrigerator, power outlets, fans, and other interior items. A house battery might also power some exterior appliances. That includes an RV porch light, awning lights, the awning itself (if it has an electric motor), and other outdoor devices connected to the RV’s power source.

Despite the type of chemical make-up, an RV house battery should be of the deep-cycle variety. A deep-cycle battery provides sustained power over a long period. It’s better than a starting battery at being able to withstand being consistently depleted and charged.

Battery chemistry technology has a tremendous effect on the efficiency of a deep-cycle battery, how long it lasts, how well it performs, and how safe it is.

Flooded Lead-Acid

A flooded lead-acid deep-cycle battery is similar to the starter battery you’re likely familiar with in cars and other vehicles. The difference is that the deep-cycle version provides sustained power instead of the large amount of cold-cranking amps necessary to start a vehicle’s engine.

Though a flooded lead-acid deep-cycle battery does this and gets frequently used as an RV house battery, it’s no longer considered a highly efficient option. Flooded lead-acid batteries can only be depleted to about half capacity before the battery suffers irreparable damage that shortens its lifespan and reduces its effectiveness.

Flooded lead-acid batteries also require routine maintenance, which requires exposure to the gasses and acids within the battery. This can be dangerous if you’re not careful. These batteries also poorly handle the vibrations and jostling of RV travel and can put off hazardous gasses when damaged.

AGM (Still Lead-Acid)

A deep-cycle absorbed glass mat (AGM) battery bases its function on flooded lead-acid chemistry, but its build improves on the standard technology. AGM batteries still suffer the same depletion issues. But, being completely sealed, they are spillproof, don’t require routine maintenance, and are much more resistant to constant vibration.

GEL (Still Lead-Acid)

Gel deep-cycle, sealed batteries are very similar to AGM. They have a different technology that turns the fluid inside into a gel. It performs much the same as AGM but can handle deeper discharges a little better. But, AGM batteries handle cold temperatures better than gel batteries.

A gel battery is generally more expensive than an AGM battery.