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Why Does My RV Battery Keep Dying?

Batteries are the heart of most off-grid electrical systems, and RV’s all have batteries. These batteries provide power when disconnected from shore or when not running a generator.

Unfortunately, many RVers often claim that their RV battery keeps dying. Why does this happen? And how can you prevent it, so it doesn’t interfere with your trip? Let’s learn more.

Why Is Your RV Battery Dying So Often?

Proper maintenance is crucial to keeping your RV house batteries operational. However, your RV battery may keep dying even when you do everything right. Here are a few reasons why this might happen.

You’re Using a Lot of Power

If you’re not connected to shore power and run solely off your RV’s batteries, you could be using too much power. When boondocking, it’s important to conserve energy. RV batteries don’t last very long when you use every appliance and have plugs in every outlet.

Depending on your battery type using large loads even for a short period of time can limit output. Running a microwave on lead-acid batteries is not the same as lithium, because of the Peukert effect.

You’re Not Fully Charging Your Battery

Like overcharging, undercharging your battery can lead to sulfation — or the build-up of lead sulfate inside your battery. Undercharging can also cause shorter battery life or completely ruin it.

This is only a problem with lead-acid batteries as lithium is not damaged by undercharging. This is also why solar does not work as well on lead-acid batteries. Frequently, solar will not fully charge the batteries and can damage them.

fully charge batteries

Your battery should always be full before you store it. Both types of improper charging will lead to a shorter lifespan.

Pro Tip: Track your RV battery by Upgrading Your RV Battery Monitor. Find out how to DIY this easy upgrade!

You Need to Refill Your Battery’s Water

Flooded batteries need water to function correctly, and not having enough can damage it. The plates on your battery should never be exposed. Add distilled water before charging if necessary. 

This is commonly overlooked and is one reason many switches to AGM or lithium batteries do not need maintenance. Keep in mind that AGM is still a lead-acid type and will need to be fully charged and equalized ocassionally.

checking water level in flooded battery
Be sure to keep an eye on water levels in flooded lead-acid batteries.

Sulfation 

Sulfation is when lead sulfate crystals build up on the battery. This is quite common and almost inevitable, but you can slow the process with proper maintenance.

Mostly, sulfation results from overcharging, undercharging, or storing it above 75 degrees Fahrenheit. Sulfation can reduce the RV battery’s capacity and cause it to keep dying.

This is only a problem with lead-acid batteries and most of them will need an equalization charge that helps de-sulfate the batteries. This is a high-voltage charge that usually needs to be run manually.

Parasitic Loads

This sounds like your RV house battery has a parasite — and it does. Parasitic loads are systems that draw on your RV’s battery when not needed. 

You can’t completely avoid this, but you can eliminate the systems that drain power by using a digital multimeter. Use the device after turning off the ignition. Then determine what items are drawing power.

What’s the Lifespan of An RV Battery?

The lifespan will change based on the type of battery and maintenance. For example, if you have lead acid batteries and don’t fully recharge your batteries each day, don’t water them and never equalize them they will fail much sooner. In general, a lead-acid battery that gets used regularly in an RV will only last a year or two before it quits holding a charge as well. The type of battery matters, such as lithium versus a deep-cycle flooded lead-acid battery or a deep-cycle absorbed glass mat (AGM) battery.

But in general, a lead acid RV battery will last anywhere from two to six years. However, a neglected battery, even a top-of-the-line one, could only last a year.

Lithium batteries might last 20 years, but they also cost the most. Overall, lithium batteries do not require any maintenance or special charging to keep them healthy and are one of the reasons they last so much longer.

Lifespan also depends on if they are RV house batteries or starting batteries. Find out the difference.

How to Give Your Battery a Longer Life if It Keeps Dying

If you want to save some money and extend the life of your RV battery, there are a few things you can do. Your budget may influence what type of battery you buy, but the other tips merely require proper maintenance.

Interior of RV with battery
Extend your RV battery lifespan to extend your adventure potential!

Upgrade to Lithium

Lithium batteries last the longest, require the least maintenance and cost the most. They can even be fully discharged. Additionally, they recharge much faster. However, lithium batteries range from $700 to $1,600 each, so even with their advantages, most RVers can’t afford to buy two or three lithium batteries. However, if you can afford to upgrade, you’ll say, “My RV battery keeps dying” much less frequently.

