Will RV Converter Work Without A Battery: The Best Answer

When you are connected to shore power and do not have an RV battery, will your RV converter still give you DC power? Most RV converters will work without a battery. The converter will continue to take the 120v ac from shore power and give you the 12v dc power you need.

Although your RV converter will work without a battery, there are some things to consider. In this post, we will review what will review:

  • How does the converter work with the battery
  • How does the converter work without a battery
  • Issues by not having a battery with your converter

Even though your converter will operate without a battery, there are drawbacks that you should know as an RV owner.

Table of Contents

How Converter Works Without Battery

Your RV converter takes 120v ac shore power and “converts” it to 12V dc power. This is extremely handy because, unlike your house, your RV does use quite a bit of 12v battery to operate dc appliances:

  • Lights
  • Water Pump
  • Furnace Blower
  • Slide Out

So without a converter or battery, you would be unable to function things in your camper, such as lights or slide out.

Converter With Battery

The converter will act as a charger when you have a battery with your converter. It will continue to give the RV battery dc power to keep it fully charged. Whether you have deep cycle batteries, AGM batteries, or even lithium batteries, the converter will give the power needed to charge and extend battery life.

Once the battery is fully charged, usually around 14.4V, the converter will turn off and stop charging since there is no need. Have you ever heard the fan going at your breaker panel? That is usually the fan that dissipates the heat from the converter. Since converting ac power to dc power makes heat, the fan is needed; otherwise, the converter would overheat and shut down.

A converter has three modes of charging a battery, and they include:

Normal Mode. This is the mode where the converter provides 13.6v of power to the battery to keep up with the demand of the appliances. As you use your battery, this mode keeps the battery maintained and fully charged to keep up with the demand of the RV.

Charge Mode. This mode senses that the battery is not fully charged and will not keep up with the demand. The converter goes in this mode by switching to a boost in voltage and giving the battery 14.4v so it can charge and keep up with the demand of the RV.

Trickle Mode. This mode sense that the battery is fully charged, and no appliances or lights are used in the RV. In this mode, the converter drops to a low 13.2v to keep the battery at full charge. Since there is little to no load, there is not much need for the converter to work so hard.

Converter Without Battery

Without a battery, your converter works similarly, just not exactly the same way. Your RV and converter are designed to get the dc power from the battery vs directly from the converter. With the converter connected to the battery terminal, it is meant to charge the battery. And for the power to be distributed to things such as lights from the battery itself.

Many appliances run on 12V in your RV

Without a battery, the converter directly provides the needed dc power to appliances. The converter will constantly run as it tries to keep up with the demand of converting the ac power to dc power.

As you read above, a converter has three modes and is designed to have the battery at some level to work with and keep up with demand. Without a battery, the converter is doing all the work to supply power which could lead to potential issues.

Issues For Not Having a Battery with your Converter

Above, we reviewed that a converter can work without a battery. Although it works, I suggest you continue without a battery for only a short time, and here are some reasons why.

Limited Power

You will have limited power and may be unable to run all your appliances. Your converter is more of a charger and gives your battery a trickle charge of voltage. Your RV battery has a reserve capacity and can provide hours of clean dc power to the needed appliances. And with the converter charging the battery slowly, it doesn’t have to work as hard to keep up with the voltage demand.

Blown Fuse

With a constant demand from your converter, you run the risk of it overheating and blowing a fuse. Since it was not designed to run at full capacity all the time, this could overextend the converter and cause it to overload and blow fuses. For more info, visit RV converter fuse location post.

Converter Life

Your converter was meant to be more of a battery charger. And when used as designed, it turns on and off as needed only to give extra charge to a battery. When the converter is used for all of the dc power needed, it will run continuously to keep up with the voltage demand for dc appliances and lights. This continuous running will shorten the life of the converter and likely cause it to need replacement sooner than expected.

Fan Noise

Have you ever sat in your RV on a quiet day and heard a fan going? You look around and don’t see any fan or appliance, so you wonder where it comes from. Likely, it is coming from your converter.

Heat is produced when your converter operates, and a fan will constantly operate. This fan will continue to run since the converter is constantly giving off heat trying to keep up with the voltage needed.

No Back up Power

Shore power is great, but if something happens and you don’t ac power? Without a battery and relying on the converter, you will have no power options for your RV. When you have a battery connected to your RV, at least you can operate your lights and even your furnace in an emergency. Even with LP gas, your furnace will not operate. For more info, visit will my RV furnace run on 110 post.

Void Warranty

Flipping through many converter owner manuals, the system is designed to use a battery. By not using a battery, the manufacturer could claim that the product was misused, and there could be a warranty denial.

Manufacturer suggestions on using a battery

Here are the written suggestions from Parallax, a converter manufacturer. There is a whole section on the need for a battery and how it should be maintained with its converter. Not connecting batteries allows the manufacturer to note misuse and a possible rejection in a warranty claim.

Final Thoughts

While connected to shore power, running your converter without a battery is possible. The converter, like a battery, provides DC power and can run appliances such as lights. However, you need to be aware that this is not how most converters were designed to operate. Not using a battery exposes the converter to issues such as reduced life, excess heat, and even a chance of being denied a warranty claim.