Should I Add A Second Battery To My Camper?

Adding a second battery to your camper can really improve your camping experience. Many RV and travel trailer owners don’t understand why second batteries are helpful. When you add a second battery, your camper power changes. Depending on how you add the second battery, you either get more power or battery power that lasts longer.

In this article, we will look at the topic of dual batteries in campers. We will give you some information on how you add a second battery, the camper benefits of an additional battery, and what you need to be cautious about when altering your camper’s electrical system.

What Is an RV Battery or House Battery?

An RV or house battery is a special type of battery that is designed to power your camper lights, appliances, and other electrical features. These batteries are also called deep cycle batteries. 

Deep cycle batteries are different from engine chassis batteries that you find in your car or connected to your motorhome’s starter engine. These batteries are designed to discharge their power slowly, instead of providing a quick boost of power. Deep cycle batteries are also able to run longer before needing to charge. 

Do You Need More Than One House Battery in a Camper?

Do You Need More Than One House Battery in a Camper

You do not necessarily need to have more than one house battery in your camper or RV. All smaller travel trailers come with one house battery. For normal travel, this is usually fine. This is particularly true if you are going to be staying somewhere that you can connect to shore power.

Dual battery systems are a great option if you plan to do more off-grid camping. A benefit to adding a second battery to your camper allows features like your 12V refrigerator, water pump, and other electrical systems to run longer before you need to charge your batteries.

Do Some RVs Have Two Batteries?

Larger travel trailers and many motorhomes have two RV batteries. For example, large Class A and Class C motorhomes often come with dual battery systems. For these larger drivables, dual batteries are necessary for the numerous appliances and electrical components.

You will also find dual battery systems on travel trailers that are made for off-grid boondocking. These campers come with dual battery systems to allow you to spend a long time out in the wilderness.

Many of these off-road style campers use the dual battery system in conjunction with solar panels, which allow you to spend longer than just a few days in remote areas.

Pros Of Adding A Second Battery To A Camper

Pros Of Adding A Second Battery To A Camper

If you are considering a second battery for your travel trailer or RV, there are some great benefits to your camping experience.

1. You’ll Have More Power For A Longer Period

Depending on how you set up your dual battery system, you can either get more voltage or the normal voltage for a longer time. 

2. Ability To Run More Electric Devices

Increased voltage and/or wattage allows you to run more high-power appliances at the same time. For example, you can run the microwave and your furnace fan at the same time.

3. Run Appliances That Normally Do Not Run On Battery Power

This is one of our favorite benefits of a dual battery system set in parallel. You can actually run your air conditioner when you are off-grid. This is an amazing benefit if you are boondocking in the summer.

Cons of Adding a Second Battery to a Camper

Cons of Adding a Second Battery to a Camper

While the pros of adding a second battery to your camper make it sound pretty great, there are some cons you should consider.

1. Modifications Are Required

If you want to add a second battery to the camper’s electrical systems, you are going to have to make some modifications. The biggest modification is that you will have to add a second or larger battery box. Depending on where your battery is currently stored, this may be an easy task, or it may take a lot of work. 

You will also have to modify how your batteries are connected to the electrical system. This is not a difficult task (we will discuss more later), but you have to figure out how you want your batteries to run and connect them appropriately.

2. It Costs More

When you decide that you want to add a second battery, you cannot just add a new battery and go. For the proper operation of the system, both batteries need to be the same size and age. This means you have to buy two new batteries for your system to work correctly.

If you connect a new battery to an existing battery, the new one will only operate as well as the older one. For example, if you have an RV battery that is 2 years old, more than likely, it may only operate at 6-8V rather than 12V due to usage.

When you add a brand new second battery, that new one will operate at 6-8V because the older one cannot function any better.

3. Longer Charge Time

Since you will be charging two batteries, instead of one, the amount of time necessary for a good charge can increase significantly.

4. Storing 2 Batteries Takes More Space

If you have a smaller camper or your RV’s battery location is small, you may be challenged with fitting a second battery on your camper. Not all motorhomes or travel trailers have enough space for a second house battery. You will need to measure carefully before you start the process of adding a second battery.

How to Add a Second Battery to a Camper

How to Add a Second Battery to a Camper

It may seem like a complicated process to add a second battery to your camper. However, camper electrical systems can easily accommodate a second battery with minimal effort. 

