5 Steps On How to Charge an RV Battery With a Generator

The greatness of RVs is the ability to make you enjoy a home setting away from your houses. However, as you enjoy powering different electrical devices like lights and other small devices, the RV battery gets consumed up, and it can quickly lose charge. Whether it is at night or daytime, the thought of having a dead RV battery can be frustrating. It means there is no power even to start the RV unit should you need to move to another point. The question is How to Charge an RV Battery With a Generator?


There are different ways of charging an RV battery, including using an electrical AC outlet and hooking up solar panels. But what do you do in the absence of the two charging options? All is not lost! A reliable generator will help you charge your RV battery. Read on to learn how to recharge your RV battery with a generator and tips for preserving your RV battery charge, among other things.


Precautions to Observe When Charging Your RV Battery With a Generator


  • Use the correct charger for your RV battery.

The wrong type of charger might damage or destroy your battery’s cells and overall performance. Ensure your generator is running at its best performance by ensuring it has enough fuel to run for several hours without stopping or slowing down.


  • Avoid using your RV battery when it is charging.

This will reduce the life of the battery and lead to early damages or failures. Always keep your battery connected to the charger when it is not in use.


  • RV batteries will charge faster and last longer if you avoid draining them completely.

If your battery is almost drained, recharge it with a lower amperage to prevent overheating.

Rv Basic Tips Video 

How to Charge RV Battery With Generator

How to Charge an RV Battery With a GeneratorEven though generators are not made to charge an RV battery, some models come with leads and connections to support 12V battery charging. Here are easy steps to follow when charging your RV battery with a generator.


Step#1: Start the Generator

Before running the battery, ensure it has sufficient fuel to recharge your battery to the level of your expectations. Place the generator on a level surface, ensure it is several feet away from the RV, and power it on. Allow the generator to warm up, come to speed, and stabilize the voltage by allowing it to run for a few minutes.


Step#2: Connect the Battery Charger

As the generator is stabilizing its speed and voltage, work on connecting the battery charging cables to the terminals of your RV battery. Before clipping the battery terminals, ensure they are free from any corrosion. Check out for white, green, or yellow deposits around the terminals. If there are any deposits on the terminals, use an old toothbrush with wet baking soda to clean them. If the battery is not sealed, check whether it has enough electrolyte, you can add distilled water to the fill level.


Step#3: Disconnect all Plugged in Appliances

Unplug every electric device inside the RV, including switching off the light. Turning off the appliances when the battery is charging makes the battery recharge faster and efficiently.


Step#4: Connect the Battery Charger Into the Generator

At this point, the generator will have a stable voltage, and you can now plug in the battery charging cable into the unit’s 30A 120 volts outlet. Turn on the battery charger switch and inspect the charger’s status lights. If you are not sure how to interpret the status lights on the charger, refer to the user manual. Knowing how to read the status lights will help you to know when the battery is fully charged. Monitor the battery charging progress to avoid overcharging it. Overcharging an RV battery will adversely impact its performance and lifespan.


Step#5: Turn Off the Charger

Once the light indicator signals the battery is fully charged, switch off the charger and unplug it from the generator. Unclip the charger from the battery starting with the black (negative) clamp followed by the positive (red) clamp. Your RV battery is now fully charged.


What Size Generator Do I Need to Charge My RV Battery?

Any generator with an output of about 3,500 watts and 8 amp power can fully charge a 12 volts RV battery. However, if you want your RV battery to charge faster, you should go for a generator with more than 3500 watts output. But before plugging your RV battery into the generator, read the battery’s specifications to ascertain the compatible generator you can use to recharge it.


Some of the recommendable RV generators that you can use to charge your RV battery include:

  • Champion 3500 watts portable generator with a wireless remote function

An RV-compatible generator; it can power almost the entire RV unit. The generator has a starting power of 4375 watts and 3500 running watts, the standard requirement for charging an RV battery.

  • Champion 3800-Watt dual fuel RV ready portable generator

This versatile generator can run on propane or gasoline. The generator has a starting wattage of 4750 and 3800 running watts when running on gasoline. Propane which is a clean energy source, offers 4275 starting watts and 3420 running watts. You can use either fuel option to recharge your RV battery but for fast charging, use gasoline.

  • DuroMax XP4400E gas-powered portable generator

An RV-ready generator with a surge power of 4400W and 3500 running watts. This generator can handle heavy loads in your RV as well as charge your RV battery though independently.

There are many portable generators that you can use to recharge your RV battery; of essence is to confirm the compatibility of the generator to your RV battery.

