RV Converter Draining the Battery

Having a converter in your RV is advantageous. Sometimes, you might be parking near a campground, and that provides an opportunity to take power from the grid and use it to top up your battery as well as power up your appliances. That's possible with the help of a converter to turn AC power from the grid into DC power that the battery can store. However, sometimes when you connect the converter to your RV, you might notice that your battery starts draining.

People’s first instinct is to blame the converter for draining the battery, however…

A RV converter cannot drain the battery as it does not require power to operate. All that a converter does is turn power from one current to another and does not need power from the battery to do that. If your battery is losing power then it’s probably because of a weak power source or the battery is faulty.

Below we will discuss the potential reasons that your battery is losing power and what you can do to fix it.

But first the basics!

What Does the Power Converter Do?

An RV power converter does just what its name suggests, convert power from one form to another. In this case, it takes AC power from the electrical grid and turns it into DC power for the RV battery to store.

Nowadays, campers can bring their home experience with them wherever they travel, thanks to sophisticated RV trailers. These cars have two independent electrical systems, a 120V AC system, and a 12V DC system.

Appliances such as TV, carbon monoxide detector, and lights consume less power and therefore run on the 12V DC system. On the other hand, furnaces, showers, microwaves, curling irons, and coffee machines typically run on the 120V AC system because they are energy-intensive. While the 120V AC system does not require charging, the 12-volt DC system contains batteries that must be regularly charged even while the RV is not in use.

While there are numerous ways to charge your RV batteries, the quickest method is to plug into a power source, such as a generator or a campsite electrical hookup. A converter helps convert the grid's or generator's AC electricity into a 12-volt direct current (DC), which the battery can store. If the battery is full and you want to save some for later, the converter also enables you to consume power directly from the grid or generator without touching the battery power.

A properly working converter does not drain batteries. If it seems the RV converter is draining the battery, it must be because of one of the following: power source not providing enough voltage, loose/poor connections, cooling fan not working, faulty fuse, dead battery, among others.

Troubleshooting an RV Converter problem

There are several approaches to identify the exact issue causing your RV battery to drain when connected to a converter. But you should purchase a multimeter or a voltage meter first to help with this troubleshooting.

These tools take various electrical measurements from the system to determine what's working correctly and what's not. In addition to calculating voltage, a multimeter can also measure amperage and wattage. Here is a detailed look at how to troubleshoot your RV converter draining battery problem.

Why Is Your RV Converter Draining Your Battery? 

The power source is not supplying enough voltage.

Before you suspect your electrical wiring and equipment, if you see that your RV converter is draining your battery, ensure you are receiving enough power from the grid. Sometimes, the power grid may be the source of the issue rather than your devices.

An unstable or inferior power source can bring about power spikes, surges, and cuts. Lighting that flickers, malfunctioning gadgets, and interfering with tv or radio reception are a few examples of problems caused by a poor power supply. Inadequate conductor wires supplying electricity to your trailer or network overload are some of the causes of poor-quality power supply.

Loose connections are another cause of inadequate power supply. It can involve your trailer or the electrical system. Connections are important when it comes to taking power from the grid. Your battery may occasionally not charge due to faulty trailer wiring, such as damaged converter cables, improperly connected terminals, etc.

In severe circumstances, a loose connection might result in electric shocks. Always ensure your RV wire connections are in good order and shape to carry power from the grid to your trailer. It is advised that you change the cables right away if you discover a problem.

Onboard batteries can't store charge.

Every battery has a predetermined life span. Your battery's lifespan is influenced by various elements, including its model, design, and maintenance practices. If you treat the battery well, it should last as long as the manufacturer says. However, even if you've followed best practices throughout, there will come the point when the battery can no longer retain charge.

The battery must be replaced in that situation because it has run out of life. However, before drawing such conclusions, you must first test it. Sometimes the battery may simply be so depleted that the converter struggles to charge it. In such a case, it might take time for the battery to start charging. However, this is rarely the issue; in most cases the batteries are just dead.

Batteries that lose significant charge when left idle for a short time, e.g. a day or two, are typically damaged or approaching the end of their life span. You may check to see if yours can hold charge by fully charging it, unplugging it from your trailer, and then allowing it to sit idle. If you test it later and see that the charge has dropped considerably, your battery is defective. The typical deep-cycle battery should live for roughly five years, although some last shorter than that for various reasons.

Additionally, you can check the battery for leaks. Due to the seasonal use of trailers, RV batteries frequently go unchecked. Consequently, the battery may get cracks, broken terminals, etc. Such things are important to watch out for because they can help you decide when to get a new battery.

However, if the meter shows your battery holds a charge well, but when you hook it to a converter, it starts draining, you should check it for problems.