Before you make any modifications to your camper’s electrical system, you should always read your owner’s manual. Some RV electrical systems are not equipped to handle a second battery, or can only handle a second battery when installed in a particular arrangement. 

If you are not comfortable with making the necessary modifications to your camper for a second battery, you should enlist the assistance of a professional.

The first thing that you need to do before you add a second battery is to make space for the second battery in the battery bay. This may mean adding a second battery box or other modification to accommodate the two batteries safely.

The second step in this process is to purchase two identical deep cycle batteries. We recommend that you purchase two of the same size and capacity as the original battery. If the existing battery is not properly marked, your owner’s manual should tell you the correct battery you should use.

Once you have purchased your batteries, install your batteries. You will need to decide whether to install them in series or in parallel. When you know how you want to run your batteries, you simply need to connect the batteries to the camper in the proper arrangement.

Should You Wire RV Batteries in Series or in Parallel?

Should You Wire RV Batteries in Series or in Parallel

If you are not sure if you should wire your dual battery system in series or parallel, you should think about why you are adding the dual system. Knowing your purpose for adding a second battery will make the decision about the arrangement very easy.

If you are adding a second battery because you want to have power from your batteries for a longer period of time, you should wire your batteries in parallel. This wiring setup allows you to run your electrical system at the same power level for a longer amount of time. 

If you want to increase the available voltage in your camper, you should install your batteries in series. This means that you can run your air conditioner and your microwave at the same time, without overloading the battery.

What You Should Know About a Dual Battery System

A dual battery system is a great idea, and many RV and travel trailer owners really love the convenience of having a second battery. However, as with any modification you make to your RV, there are some things you need to keep in mind.

  • Not all RV electrical systems can handle a dual battery system without significant modifications. You need to carefully read your owner’s manual before adding a second battery to your camper. Overloading the electrical system can damage key components of your RV.
  • Always use two batteries of the same size. Using a smaller and a larger battery may save you money, but the uneven distribution of power can damage one or both of your batteries.
  • Keep an eye out for corrosion at the battery terminals. Corrosion can be a good indication that a battery is at the end of its life. Corrosion can also decrease the efficiency of your batteries.

Should You Wire RV Batteries in Series or in Parallel?

Should You Wire RV Batteries in Series or in Parallel

For a long time, the only option you had for RV house batteries was lead-acid. Today, lithium-ion technology has improved, and more RV owners are switching from lead-acid to lithium. 

Just because lithium-ion is the product of the moment, doesn’t mean that it is the best option for your camper. Here are some pros and cons of both lithium-ion and lead-acid batteries.

Lithium-Ion Battery Pros

  • Lighter weight
  • 100% discharge capability
  • Longer life span
  • Consistent discharge current
  • Hold a charge even when not used for a long time

Lithium-Ion Battery Cons

  • More expensive to purchase
  • More expensive disposal
  • Requires an energy management system

Lead-Acid Battery Pros

  • Inexpensive
  • Highly reliable older technology
  • Easy to find at most automotive stores
  • Lower cost for disposal

Lead-Acid Battery Cons

  • Shorter lifespan
  • Prone to corrosion
  • Heavy
  • Discharge current decreases as charge decreases
  • Loses charge when not used for a long time (as in winter storage)

Is It Worth Having Two Batteries in Your Camper?

When you add a second battery, camper electrical systems become more efficient for some types of camping. However, a dual battery system may not be necessary or practical for every RV owner.

If your motorhome or travel trailer only has one battery, but you rarely stop somewhere without shore power, you probably do not need to add a second battery.

However, a second battery can make a huge difference if you would rather camp away from the crowds. If camping off-grid is your idea of heaven, a second battery can improve your comfort for more time away from home.

Related Reading:

1. What Size Generator Will Run Travel Trailer A/C?
2. How Often Should You Grease Travel Trailer Wheel Bearings
3. How Often Should Travel Trailer Tires Be Replaced?
4. NRVTA Home Study Course or Attend the School?
5. Should You Use Dielectric Grease On Trailer Plugs?

About the Author:

Jason Gass is a full-time freelance writer and part-time RVer whose goal is to share great stories around a campfire with good friends.

When he’s not working, he spends most of his time camping, searching for the best breweries, and road-tripping in his teardrop trailer with his wife, daughter, and two dogs.