Here’s what to do if your RV battery is too hot!

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Taking a road trip is a part of American culture. Packing up the RV to hit the road with family and friends is a thrilling experience as you think about the adventure that lies ahead.

However, glamping in your RV comes with a set of challenges. RV’s require plenty of power to operate the electronics and electrical components in your mobile home. The battery in the engine bay of the vehicle only provides charge to the engine and RV electronics used in driving and operating the vehicle.

Your lighting, fridge, microwave, and any other lifestyle electronics receive power from deep-cycle lithium batteries. In most cases, these batteries can power your RV for days, especially if you have more than one battery in your power bank.

Unfortunately, batteries are prone to a variety of issues that may cause them to malfunction. One of the most common battery issues facing RV owners is a hot battery. You might think that it’s normal for batteries to get hot during operation. 

Sure, your battery might get a little warm after a few hours of operation.

However, if you check on your batteries, and find that you could almost fry an egg on top of it, then you’re dealing with an issue that requires your immediate attention.

Hot batteries can cause explosions, fires, and other health risks that can land you and your family in the emergency room if things go wrong. If your RV has a hot battery, here’s everything you need to know to handle the situation.  

If the battery in your RV is cooking, then it’s time to take action to resolve the problem. Start by disconnecting your RV’s power cable, and the battery charger. After the battery or batteries cool down, check the water level in the cells.

If the water level is low, then the battery charger could be charging your battery to death. Other reasons for heating of your battery include other appliances in the RV that are constantly drawing power.

If your heater or A/C is always on, then it may place stress on the unit, causing one or more of the cells to dry out, heating your battery.

Test the Converter

Another common problem causing the overheating of your RV’s batteries is the converter. The converter may experience a constant load, as mentioned above, causing it to charge the battery continually.

You could also have a faulty converter that’s overcharging the batteries.

Digital Multimeter

Purchase a voltmeter from an online retailer, and then use it to check the voltage readings on the converter. Your converter should read the output of 13.5-volts.

If you don’t have access to a voltmeter, then you can unplug the battery from the converter and the external A/C current, and see if the battery cools down.

Never leave a hot battery to keep building heat. If the battery gets hot to the touch, then it might explode, causing severe injuries to you and your family.

What If Only One Battery is Hot?

Those RV owners running a battery bank in their vehicle should ensure that they regularly check on the battery status. If you find that only one of the batteries is getting hot, then the chances are that it’s either a faulty battery or its expired, and you need to replace it with a new battery.

If you find that one of your batteries is going bad and overheating, then make sure you buy enough batteries to replace all of the units in your power bank.

If one battery goes, then the others aren’t far behind, especially if they’re from the same manufacturer brand.

After fitting your new battery, check it with your voltmeter to ensure it’s producing the right amount of charge. New batteries should display a reading of between 13.5 to 13.7-volts on your voltmeter. Those batteries issuing a reading above 13.8-volts are experiencing overcharging by the converter. 

If you leave your RV plugged in continuously, then disconnect the batteries to prolong the service life of the units.

When removing a hot battery from the RV power bank, it’s advisable to let it cool first. The smallest spark during the removal process may cause the battery to ignite and explode.

Is Your Battery Shot?

Misuse, abuse, and overcharging of the RVs batteries results in the reduced service life of the RV battery, and the eventual malfunction of the unit. If your battery gets very hot when charging, then the chances are that the battery plates shorted together inside the unit, resulting in a fault that makes the battery unusable.

If the plates ground together, then the charger reads the battery charge level as low and continues to charge the battery, even after its at full charge. The issue is that the RV battery no longer accepts the electrical charge, and the excess energy produced by the converter to the battery comes off as heat.

When taking your battery to a battery center for inspection, have the service agent check the converter’s output charging circuit. The reading you’re looking for should be between 13.8 to 14.0-volts. The current will eventually drop to 13.7 to 13.8-volts, which is the normal range for the battery and converter.

In the future, you must ensure that you limit your charging cycles to a few days in the month, or once every 2-weeks, depending on your requirements. 

Avoid keeping your power on continuously, and keep an eye on the water levels in the battery cells with a quick check once a month.

Sulfated Batteries

If your RV battery is getting hot, then it could be because of the sulfation of the unit. Sulfation describes the buildup of lead sulfate crystals in the unit, and it’s the primary cause of battery failure in lead-acid type batteries. 

Sulfation occurs in the battery when it does not get a full charge. As a result of the under-charging of the battery, the charge builds up on the battery plates. When the battery experiences over-sulfation, it impedes the conversion of chemical energy into electricity.

The sulfation of your RVs battery can lead to the following issues.

  • Extensive charge times
  • Severe heat buildup
  • Less output between charges
  • Reduced battery service life
  • A systemic failure of the battery unit

All lead-acid batteries are prone to sulfation, and all of them will eventually reach a sulfated state where the battery no longer performs its duties.

Sulfation is a natural process for the battery, but sulfation starts to cause issues with the battery in the following situations.

  • Storing the battery in high temperatures above 75F
  • Overcharging of the battery
  • Storing the battery without a full charge

Check Your Circuit

If you leave your RV hooked up to the electrical system, or you’re running a generator, you might find that your battery or batteries start to run very hot. In such a case, it’s probably due to a faulty battery temperature sensor.

Another cause of the issue could be the RV’s battery charger is distributing too high of a voltage to the batteries, or one of your batteries could be dealing with a potential short. If you do find the batteries getting overly hot due to overcharging, follow these steps to check for the cause of the problem.

STEP 1 –  Unplug the RV electric circuit from any external power source. If the batteries are boiling, then there is a chance they are running low on electrolytes. Top off all of your battery’s cells with distilled water. 

STEP 2 – After filling the batteries, ensure that all of the 12-volt lighting systems are off, and look at the battery monitor or control panel to check if the batteries show any charge.

STEP 3 – Plug your RV back into the external electrics, and check the voltage reading. If you get a reading above 14-volts, then the battery charger is overworking, and it could be the battery temperature sensor is faulty because it didn’t shut the charger down when the batteries started to boil.

If the reading from the voltmeter is lower than 13.5-volts, it’s undercharging your batteries. If the charger is working correctly, then try replacing the battery temperature sensor.

After replacing the sensor, leave the RV plugged into an external power source for at least 4 to 6-hours.

After a few hours, unplug from the external power supply, and check the batteries with your voltmeter to see if they are holding the charge. If your batteries are keeping the charge, they should display a readout of 12.6-volts on your voltmeter.

Wrapping Up: Get a Professional Inspection

Messing around with batteries and chargers when you don’t know what you are doing is a haphazard practice. Stay safe, and protect your family and yourself from injury by relying on a professional to do the job.

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