Before you hit the road, ensuring your RV batteries are in good working order is best. Otherwise, you risk waiting for a tow truck to get you jump-started. RV batteries must reliably perform several jobs to power an energy-hungry home away from home.
They have to start the engine and run lights, water pumps, heat, appliances, and more. Given this tall order, installing the right batteries for your RV and maintaining them properly is imperative to problem-free excursions.
Understanding Basic Battery Terminology
RV, truck, and boat batteries are typically broken into two main uses: starting batteries and house batteries.
Starting Batteries
The battery used to start and run the engine is referred to as a starting battery. Starting batteries deliver high bursts of power over short periods of time. These batteries are rated in Cold Cranking Amps (CCA). The power level you need depends on the cranking requirements of your engine.
CCA is the number of amps the battery can deliver at 0 degrees Fahrenheit for 30 seconds without dropping below 7.2 volts.
Starting batteries are also rated by Reserve Capacity (RC). RC represents how long the battery will operate essential equipment if an alternator or generator fails.
RC is the duration, in minutes, that a battery will deliver 25 amps at 80 degrees Fahrenheit.
House Batteries
The batteries used to supply power to the RV itself are commonly referred to as house batteries. These deep-cycle batteries provide a steady amount of current over longer periods of time.
Deep-cycle batteries are designed to be deeply discharged and recharged repeatedly and are rated in Amp Hours (Ah) and Reserve Capacity (RC).
The Ah rating is the number of amperes (amps) that a battery can deliver for a 20-hour period.
This test also is referred to as the 20-hour rate. The larger the Ah rating, the more power the battery can deliver over time.
What is Depth of Discharge (DoD)?
Depth of discharge is the percentage of a battery’s capacity that has been used relative to its overall capacity.
Conversely, a battery’s state of charge is the percentage of remaining battery capacity. The more often a battery is charged and discharged, the shorter its lifespan.
With most battery types, fully discharging its capacity isn’t recommended. This vastly decreases the battery’s life, so follow the battery manufacturer’s recommended maximum DoD if you want to optimize your battery’s performance.
Understanding Battery Types
There are three main types of RV batteries: flooded, absorbent glass mat (AGM), and lithium.
Flooded RV Batteries
Flooded batteries are still considered the standard for RV and boat use. As RVs require, they are designed to run multiple appliances at once. The downside of flooded batteries is that they require the most maintenance, even in the offseason.
The Interstate Marine/RV and Interstate GC2 batteries below are examples of flooded RV batteries.
AGM RV Batteries
AGM batteries are considered the next step up from standard flooded RV batteries. Depending on the model, they offer as much as twice the overall power and three times the lifespan of conventional marine batteries.
They also boast a higher DoD (up to 80%) and require less maintenance in the offseason. The Odyssey battery below is an example of an AGM battery.
Lithium RV Batteries
Lithium batteries are currently the top-tier RV batteries on the market. They offer a long cycle life (up to 2,000 cycles) and a higher DoD (up to 100%) than flooded and AGM batteries. Lithium batteries also require the least offseason maintenance of these three battery types. The Expion360 battery below is an example of a lithium RV battery.
Lithium batteries do, however, require charge systems designed for their unique chemistry. You may not be able to swap directly from a flooded or AGM battery to a lithium battery without installing a battery management system or verifying your RV’s current charge system can support an RV lithium battery upgrade.
How Long Do RV Batteries Last?
A battery’s life cycle is the number of charge/discharge cycles it can sustain in its useful life. It will vary dramatically depending on how much of the battery’s capacity you normally utilize.
An RV battery can last anywhere from one year to several years, depending on how it’s used, maintained, discharged, recharged, and stored. Generally, flooded batteries need to be replaced most frequently, and lithium batteries offer the longest lifespan.
Deep-cycle batteries come in a variety of sizes and have varying Ah ratings. Some are designated by group size (24, 27, and 31). Depending on your needs and the space available in your RV, there are several battery selection options, including:
- One 12-volt group 24 deep-cycle battery that provides 70 – 85 Ah.
- Two 12-volt group 24 batteries wired in parallel to provide 140 – 170 Ah.
- Two 6-volt batteries wired in series to provide about 100 Ah, or four 6-volt batteries can be wired in series/parallel to provide about 200 Ah.
How Long Will an RV Battery Last While Boondocking?