Faulty converter devices

It's possible that a specific converter device developed a fault, leading it to drain your battery rather than charge it. Check your DC and shore power breaker box first. Your RV converter may not be working properly if the electricity reaching it is below the acceptable range. Inspecting the RV circuit breakers is another technique to evaluate your converter. To conduct the test, you must turn off the mini breakers while leaving the main one on.


To check if power is being delivered to an intended location, simply open and close the section's breaker. For instance, if you are experiencing problems with the interior lights, open and close the breaker for those lights. If you don't get the lights back after opening the breaker, then you have a faulty converter. 

Converter overheating brought on by a broken cooling fan.

To keep converters from overheating, they have built-in fans. These fans turn on and off based on a converter's internal temperature. However, in the case of a broken fan, the converter will just get too hot. You can check this by taking the meter reading at the point where power enters the fan.

If the fan is not running within acceptable AC voltage levels, something is wrong and may have to be replaced. When replacing converter fans, always get the same as the previous one. Converter fans are built for specific converters, so don't make the mistake of getting a different one. But if you have to get a different one, please ensure it uses the same amperage and voltage.

Even if the fan works properly, you should monitor the converter's temperature. Sometimes the temperature sensor might be to blame, especially if the fan is working properly but the converter is overheating. Take meter readings on both sides of the sensor. If the power reading is outside the acceptable range, then the sensor is not working correctly.

Defective fuses

Fuses are little electrical parts that are interspersed throughout the electrical circuit. Fuses are made to blow anytime there is a power sag or surge to prevent the faulty power supply from damaging your equipment or electrical wiring. You can begin by checking each fuse within the trailer. Your electrical system may be having trouble functioning because of a burned fuse. Do not delay if you see a damaged fuse. Replace it immediately.

A spare set of fuses should always be kept in your toolkit. Trailers use various amperage fuses. You can obtain them singly or in sets. Kits with blade fuses  are color-coded to make it easier for you to identify the right fuse for a particular amperage.

Circuit board corrosion by battery acid

Battery acid might collect in several connections on the circuit board, causing the converter to misbehave. You'll have to unscrew it to check. If you see a white, crusty residue on the board, it's time to clean it. First, check that your camper is not connected to any electrical system.

Next, prepare a solution of baking soda in water and dip it in a cloth or q-tips, then use it to wipe the residue away. Avoid oversaturation of the cloth/q-tips. You don't want to drown the circuit board. Once you are done, allow the board time to dry before putting it back and hooking up the power source. If there's no change, it's probably too corroded, and you'll need to replace the whole converter.

Battery acid buildup on resistors

Resistors are used in some trailer converter circuit boards to regulate voltage. You can find your converter's resistors hidden below the circuit board. They usually have gates, i.e., connection points, and in case of battery acid buildup at these gates, the converter won't work correctly.

These resistors are nearly tough to change on your own. It would be best if you took the trailer to a specialist. They can tell you whether the right thing is to replace the resistors or get a new converter.

Faulty diodes or resistor

Diodes to make sure that current flow is unidirectional. Resistors control how much current flows through a circuit.  If either are defective, they may be the reason your converter is misbehaving. A faulty diode might result in overloading circuits.

Sadly, even with an expert's help, they are challenging to test. The best course of action is to get a new converter if you find a problem with the diodes.

Solar Panels 

If you have solar panels powering your RV, is it possible that they are draining your batteries at night or while idle. Check out our full explanation here

RV Converter and Battery Best Practices

You may take a few precautions to maintain the condition of your converter and battery to prevent unnecessary power loss. Keeping batteries charged helps avoid sulfation which is the main cause of early battery failure. To avoid sulfation buildup, your RV battery shouldn't be drained over 50% of its capacity. You can top off your battery when necessary using green technologies (wind and solar power), alternator charging, generators, or shore power. You can also bring it home when not in use to practice trickle charging.

Storage is important, too. If you want to park your RV somewhere for the winter, think about removing the battery and bringing it home with you. RV batteries contain liquid, and low temperatures are especially harmful to them.

Store your RV batteries in a cool, dry place and test them monthly to ensure the charge hasn't dropped below 80 %. When batteries begin to self-discharge, recharge them.

Always check converters to ensure they are in working order before a journey. Older trailers should be inspected more often. Wear-and-tear problems, fuse replacement, and circuit board cleaning are common and necessary tasks. Remember to disconnect converters, too; if you are not charging your battery, overcharging batteries reduces their capacity to hold the juice.

Finally, before connecting your RV to an electrical outlet, always double-check that it is secure. You can use a polarity tester to check whether it's okay to plug in; otherwise, your electrical appliances could end up fried.

Power surges can harm electrical gadgets too, so it's a good idea to invest in RV surge protectors. Safeguard your electronics so they can last a long time.

That's all, folks. We highly recommend you check here for further information on all things RV batteries.