We upgraded to lithium years ago and have never looked back. It’s one of the biggest upgrades we think you can make to your camper and will give you priceless peace of mind that your batteries aren’t going to die unexpectedly.

Pro Tip: We tested a bunch of RV batteries to find out What Is The Best RV Battery For The Money?

Don’t Go Below 50% (lead acid)

If you don’t have lithium batteries and don’t intend to upgrade, make sure you don’t go below 50% before recharging. You do need to get down to 50%, though. If you consistently recharge it above 50%, you actually reduce the battery’s lifespan. But if you allow the lead-acid battery to get below 50%, the internal resistance increases. Because of the depletion of electrolytes, the battery won’t hold a charge, and its lifespan will shorten.

Remove Corrosion

Over time, battery terminals will corrode. But you can prolong its life if you regularly inspect and clean it. Corrosion can drain power. 

Sulfuric acid, the chemical in lead-acid batteries, is highly corrosive. So you’ll want to look out for any build-up to keep it healthy as long as possible and reduce the risk of your RV battery dying.

Close up on battery corrosion
Battery terminals will corrode, so make sure to remove all corrosion to ensure it doesn’t drain your RV battery.

Proper Battery Storage

As mentioned earlier, your battery should have a full charge before storing. However, refrain from over or undercharging it to avoid sulfation. You also want to keep it in a cool place but not where the battery will freeze

Cooler temperatures slow down the rate of discharge while in storage. Because batteries lose a percentage of current through internal leakage, you’ll want to check the battery monthly.

Battery Tender When Not Used

A battery tender charges and protects it with extra safety features. It will stop the battery from charging, preventing overcharging and possible damage. 

If you camp in winter conditions, having a battery tender on hand can help protect it from freezing temperatures that will weaken your battery. 

You can also use a battery tender when you pull your RV out of storage. It will lose a percentage of current when not in use. This device helps prevent leakage and keeps your battery from dying.

Don't Waste Your Money On Batteries - The Shocking Truth I Discovered When Testing RV Batteries

When Is It Time to Replace Your RV Battery if It Keeps Dying?

If your RV battery keeps dying, you probably need to buy a new one. No one wants to go camping on a Saturday and then have the weekend ruined because of battery failure. If your battery is reaching the four to six-year mark, you probably want to go ahead and invest in a new one instead of waiting until it dies. 

As you regularly inspect your RV battery, replace it if you notice a lot of corrosion or damage. All of these things indicate that it will go bad soon.

So the next time you take your RV out for a camping weekend, check your battery. Make sure it’s in good condition.

When was the last time you checked for corrosion? Drop a comment below!

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About Tom Morton

Tom, a Pacific Northwest native, is our technical genius. Born in Washington and raised in Alaska before settling in Michigan. He's the man who keeps our operation running, both figuratively and literally.

With a background in Electrical Engineering, Tom specializes in RV solar systems and lithium batteries. He made history as the first documented individual to use a Tesla battery module as an RV battery. Tom has personally assisted countless RVers with system installations and has educated thousands more through his videos and articles.

Cinematography is another of Tom's passions, showcased in his work on the Go North series. You can see his camera skills on display in The RVers TV show on Discovery Channel and PBS where he also stars as a co-host.

Tom's mechanical expertise extends beyond RVs to boats, planes, and all things mechanical. He's renowned for taking on maintenance and repair projects single-handedly and is often spotted underneath RVs, making him the technical backbone of our endeavors.

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Ken

Wednesday 19th of October 2022

An excellent description of the science/chemistry behind sulfation in lead-acid batteries & how to minimize it.- http://www.bogartengineering.com/amp-hrs-based-charging-control.html

Raymond B Clark

Sunday 3rd of April 2022

My battery issue is different :( Thor apparently wired our class c bass akwards. When we plug in at a campground the truck battery goes dead. CW didn't want to fix it but finally looked at it during the pandemic when they got hungry. CW didn't fix it, they created a parasitic drain instead, when ever I stop now I need to disconnect or it will go dead in the time it takes to gas up :(

Mortons on the Move

Wednesday 6th of April 2022

That sounds so frustrating! :(