- by Bryan Veldboom - updated on 5/22/2024
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 as deep-cycle batteries, and if you use them interchangeably, you could drastically shorten the life of the battery. This article will help you understand the different types of RV batteries and how they should be used.
Deep Cycle Batteries - A deep cycle battery functions as the "house" battery on an RV. These batteries are 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. Learn all about deep-cycle batteries in our recent article "What is a deep-cycle battery?".
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 in place of a deep-cycle battery.
Dual Purpose Batteries - Dual purpose batteries offer the best of both worlds, a starting and deep cycle battery in one. They can provide the initial burst of power necessary to start your engine and provide the long-lasting cycling power required to operate your onboard electronics and appliances.
In addition to the three 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 the battery you choose will have a major influence on how long it will last, how fast it will recharge and other aspects of performance. Here is a breakdown of the different chemistries.
Depending on the amount of electronics and appliances in your RV, you may require several batteries to power it all. Smaller RVs with few battery-reliant appliances onboard may be able to rely on a single starting or dual-purpose 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 several deep cycle batteries.
Don't mix battery types. You can use a dual-purpose battery for a starting battery and deep-cycle batteries for the home power but don't have a mix of dual-purpose and deep-cycle both powering your appliances. This is not a good practice for battery health.
Something else to take into account when determining how many batteries you need is how many Amp-hours (Ah) you need to run all of the appliances in your RV. 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, it's time to talk chargers. While your alternator will charge your RV's starting battery as you drive, you will need separate chargers for your deep-cycle batteries to keep them topped off and healthy. Our selection of marine battery chargers can also be used for RV deep-cycle batteries.
Still have questions? No problem! Stop into your nearest Batteries Plus and ask your questions face-to-face, or visit our blog has plenty of additional information to help you make an informed buying decision. Some related topics include "What Does 100Ah Mean on a Battery?", "How to Maintain Your Boat or RV Battery Over the Winter" and much more.