Why Does Your RV Battery Keep Dying? (How To Make It Last Longer)

An RV battery that drains quickly or doesn’t hold a charge can become a stressful chore, but does it need replacing, or is there another issue that may be fixed?

Whether your RV Battery is not holding a charge at all or is draining quicker than it should is an issue that definitely will not go away on its own. Motorhome RVs usually have two separate batteries, a chassis, and a house battery, which will cause different symptoms from one another.

If your RV battery does not hold a charge at all it is probably past its expiration date or has been damaged. If you’re certain that the battery is of good quality, but it is still being drained, there could be another issue like a bad converter or a power drain somewhere.

If your RV battery is not working the most likely scenario is that it is a dead battery at the end of its lifecycle and ready to be replaced. However, the issue could be caused by other parts of the Rv’s electrical system functioning incorrectly.

When I bought my vintage motorhome, I had to replace both batteries only to find out the electrical converter did not work. For me, the solution was as simple as buying a battery charger and using that instead.

‍What Are The Two Types of RV Battery

Motorhome style RVs will have one regular car/truck battery, usually referred to as the “Chassis battery,” as well as a deep cycle 12-volt marine battery, sometimes called a “house battery”.

If your RV is not starting and functions such as the gauges or radio are not turning on when the key is turned in the ignition, there is probably an issue with the chassis battery.

If functions on your RV, like internal lights or the water pump, are not functioning, then the deep cycle battery is probably at fault.

If your RV was exposed to cold weather for a prolonged time without starting, both batteries may be depleted of charge.

RV Chassis Battery Is Not Working

If you narrowed the issue down to the chassis battery, your RV most likely is not starting but other functions still work. In this situation, check the expiration date on the battery and visually examine the unit for corrosion or other damage.

If the battery is free from debris and within its expiration date, then it likely just has an insignificant charge left to power the vehicle’s starter. Some RVs have an “Emergency start” switch located on the dash that draws power from the deep cycle battery to the chassis battery. If this function is unavailable, the Battery can be charged with jumper cables and another vehicle, just like any car.

RV Deep Cycle Battery Is Not Working

If the house battery of your RV is not functioning, the most likely culprit is that the battery has been drained empty. These 12-volt batteries are specialized to be charged and drained regularly with a long lifespan, usually around ten years.

If functions like the water pump on your RV are not powering on, consider checking the battery's charge level. While a single deep cycle battery may last up to a week of regular usage, it will need to be charged before too long.

The deep cycle battery should be connected to an electrical converter (not an inverter) that allows the battery to charge when the RV is plugged into a power receptacle. If you find that your RV battery is continually dying with regular use and not recharging the issue may lie in the converter.

Why Would an RV Battery Keep Dying

RV Battery Is Dead

The most likely issue is that your battery has simply been depleted of the charge that it carried. This can happen in cold weather if the Battery connections are loose, or because of a damaged converter or alternator.

How To Know If an RV Battery Is Bad And Needs Replaced

If the RV battery is not registering on an external battery charger, check to see if the battery is out of date. If the battery is within its expiration date, examine it for visible water damage or signs of corrosion. If any of these symptoms are present, the battery may need to be replaced with a new one.

How Much Power Does An RV Battery Hold

One single deep cycle battery won’t necessarily last very long for a whole family or as a primary source of power. These batteries’ jobs are to power small appliances like the water pump and interior lights when the RV is not plugged into a power source. If you are drawing power from the deep cycle battery to power a TV or other appliances, the charge may not last past a day or two.

RV Converter Not Working

If everything should be working perfectly but is not, the issue could lie in the RV’s power converter. This is an electrical component usually installed close to the breaker box and if functions in the opposite way as an inverter.

The converter should be taking power from an AC source and converting it to a DC current to charge the RV batteries and maintain their charge levels. If otherwise healthy batteries are functioning for a long period of time until the charge dies out this is the most likely issue.

How To Make Your RV Battery Last Longer

Replacing An RV Battery

The first solution to a bad battery is to replace it. Car batteries do not last forever and at one point the battery will not charge and become dead weight. If your battery is damaged or past its expiration date it may be time to head to the store and replace it.

Most batteries will have a warranty of a year or two. While unlikely, it is possible to buy a bad battery new from the store. Even if your battery is brand new do not rule out that it could be damaged.

Adding Batteries To an RV

If one single deep cycle battery doesn’t last long enough for your needs, consider buying additional batteries. These can be hooked up together with the original house battery, or installed separately. The choice to connect batteries in serial or parallel connections will depend on your power needs.

Adding additional batteries to your deep cycle battery may be difficult and require the work of a certified electrician. Connecting a few batteries separately and using them as deep power storage might be an easier solution that only requires a charge controller and possibly an inverter.

Charging an RV Battery With Solar Power

Solar panels are becoming amazingly affordable lately. For only a few hundred dollars, you can invest in a full solar system and harness energy from the sun for free to charge your batteries. A solar array is a modular investment, and most of the components will last a long time. Old panels and batteries can be used in conjunction with an upgraded array.

Many RV goers install a solar system with its own battery array and then use that stored power to recharge or maintain charge on their deep cycle battery. This is a great way to add extra power to your RV without gutting and replacing the entire electrical system. The RV power plug can be plugged into the solar inverter and used as AC power.

Is AC Power Necessary For an RV

Another easy solution to power issues is to plug into AC if it is available.The truth is that most RV batteries are not designed for heavy or constant use, or to be used as a primary source of power. If you plan to live in your RV full time your chassis and deep cycle battery should only be used for their primary functions. AC power or an adequate solar array are only viable options for RV living.