How to Charge Your RV Battery While Driving (+ Alternative Ways To Charge)!

How To Charge RV Battery While Driving

A dead battery should not stop you from having the time of your life while in your recreational vehicle. Fortunately, that is not a problem at all if you know how to charge it properly. Don’t get hit on the road by a low-charge battery and bring in back to life following simple steps. 

What You’ll Need:

  • Anderson Plugs
  • High-quality and high-amp cables
  • VCR (Voltage Controlled Relay)
  1. The first thing you will be doing is to set up the VCR. What this device does is that it disconnects automatically, make the auxiliary parallel and start the batteries. In the case of the connection you want to make, the VCR is closed when the batteries become paralleled based on the preset settings. The relay opens when your vehicle begins to run. When you turn off the vehicle, the two batteries will tend to stay disconnected. The batteries will then go back to the preset level.
  2. The high-quality and low-quality amps will be used to combine batteries. You will do this to minimize the risk of a voltage drop. We recommend you use high-quality Anderson plugs to ensure that the voltage loss is minimal while providing an excellent connection. These plugs are also useful for carrying large amperage. The automatic reset circuit breaker runs at 50 amps and provides circuit protection. This greatly reduces a fire hazard.Identifying this safety addition is fairly easy. The breaker is found on the positive lines on each side of the plug. Plus, you might also notice a few rubber boots slipping on the breaker. They are designed to offer insulation from shorting.
Alternative Method

As an alternative, there is a different way to get the job done. You just need to follow the following instructions.

  1. Disconnect the cable from the primary battery's negative post. Next, place the extra battery and use the tie downs for the purpose of holding the battery in placeIf you prefer, you can also use the existing bolts for an anchor while you handle the tie downs. You can alternatively use sheet metal screws to drill and then connect the tie-downs.
  2. Using a right size screw or bolt, connect the battery isolator. You can use a drill to drive one sheet of the metal screw to the vehicle's frame. It is important that the attachment is in the firewall of the engine's compartment.
  3. Locate the battery post that you can find at the alternator and trace a wire from there to the vehicle's fuse box. Note that the battery post is usually labeled "B" or "B+", making it easier to locate. Then connect this wire at the opposite end of the fuse box where you wired the alternator.Next, run it to a post with an "IN" label on the insulator. At the end part of the wire, you will find a ring. Your next step will be to strip and then to crimp this ring connector. This is a better alternative to coiling a bare wire to surround the post. This ring will provide a more reliable connection between the wire and the post.
  4. Connect a wire from the "OUT" post in your insulator and run it to your extra RV battery's positive post.
  5. Ground the mid post directly into your RV's frame. Do this by connecting a wire that attaches the middle battery isolator's post to a screw or bolt passing through your vehicle's frame.
  6. Starting from the extra battery's negative post, run a wire and connect with your RV's floor pan. Make sure you do this connection to the pan's metal part and not the plastic part. Next, connect the negative cable again to the vehicle's main battery.

How Long To Charge RV Battery While Driving?

This will ultimately depend on how depleted of charge the battery was in the first place. A depleted battery might be an issue because your RV will initially provide a high-charging rate but then it will stop when it detects that its own battery is fully charged. 

If this battery is completely depleted, shutting down will happen much sooner than you wish, leaving you with a partially charged battery.

Usually, trailers, trucks, and RVs have this shut-down function so that your batteries do not get more charge than what they need. If this is a fifth wheel you are charging, then consider that this new battery might be putting more stress to your entire charging system, meaning that they might require more than the usual time for charging.

That's not all...

Extend The RV Battery Life! ( Regular Battery Maintenance)

Besides knowing how to charge your battery while on the road, it is also important to know a thing or two about keeping your battery in optimal conditions. This is important in order to extend the life of your battery. The following are some tips on how to lengthen the lifespan of your battery:

Prevent sulfation

In order to prevent sulfation, you must keep your battery charged when not in use. When a battery sits unused for a long time in a low charge state, small crystals begin to form in the plates. This process is what we call sulfation. Give your battery regular maintenance to prevent this. 

Put OFF The Battery Disconnect Switch When You Are Not Using The RV Battery

Keeping the switch off avoids discharging. If a battery is discharged, then it might start sulfating. 

Avoid Hot Temperatures As Well As Overcharging

Overcharging and exposing your battery to hot temperature are two factors that will reduce the life of your battery. If it is too hot outside while the batteries are in use in your RV, make sure you monitor the cells’ water levels with more frequency.

Constantly monitor water levels and pour distilled water when needed. This will prevent damage to your RV battery, especially if it is a lead-acid type. 

Only water the RV battery after you charge it

Unless the plates are already exposed before you charge the battery, it is recommended that you water it only after charging. 

If the plates are exposed, pour just enough water to cover the plates and then charge it. After the battery is fully charged, fill each cell down to the vent’s bottom. 

