Why Did My RV Battery Overheat?

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RVs, or recreational vehicles, come in a variety of shapes/sizes. Regardless of whether you buy from a manufacturer or you make one from a converted van or bus, you must make sure that there’s a battery charging system. Otherwise, the battery can overheat.

There are several reasons for an RV battery overheating: lead acid batteries become more sulfated as they age, which results in more heating when charging. Lithium batteries not getting ventilation while charging can cause overheating. Any type of battery can overheat due to a malfunction in the charging system.

When you need power, overheated batteries are a hassle and- depending on the circumstances, an overheated battery could potentially be dangerous. In some cases, fires and explosions have occurred due to overheated batteries. In this article, we’ll talk more about overheating batteries and how to keep it from happening.

Why Does an RV Charging System Overcharge?

There are a couple of reasons why an RV charging system may overcharge batteries: converter malfunction and alternator failure.

Converter Malfunction

A converter transforms AC into DC power, allowing for battery charging in an RV. This is important to note when using an AC power source plugged into your RV to charge batteries.

If the converter is damaged, it won’t shut off when the battery is charged. This means that it continues to feed power to the battery. This results in overcharging, which causes the battery to overheat.

Alternator Failure

The second possible reason for batteries to overcharge is due to an alternator failure. In most cases, when you think of an alternator failure, you think about the battery not being charged- but the opposite also stands.

When the alternator is running over a certain voltage- typically 14.5 volts- batteries can become overheated.

Preventing Overheating of RV Battery

There are a couple of ways that you can keep your RV battery from overheating. These are:

Avoid overcharging

Make sure to have the alternator checked as part of your routine RV maintenance. You can have a mechanic check it or, if you feel qualified, you can use a meter to check for proper voltage from time to time.

If you catch an issue early on, it will keep you from having a problem when you’re trying to get settled on the campground. After all, if your battery fails when you’re off the grid like that, you will have no power.

Most converters do have a voltage control that turns off charging when batteries are full- you want to test this system at least once a month to make sure it’s working properly.

Make sure that lead-acid batteries have sufficient water. Keep distilled water on hand in case you need to add any. This will keep the batteries cool and avoid overheating.

Ensure Proper Ventilation

Most of the modern lithium batteries are made to shut off power when the battery begins to overheat. This is a great feature when it comes to safety. However, it can be exasperating when you have no power until the battery cools down.

Therefore, it’s necessary to make sure that you’ve got adequate ventilation and most RVs are made in such a way that batteries are kept col. However, most of the aftermarket and DIY battery compartments don’t have the appropriate ventilation.


When you know what causes batteries to overheat, you can take steps to keep it from happening. This will help ensure that your RV stays safe and so do you. After all, understanding the causes of battery overheating and making sure the system is properly maintained keeps things running smoothly. 

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