How to Store an RV Battery for the Winter

Storing your RV’s battery over the winter is a great way to increase its lifespan. There are several systems in your RV that run constantly and will drain your battery, and even worse – your battery can actually freeze if left attached over the winter.

To store your RV battery for winter first disconnect your battery, then top off the water and clean the outside. Charge it fully then store it in a warm and dry place using a trickle charger to keep the charge, and then just check the battery’s charge monthly.

No one wants to buy a new RV battery sooner than they have to, but the task of disconnecting and storing it may seem daunting if you’ve never tried it before. The good news is you don’t need to be a mechanic by any means, and I’ll take you step by step through the process of how to store your RV batteries for the winter.

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How to Store Your RV Battery

Should RV batteries be removed in winter months? I was skeptical at first myself. Winters are mild where I live and the likelihood of my battery actually freezing is almost zero. Having said that, I have stored my fifth wheel for some time in the past and I’ve learned that freezing weather isn’t the only reason to store your battery.

Your propane leak detector, for example, is one of several systems that are always running in your RV. When you’re on the go your truck or motorhome engine is recharging the battery so that you don’t notice the draw from these systems, but when your RV sits for long periods they will slowly drain your battery.

This can cause sulfation, or the buildup of small crystals on the battery’s plates. Sulfation starts when your battery’s charge drops below 80% and only gets worse from there. Sulfation will ruin a battery if it isn’t recharged promptly, so properly storing your battery before you store your RV will keep you from potentially facing a costly replacement down the road.

If you’re not like me and you do live somewhere with consistently freezing winters, you have even more reason to store your battery. RV batteries have a mixture of water and sulfuric acid in them in addition to the lead plates, and when temperatures drop below freezing that liquid mixture will freeze. As it freezes it expands, and this can cause the battery case to crack which will damage or ruin your battery.

Whether you’re preparing for a cold winter or you’re just taking a break from the RV life for a few months, hopefully you see how important it is to store your battery. Now you’re probably wondering how exactly to go about it. There are six simple steps to store and maintain your battery over the winter, and I’ll walk you through each one.

Disconnect and Remove Your RV Battery

The first thing you’ll want to do is to turn off everything you can that is drawing power from your battery, then use the owner’s manual to locate where your battery lives. Depending on your setup it can be in a number of different places, but once you’ve found it you’re going to want to identify the positive and negative terminals.

Ideally your RV battery terminals and leads should be labeled, but if they’re not then you’re going to want to label them before you remove the leads to make sure you can hook them back up properly down the road. 

There will be two wires (leads) connecting to your battery terminals, and they may be any combination of black, white, or red. White leads are always negative and red leads are always positive, so if your terminals and leads aren’t labeled then you can quickly mark them based on where each wire is attached and what color it is.

Now you can start disconnecting the battery. The leads will be attached by a nut and bolt so first you’ll need either a socket wrench or adjustable wrench to take the nuts off. Always start with the positive lead, removing the nut and then sliding the lead off of the bolt. 

Once you have removed both the positive and negative leads, you should be able to just pick the battery up or slide it out of the compartment. Many batteries will have a handle conveniently placed on top that you can grab. Once the battery is out you can cover the lead ends with caps, just make sure that you never let the exposed ends touch each other during the disconnection process. 

Clean Your RV Battery

Before you store your battery you’re probably going to need to give it a good cleaning. You’ll want to remove any corrosion that has built up as well as any dust or dirt on the battery casing. Corrosion will look like a white, greenish, or bluish buildup around the battery terminals and can add extra strain (resistance) to your battery circuit, while dust and dirt can get inside when you go to check your water levels.

You can use a mixture of baking soda and water in a 1:6 ratio to clean the battery casing by spraying it on and then using a rag to wipe it down. If there is any corrosion, you can also use that solution to spray it and then use a wire brush to scrape the corrosion off. 

Check Your RV Battery Water Levels

Now that you have your battery out and cleaned you’ll want to check the water level. RV batteries should contain about 36% sulfuric acid and 64% water, and through regular use the water level will go down. 

To check it, first put on a pair of gloves and some safety goggles. Sulfuric acid is highly corrosive and even a small drop can do damage to your skin and eyes. Using a flathead screwdriver, pry up the labeled covers on top of the battery compartment. This will expose a number of different holes (cells) going into the main compartment and you will be able to see the level of the liquid inside.

The liquid should be at least a half inch above the tops of the plates in the cells, so if the water level seems to be low you can top them off with distilled water. Don’t fill the cells up too much – just over that ½ inch mark – or you risk the liquid overflowing while your battery is operating. 

You also only want to use distilled water because it contains fewer minerals that will accumulate in your battery once introduced. Once the cells are full, put the caps back on and clean up any liquid that may have spilled in the process. Then you’re good to start charging the battery.

Charge Your RV Battery

Your battery is clean, full, and almost ready for storage. The last thing to do is to fully charge it. If you’ve been traveling recently your battery may already be fully charged, but if not then you’ll want to get it back to 100%. You want to store your battery with a full charge to make sure that it stays above that 80% mark while in storage, as it will slowly lose some charge while it’s not being used.

There are many ways to charge a battery from using the shore power at your home to using a 12-volt battery charger to using a generator, and the easiest way for you is going to depend on your setup and your battery size. Whichever way you choose, just make sure you use the right equipment and don’t overcharge your battery.

Use a Trickle Charger

Now you’re ready to store your battery for the long haul. If you’re only planning to go for a month or two without using your RV then you probably won’t need to use a trickle charger, but any longer and you risk losing too much charge from your battery.

A trickle charger senses when your battery levels start to dip and slowly recharges it. They are great for long-term storage because they will maintain your battery above that 80% mark and keep you from having to recharge it yourself, while also making sure to stop before the battery is overcharged. If you’re storing your RV for more than two months, a trickle charger is highly recommended.

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Check Your Charge

A trickle charger will tell you your battery’s charge, or you can test it using either a multimeter or a hydrometer. To use a multimeter you place the positive and negative leads on the battery and read the voltage readout. Anything lower than 12.4 volts indicates that your battery is at less than 100% charge. 

You can use the hydrometer by sucking out the liquid from each cell and measuring the specific gravity on the hydrometer. Anything lower than 1.235 indicates that your battery isn’t fully charged.

If you decide to skip the trickle charger, you’re going to want to check your battery charge at least monthly. Even if you do decide to use the trickle charger it’s still a good idea to check in monthly and make sure that there aren’t any malfunctions or other issues.

Where to Store Your RV Battery Over the Winter

You know you have to disconnect RV batteries when in storage, but you’re probably wondering where exactly to store it. If your RV is going to be stored outside in winter conditions I would strongly recommend bringing the battery somewhere warmer to make sure it doesn’t freeze.

This could be a garage, shed, cellar, or anywhere else that’s warm and reasonably dry. You don’t want to set the battery directly on the ground as it may cause it to lose charge faster, instead use a layer of cardboard or other material beneath it. 

You can also get a battery box to store it in that will keep the battery insulated and protected, just check and see if you can also use the box while the battery is hooked up to a trickle charger.

Closing Thoughts 

There are many benefits to storing your RV battery over the winter, but they all come back to increasing your battery’s lifespan. All you have to do is disconnect the battery, clean and fill it, charge it up, then store it away from the elements. You can use a trickle charger if you’re going to be away for a while, but just make sure it’s fully charged before you go to hook it back up.

Diane Dee

Diane is a lover of all things travel. She and her young family wanted to explore North America from the comfort of their own home so they bought an RV. After fully rehabbing a 1994 Safari Trek, they set out to explore both Canada and the USA.

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