Also Keep In Mind:

How do you store your RV battery the right way

Storing the battery the proper way is also important to keep it in optimal condition. If you are going to put your RV in the garage for a very long time, your battery will sit there unused for as long. This is why it is important to store it properly.

If a battery is left to idle unused for a very long time, it will self-discharge. This process will depend on the temperature and the type of battery you have. It is imperative then that you know how to store your battery properly. By doing this, you extend the life of your battery.

Before storing, charge your battery to 100%. Remove any corrosion, grimes, residues and always wipe dry the top of your battery. If the terminals are fully corroded, use an iron brush to remove them. Clean terminals ensure that the battery will not discharge and that there will be no discharge paths. 

Check the electrolyte levels and replenish with distilled water if necessary. Keep the water level at 90% since it will expand and you do not want it to overflow when you charge it. 

As with the temperature, store your battery in a dry place at a temperature not lower than 32°F (0°C) and not higher than 80°F (27°C). Never attempt to charge a frozen RV battery as it will surely explode. You also want to get sure that wherever you store your battery does not get flooded.

Make sure you check your battery regularly if you are not going to be using it for a long time. Recharge it at least once a week.  

Our Favorite Way To Charge!

How to charge RV Travel Trailer Battery Using A Generator

Before we proceed to charge the RV battery using one of the best RV generators on the market, it is important to inspect the RV battery and the electrical system. Do this to ensure that your RV won’t get damaged or you do not get harmed. Also, ensure that the battery is safe before handling it.

Follow these steps to effectively charge a battery using a generator:

  1. First, you must make sure that your generator is fully charged or that it is connected to an AC outlet.
  2. Turn off your RV and make sure the emergency brake is engaged.
  3. Inspect the batteries and check for corrosion, cracks, or bulges. If everything seems fine, proceed to step #8. Go on to the next step if you find that your battery terminals are dirty.
  4. Remove the cables using a wrench before cleaning the terminals. In doing this, remove the negative (black) cable first and then the positive (red).
  5. Remove the cables using a wrench before cleaning the terminals. In doing this, remove the negative (black) cable first and then the positive (red).
  6. Prepare a paste with baking soda and water. Apply this paste to the terminals using a toothbrush. To remove the corrosions, use a wire brush. After removing all the grime, wipe it off with a cloth and make sure they are dry. Protect the terminals by adding petroleum jelly or battery rust protector to them.
  7. Check the electrolyte levels in the battery. If they are low, add distilled water up to the fill point.
  8. Reconnect the RV battery. Connect the positive (red) cable first and then the negative (black) cable. Securely fasten them using a wrench.
  9. To maximize charging, make sure all electric appliances, including the lights, are turned off.
  10. Make sure the generator is plugged into a 120-V AC outlet, if applicable. Otherwise, make sure the generator is fully charged. In this case, consider that charging will be rather slow and it might not fully charge your RV battery. The charging will also depend on the temperature. You may not get full capacity if the temperature is below 40 degrees Fahrenheit.
  11. Plug your RV battery into the generator. If your generator is plugged into an AC outlet, it will take approximately two hours for your battery to charge. It will take longer if your battery has fallen to 20% of its charge.
  12. Mind the proper use of your electrical appliances after charging your RV battery with a portable generator until you get to campground. Plug your portable generator for future use as soon as you can.

How To Charge RV Battery From A vehicle

If you have jumper cables with you, your vehicle can charge your batteries for you. It is part of the essentials you should always carry with you. But if you do not have one, you might need to ask a generous neighbor to lend you a set. Once you have them, you are ready to charge the RV battery from the vehicle.

Follow these simple steps:

  1. Check your battery connections before attempting to charge your battery to rule out any loose connections. This can make your battery appear dead when in reality, it is fully charged.
  2. Make sure you park your car very close to your recreational vehicle. Your car must stay running for the following steps.
  3. Turn off all electronic accessories and lights in your RV before starting the process of charging your battery.
  4. Open your car’s hood and remove the battery caps.
  5. Remove the battery caps from your RV’ battery as well.
  6. Attach the red clamp from the jumper cables to the positive pole of your RV’s battery. You must see a “+” on this pole to easily identify it as positive.
  7. Attach the other end of this red cable to the positive pole of your car’s battery.
  8. Once those two poles are properly connected, grab the black cable of the jumpers and attach one clamp to the car battery’s negative pole. Attach the other clamp of the black cable to the RV battery’s negative pole. Be careful when doing this since some sparks might fly.
  9. Let your car run for a while such that the RV battery gets charged.
  10. Follow these steps in order when removing the clamps. Remove the black clamp from the RV battery and then proceed to remove it from your car’s. Do it in that same order with the red clamps.
  11. Return the caps on your RV and car batteries.
  12. Now you got yourself a charged battery in your RV. This will get your recreational vehicle started and this will continue charging the battery until fully charged.