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Things You Need to Know About RV Batteries

RV batteries are critical components of your entire rig setup. These batteries power everything electric within your recreational vehicle, from your fridge to your HVAC system. Therefore, understanding its various aspects is of utmost importance.

In this guide, we will highlight each of the aspects to make sure you know how it works and how you can use that information.

Purpose of an RV battery

You must understand that RV batteries come with different systems. One is a 120V AC system, and the other is a 12V DC system. If you have a motorhome, you will also have the standard car battery you can use to start the engine, just like a normal vehicle.

A 120V system is far more powerful than a regular car battery because it powers the motorhome and other systems inside the camper.

For operating this battery, you must hook it with the shore power you connect it with an electricity generator. This much power can’t be generated via a solar generator, so you can’t use solar energy here. When you are all hooked up, the battery starts charging.

You can charge it with a generator, or of course, it continues to charge when you are driving. Smaller systems like fans, lights, or water can be used when your battery is not hooked. And that can continue to run until, of course, the battery is entirely out of juice.

What’s the best RV battery type?

There are different types of RV batteries available on the market. But two of the most common types of RV batteries are deep cycle RV battery and lithium RV battery.

Deep-cycle RV battery

These are lead-acid batteries, and you can find a similar one in a golf cart or a boat. It looks like a car battery and runs with similar chemistry for creating and retaining power.

These batteries can generate a very steady kind of current for a long time. On the other hand, car batteries can generate many currents in a very short time because they can charge themselves while driving.

There are different sub-categories of these batteries. These include gel-types, absorbed glass mats(AGM), and flooded wet cells. Each of these types comes with different repair and maintenance requirements.

Lithium batteries

These work as an alternative to lead-acid units. Most modern rigs come with these batteries, especially those that need to be upgraded for solar power generation. This can be a tad bit expensive compared to the lead-acid unit, but they also come with various advantages.

For instance, these batteries are lightweight and are small. You also won’t have to go through any tough maintenance requirements either.

Lithium batteries are designed in a set-it-&-forget-it fashion. These batteries come with a significantly longer lifespan for more than 5000 cycles. Most lead-acid batteries are for only around 400 cycles.

Now, that’s a significant difference. But the prices you will pay for them are almost three times more than what lead-acid batteries will cost you. So, for some campers, they are out of reach for good.

RV Battery Bank

When you join two or more batteries with each other, it forms a battery bank. It significantly improves the voltage when you need more power. As we have talked about connecting the batteries, it can be done either in series or parallel.

In series

Joining the batteries in series allows you to maintain the amperage but get more voltage. For instance, joining a couple of 6V batteries in series will give your 12 volts, and the overall amperage remains the same.

You will need a jumper wire for this, and you must connect the -ve terminal of one battery with the +ve terminal of the other battery. Another cable links the remaining two +ve and -ve points to the device that you will connect to this series. You must make sure both the batteries here have the same voltage and amperage rating.

In parallel

In this connection, amperage increases while voltage remains the same. Combining two 6V batteries parallel, you will get 6V, but you will get more amperage now.

You will have to connect two +ve terminals and two -ve terminals with each other. Now you can connect the bank with your application, and both the batteries will drain at the same rate.

In series-parallel

There is a third connection type as well, and it’s called the series-parallel bank. It will allow you to increase your amperage and voltage. You will need four batteries here, but you will have to keep track of the connections you have made.

You can join as many batteries as possible in this bank. However, it would be better for you to place them in a battery box in your recreational vehicle to keep them safe and separate. Two mini-banks joined in parallel can be connected in a series to form a mega-bank.

Battery Maintenance


Maintaining your RV batteries will be based on the type of batteries you have. As we have mentioned above, lithium batteries require significantly less maintenance as compared to deep-cycle batteries.

Other types of batteries do need to be maintained and a lot over time. Therefore, their lifespan significantly varies from one another as well. Lithium batteries are far superior in every aspect if you compare them with any other type of battery.

Most deep-cycle batteries require some essential and routine checkups that you need to carry out to ensure that they continue to perform at their best.

  • You have to maintain the electrolyte levels in the flooded cell batteries. These batteries tend to lose their water with time. And you have to replenish this water with distilled water to reduce sulfation. Sulfations involve the development of sulfate crystals when the plates are exposed to air. You have to check this battery every month and make sure the battery is fully charged before beginning the maintenance process.
  • You also have to clean those terminals and remove any corrosion build-up. Baking soda can be used here per gallon, or you can go for a commercial battery claiming product. A toothbrush can be used to scrub the areas needed.
  • Don’t let your batteries get low on charge, or you will significantly increase the chances of sulfation. When a battery falls below 12.4V or 80 percent, sulfations begin to increase. So, you need to keep them charged regularly. But don’t overcharge them, or it will damage the batteries over time.