Tips for Preserving Your RV Battery

ow to Charge an RV Battery With a GeneratorTo get the most from your RV unit, you must have a functional battery at all times. Here are easy tips for keeping your battery in the best shape:

1. Check Out for Corrosion

ow to Charge an RV Battery With a Generator

Corrosion hampers the conductivity of power from a battery. It causes a loose connection, and this affects the functionality of the battery. Any buildup of white, blue, or yellow matter around the battery terminals is a sign of corrosion. You can remove such deposits by use of a wire brush. You will need to put on safety gloves before you start the scrubbing.


2. Keep Your RV Battery Fully Charged Always

You should always aim at recharging your battery as soon as it loses charge. Most RV lead-acid batteries die because of small crystals (sulfation) formation on the plates, which occurs when a battery is in a low state of charge. The sulfation state begins when the battery reports a charge of below 80% or 12.4 volts. A fully charged battery has 12.7 volts. A battery efficiency drops by 20% when it registers 12 volts which is less than half a charge. A digital voltameter will help you keep track of your battery’s voltage.


3. Store the Battery in a Cool Dry Place

High or hot temperatures will discharge your battery quite fast than cool temperatures. RV batteries become weak during summer. To save the situation, avoid overcharging the battery and ensure adequate water levels in the battery cells. Check electrolyte levels frequently and add distilled water when the level is below the fill line.


4. Proper Maintenance

Maintain your RV battery by keeping it clean. Clean the terminals and inspect for any signs of damage or corrosion that might affect their efficiency and performance. If there is any sign of damage, replace the battery with a new one.


Why Would an RV battery Die?

An RV battery can die for many reasons. Some of these reasons include:

  • Having too many devices drawing its power
  • Overcharging and undercharging the battery
  • Having parasitic loads: These are devices that draw power even when they are off. A TV on standby mode is an example of a parasitic load.
  • Leaving the ground wire connected to the ground when the RV is in storage. Whenever the RV is idle, disconnect the grounding wire. Doing so will prevent it from discharging power to the ground when it’s not in use.
  • Self-discharge: This is when a battery stays in storage for an extended period. A battery can self-discharge about 10% of its charge monthly when it is in storage. If your RV is not in use, you can run it for about 8 hours a month. Doing so will recharge the battery and keep it in its best form.


Frequently Asked Questions

1. How long do I need to run a generator to charge RV batteries?

The number of hours your batteries will take before attaining a full charge depends on the size of the generator, whether there are appliances plugged in as the battery is charging, the number of batteries you’re charging, and the current level of your battery’s charge. Batteries with 20 to 30% charge can take up to 10 hours to attain full charge, while batteries with about 90% charge take a few hours to charge fully. A generator with more power output will charge your battery quicker than one with less power output.


2. Does running a generator charge an RV battery?

Yes. When you run an RV generator and connect it to your RV, it will power all connected devices, including your RV battery.


3. Why won’t my generator charge my RV battery?

How to Charge an RV Battery With a Generator

If your RV battery is not charging even after ascertaining the connection is okay, here is what you need to check:

  • The converter circuit breaker. Ensure the breaker is on and the fuses are in the best shape.
  • The breakers on the generator. Sometimes the generator’s breakers do trip; check if the breakers have tripped and restore them.
  • Condition of the battery. Check the electrolyte level and the wellness of the battery’s terminals. If the terminals are corroded, it may be impossible to recharge the battery.
  • Confirm the status of the connection. Recheck the connection and ensure the clippings are firm on the terminals.

If the situation is still the same after the above checks, consult a certified RV professional for help.


4. Can you charge a battery directly from a generator?

Yes. If your generator has a 12 volts DC outlet, you can plug in your battery charging cables and charge your battery. However, when making this connection, you must be careful not to overcharge your battery.


5. How often do I need to charge my RV battery?

ow to Charge an RV Battery With a Generator

You should charge your RV battery before departing for your RV trip. Once you begin to use devices that draw power from the RV battery, you should recharge the battery after about 20 hours of usage. This recharging duration is for a battery that is in perfect condition. However, for older batteries and defective ones, the recharging period may be shorter than 20 hours.


Final Word

Next time you are in the bush with a dead RV battery, power on your generator and allow the voltage to stabilize, connect the battery charger and ensure all devices in the RV unit are unplugged, connect the battery charger to the generator, and switch on the charger. Know when to switch off the charger and unplug the charging cables by monitoring the status lights. Practice the maintenance tips above for a long-lasting RV battery.

About Steve Stuart

Steve Stuart is an electrical engineer who developed interest on generators during his school years. After school, he became a generator enthusiast. This is after encountering power supply problems at the area of residence where he lived. Power would be on and off and so food would go bad and the room heater would go off especially during winter. After trying the different generator brands for several years, Steve now provides information on the available brands and products in the market today. Based on his experience, he gives the do’s and the don’ts when it comes to generator use.

Leave a Comment