No matter how well you take care of the batteries in your RV, you’ll eventually need to replace them. We’re here to help make sure you end up with exactly what you need.
Recreational Battery Buying Guide

Why Do RV Batteries Fail?
There are plenty of reasons why your recreational vehicle battery might need replacing. Interior corrosion, for example, can lead to failure. Leaving the battery at a low state of charge, connecting it incorrectly, or using the wrong type of charger can also cut its life short.
Even extremely hot or cold temperatures, which aren’t uncommon throughout most of Canada, can cause a lead acid RV battery to fail. You should keep this in mind if you spend your winters somewhere warm, like Arizona. Excessive vibration from driving on rough roads can reduce the lifespan of the battery as well.
That said, the two main reasons why starter batteries, deep cycle batteries, marine batteries, and even absorbed glass mat (AGM) batteries will fail after a few years are sulfation buildup and paste shedding.
Sulfation and Shedding
Sulfation happens naturally when sulfates in the battery acid crystalize on the lead plates. Over time, this process causes the sulfate levels in the liquid electrolyte to decrease, reducing the battery’s ability to hold a charge.
Paste shedding is caused by natural expansion and contraction. It refers to the shedding of lead paste off the plates in the battery. As the plates lose lead, the battery loses power.
Replace Batteries in Pairs
Lots of RVs, especially bigger ones, have more than one battery. If yours does and it’s time to replace one, you should probably replace them all.
Yes, replacing multiple batteries can be expensive, but think about it this way: the other batteries have also been affected by whatever caused the first battery to fail, so they’re probably close to failure as well.
If you replace only one battery, it might get damaged by the others since they aren’t at a hundred percent, which means you’ll need to replace it all over again—along with the rest.
Unless the single battery that failed is still under warranty, it’s probably time for a whole new set.
Check Your Voltage
Most recreational vehicles use 12 V lead acid batteries, but some have a 6 V battery. Two 6 V batteries connected in parallel amounts to 12 V, but with potentially more amp-hour storage. Make sure your replacement battery has the same voltage as the old one.
House or Vehicle Battery?
Many RVs have two different electrical systems with two different types of batteries: house batteries and the truck battery. The house batteries are used to power electronics in the RV.
House batteries are usually deep cycle 12 V batteries. They’re long-lasting and capable of deep power discharges—exactly what you need for a couple of days of off-grid camping.
The truck battery is going to be a starting battery. These are batteries designed to be able to put out lots of power for the short time your starter is running. Then, your engine’s alternator takes over power and charging.
A truck battery is just fine being charged by the alternator. The charger on your deep cycle house batteries charges much more slowly. The two batteries can be switched, but doing so typically results in short battery life and other problems. You should also keep in mind that solar power charging is usually slow.
Battery Size
RV batteries, like all batteries, come in different shapes and sizes. We’re talking about physical size as well as the amount of power they can store.
Battery manufacturers follow standard battery dimensions called group sizes. The group size of your battery defines its dimensions, where the terminals are, and usually how much charge it can hold.
If you get a battery that isn’t the right size, it won’t fit in your battery box. It may not last long or hold a charge as long as the battery it replaced. Bigger isn’t always better, something you don’t want to find out firsthand while camping.
Battery group size is usually indicated on the battery sticker. If it isn’t, your local NAPA Auto Parts specialist can take a look and let you know what you need.
Chemistry Is Key
The chemistry of your RV battery is also important. Got a flooded lead acid battery connected to an AGM battery? That’s bad for your battery and your charger. Lithium-ion batteries, the type you’ll find in an electric vehicle, are starting to show up in RVs too. They need to be replaced with the same lithium batteries, not the lead acid type.
A Battery of Choices
As you can see, you’ve got plenty of choices when it comes to selecting a long-lasting battery for your RV. For more information, talk to a specialist at your local NAPA AUTOPRO service centre or NAPA Auto Parts store.