Why Is My RV Battery Boiling? (Causes and What To Do)

Did you forget something? This is often the case with the fun-filled days of RV living. Many owners tend to forget to check the levels of their batteries if they are not maintenance-free devices. This can cause you serious problems if you do. A bad smell and boiling are the results if you forget to regularly check your batteries.

There are several legitimate reasons why a battery will boil. One of those reasons is that you overcharged it. There could be a dead cell inside that contributes to this situation. Another reason is that you forgot to refill the battery cells with water.

To learn more about this important topic, just continue to read our article. It is filled with the information you need to know about if you want to avoid a boiling battery. Take a few minutes to see how this information can help you save your battery and extend its life.

Why is My RV Battery Boiling?


There are 4 good reasons why your battery may be boiling. Here are those 4 reasons:

1. You did not refill the battery with water- battery cells need water to stay cool. When they do not have enough water, they can get too hot and then start to boil the water.

If the battery cells are not cooled, they can fry themselves due to the excess heat.

2. Over-charging- too much power can be too much for any battery. When you overcharge those cells, you are giving them heat for an extended period of time. That extra heat can cause boiling and damage to your battery.

A faulty regulator can create excessive heat inside your battery boiling the water as a result.

3. Heat- when your RV is out in the sun too long and the outside temperature gets very hot, your battery can get damaged and boiling will occur.

This situation is a combination of events that brings the battery area to over 220 degrees F.

4. Over-use- this is when you are using only one battery to supply power to multiple systems. The discharge in this situation creates an overheated battery which can start to boil the water.

If you have 2 batteries in the bank, and they are mismatched, one could overcharge while the other could severely discharge. The latter would have to be recharged before you start your RV.

RV Battery Boiling When Charging


This can occur when you accidentally overcharge the batteries. When your voltage is, for example, above 13.9 volts, then hydrolysis occurs and the water inside the battery begins to boil.

Or, you have a dead cell in your battery and do not know it. The charger keeps on charging all the cells overheating the dead one. This causes the temperature inside the battery to rise and you get boiling.

Then you could have a defective charger. This happens a lot more often than you would think. The defective charger can overheat the cells by applying too much power to them.

Or it can just continue to charge even after the cells have the proper amount of volts. Either way, the water inside the battery will boil and you will have to take steps to cool the battery down and see if it will still work for you or not.

What Causes Battery Water To Boil?


As you have just read, there are a lot of sources for this issue. Some sources are avoidable while others are not. Here is a short list of sources to help you watch the conditions your battery faces:

- heat- this is a combination of the sun, battery case, and possibly engine heat. Once the temperature gets too high in your battery area, the water can boil

- battery drainage- too many appliances are drawing power from the battery. This causes a large discharge, damages the cells, and causes the water to boil.

- no ventilation- battery areas can be compact leaving little to no room for air to move about. You need a larger area for your batteries so the air can flow through keeping your batteries cooler.

- plate short circuit- this is where the battery has a cell that becomes faulty. That removes 12volts approx from the total needed to keep the battery-powered. When you go to recharge the battery, the 14 volts you use send too much power to the remaining cells which cause an overheating that boils the water.

What To Do If The Battery is Boiling?


There are as many solutions as there are sources for boiling water in your battery. For the last problem in the previous section, you need to check the voltage in the battery before you start to recharge it. Then add water.

For the no ventilation source, you just need to create a larger space for the batteries to let more airflow through the area. Or ventilate the current area better.

If the batteries are draining due to misuse or too many appliances connected to them, then remove different systems and appliances to save your battery. Then recharge it before the voltage drops to low.

When it comes to the heat being the source, you will have to cool your batteries down first before recharging them. You need to get the temperature in the batteries and area below 122 degrees F.

Finally, use a multimeter to monitor your charger and shut it down if it is overcharging your battery.

Some Final Words

Batteries boiling is not a rare event. It will happen to many RV owners because there is a lot of power being used at one time. Or there is a problem with the battery.

Keep an eye on the battery area and make sure they remain well ventilated to stop a couple of the sources from ruining your batteries. Also, check your charger regularly for any defects that may cause this problem. Having a multimeter on hand is a good idea as well.

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