- by Bryan Veldboom - updated on 9/25/2023
When shopping for RV batteries, it's important to understand that specific batteries are designed to power different applications. Starting batteries do not function in the same way that deep cycle batteries do, and if you use them interchangeably, you could have a real problem on your hands. This article will help you understand the different types of RV batteries and how they should be used.
Starting Batteries (also known as cranking batteries) - Just like the batteries in your car or truck, RV starting batteries are built to deliver the short, intense burst of power necessary to start your RV's engine. They are not designed to provide long-term power and should not be used as a "house" battery.
Deep Cycle Batteries - A deep cycle battery functions as the "house" battery on an RV. The "house" battery is used to power appliances and other electrical systems when the RV is not connected to shore power. Unlike starting batteries that provide short, intense bursts of power, deep cycle batteries provide ongoing power for longer periods of time.
Dual Purpose Batteries - Dual purpose batteries function as both a starting and deep cycle battery in one. They provide the initial burst of power necessary to start your engine, together with the cycling power required to operate your onboard appliances.
In addition to different battery types, there are also three different battery chemistries available: flooded (wet cell) lead acid, AGM (short for Absorbed Glass Mat) and lithium iron phosphate (LiFePO4). The chemistry of a battery influences how long it will last, how fast it will recharge and other aspects of performance. Here is a breakdown of the different chemistries.
Flooded Lead Acid Batteries
Lithium Iron Phosphate Batteries
Depending on the amount of appliances on your RV, you may require several batteries in order to power it all. If you have a smaller RV with a minimum of battery-reliant appliances onboard, you may be able to rely on a single starting battery. Most RVs, however, will require a starting battery and at least one deep cycle battery, or a dual purpose battery either by itself, or paired with a number of deep cycle batteries.
Calculating the total power (in amp hours) that your appliances require per day will help you determine the size and number of batteries you need. Here is how to do that:
Once you have your batteries picked out, let's talk chargers. While your alternator will charge your RV's starting battery, your deep cycle batteries will require a separate battery charger. Our selection of marine battery chargers can also be used for RV deep cycle batteries.
Still have questions? No problem, our blog has plenty of additional information. Some related topics include "What Does 100Ah Mean on a Battery?" and "How to Maintain Your Boat or RV Battery Over the Winter." Or, stop into your nearest Batteries Plus and ask your questions face-to-face.