Battery Storage

RVs are normally stored away for about some months during the winter season. Batteries do tend to discharge with time, so if you don’t take care of your battery, it will die down. Freezing can kill a flooded cell battery, but if you keep it nice and charged, it won’t go flat.

See also: How to winterize a camper?

AGMs can handle freezing way better than flooded units. But you still need to charge and take care of them properly. You need to remove the batteries from your RV and then take them with you. If you can’t take them out for some reason, you will have to take some preventive measures to keep them alive.

First of all, you have to disconnect your house batteries because fridges, radios, propane, and smoke detectors can consume small milliamps with time, and it can drain your battery flat.

Don’t assume that everything is off and the battery is not going to go anywhere. Charge them as you would normally do. If you can easily access your rig in the storage, you must charge your batteries full once a month.

Unregulated solar panels might fail to maintain their charge or end up boiling off the electrolyte. You must also not leave the converters plugged because it can result in boiling your RV batteries dry very fast.

You should also check your batteries out now and then in the store too. Charging them fully each month will be more than enough, or you will end up buying new batteries before you take out your rig.

Battery Monitors


You must determine the charge’s true status in your battery to ensure you don’t overcharge your battery. Therefore, you will need a battery monitor to be precise with the charging process.

This is a small device that can tell you what is the exact charge on your battery at the moment. It can also tell you the current state of discharge and the energy level flowing through the battery. There are different types of battery monitors available on the market. And you can install most of the aftermarket.

The modern types come with an LCD that shows essential data about your battery. Some of them can even send updates to your phone regarding your RV battery status, which is hugely convenient.

Battery Charging

Batteries behind to charge when you connect your RV with an outlet. A converter is there in every RV that converts the power from the grid into a 12V DC and then directs it towards the adapter present inside your RV.

Your RV battery will also charge when the engine is on, running, or connected to an electricity generator. When your RV is hooked up, you will know that your batteries are charging or use your battery monitor for this purpose.

You can keep your RV plugged in at all times, but it can drain the wet cell battery, and it will flat out pretty fast. Also, keep in mind that it doesn’t allow your batteries to run too low on charge because it can significantly reduce their lifespan. Charge your batteries frequently and adequately. It’s about maintaining a schedule for this.


What’s the cost of an RV battery?

The cost is going to vary a lot based on the type of RV battery under consideration. A single 12V lead-acid wet cell battery might cost you only some hundred dollars.

While a lithium battery will cost thousands, but lithium batteries also come with a long lifespan, so they remain cost-effective in the long run. Therefore, if you can afford it upfront, a lithium battery can outshine any other RV battery type.

How to install an RV battery?

You can begin by turning off all objects and applications that might draw power from your battery, including those minor lights. Keep in mind where your current battery is located. Now disconnect those cables by unlinking the -ve one first and then the positive one.

Clean these cables and then insert the battery and reattach the cables. Also, install any hold-down hardware that comes with the battery and start the engine for a test.

How many batteries are there in a motorhome or an RV?

Your RV has two different battery systems. There is a 120V AC system, and there is a 12V DC system. A self-driving RV or a motorhome also has a 12V battery for starting the engine, just like normal cars.

How long can an RV battery last?

It all depends upon how well you can maintain it. The type you also have mattered. Lithium batteries are the best because they are rated for 5000 charge cycles. Deep-cycle batteries are only rated for about 400 cycles.

Does the RV battery charge when plugged in?

Yes, when your RV is plugged into shore power, the batteries are charging. You can also charge them while driving it with the help of an electricity generator. But make sure you don’t keep your RV hooked up with shore power, or it will damage your batteries’ overall lifespan significantly, and they will begin discharging very quickly.

Final Thoughts

Indubitably, RV batteries are one of the most important components of your camper. Without it, nothing is going to work inside it. If you can take care of your batteries, that can indeed last for a long time, especially if they are lithium batteries.

Make sure to properly charge your batteries when you store your RV for colder months. Keep the batteries charged during this time but make sure you don’t overcharge them.

For this, you will need a battery monitor that will tell you how much energy is flowing through the battery and how much of it has been discharged. Essentially, it can tell you about your battery health.

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