If your RV spends most of its time plugged into an electrical source, battery maintenance will be your main concern, as opposed to worrying about getting the highest Ah. On the other hand, if you like boondocking and consider RV hookups optional, you’ll want a deep-cycle battery with the highest Ah capacity you can fit in your RV.
Of course, there are ways to keep your batteries charged so you can stay out longer. Running your RV generator is the simplest way, but you can also explore adding solar panels to your RV if you’re interested in extended boondocking.
How To Charge RV Batteries
The electrical system in your RV is designed to recharge the house batteries in the following ways:
- When plugged into shore power (by way of the converter)
- When connecting a towable RV to a tow vehicle (by way of the trailer wiring)
- When running the engine of your motorized RV (by way of the alternator)
- When using a solar battery charger for RV use
So, the good news is that there are several ways in which your batteries will charge naturally. The methods you’re able to use will depend on what type of RV you have and what solar packages came from the manufacturer or were installed by you or a former owner.
But what if you follow the recommendations set forth by many manufacturers and remove your battery (or batteries) when your RV is in storage?
In this case, you’ll need to use an RV battery charger to keep your batteries from discharging past their recommended level (consult your battery’s manufacturer to learn what that level is). If you remove your batteries for storage, they should be kept in a cool, dry place and charged monthly to keep them from discharging to an unhealthy level.
What is the Best RV Battery?
To aid your decision, here are some of our top-selling batteries you can find online or in Camping World retail stores nationwide:
Interstate Marine/RV Deep Cycle 12-Volt RV Battery
- 550 CCA
- 140-minute RC at 25 Amps
- 81 Ah rating
- Group Size: 24M
- Technology: Flooded
- Dimensions: 11″ L x 6.875″ W x 9″ H
- Battery Weight: 46.3 pounds
Interstate GC2 Deep Cycle Extreme 6-Volt RV Battery
- 447-minute RC at 75 Amps
- 225 Ah rating
- Technology: Flooded
- Dimensions: 10.3125″ L x 7.125″ W x 11″ H
- Battery Weight: 62 pounds
Odyssey 12-Volt Marine Dual-Purpose Performance Battery
- 725 CCA
- 155-minute RC at 25 Amps
- 63 Ah rating
- Group Size: 24M
- Technology: AGM
- Dimensions: 10.9″ L x 6.8″ W x 8.8″ H
- Battery Weight: 51.4 pounds
Expion360 VPR 4Ever Classic 12.8-volt Lithium RV Battery
- 1280 Watt-Hours
- 100 Ah rating
- Group Size: 27
- Technology: Lithium Iron Phosphate (LiFePO4)
- Dimensions: 11.93″ L x 6.81″ W x 8.59″ H
- Battery Weight: 31.1 pounds
Where To Find RV Battery Boxes
An RV’s battery box protects the battery inside from the elements. These boxes can sometimes crack and need to be replaced, but you may also need to upgrade if you’re not going with a direct RV battery replacement.
Most battery boxes for RV use are designed for one or two batteries. Their sizes also vary based on the group size or dimensions of the battery they’re intended to hold. Here are a few of our top choices:
Camco Standard 24M RV Battery Box
- Lightweight, heavy-duty, corrosion-resistant polypropylene box
- Lift-off lid
- Durable woven hold-down strap and foot clamps
- Fits group size 24 batteries
- Meets USCG and ABYC specifications
- Inside Dimensions: 7.25″ W x 10.75″ L x 8″ H (2″ additional room for battery terminals)
Camco Dual Battery Box For RV Use
- Holds two 6V Group GC2 batteries or two 12V Group 24/24M batteries
- Made of durable, heavy-duty, corrosion-resistant polypropylene
- Includes two straps and four clamps with screws
- Meets USCG specifications
- Inside Dimensions: 21.5″ L x 7.4″ W x 11.2″ H
Camco 6V Marine and RV Battery Box
- Safely stores and protects your 6V battery from collisions and contaminants
- Made of heavy-duty, corrosion-resistant polymer
- Includes strap and two strap clamps with screws
- Meets USCG and ABYC specifications
- Inside Dimensions: 11″ L x 7-3/8″ W x 11-3/16″ H
Explore our full selection of RV battery boxes to find the right one for your RV.
RV Battery Maintenance Tips
Most batteries require some maintenance – even those advertised as “maintenance-free”. A few simple steps will keep yours clean and free of corrosion:
- Consult your owner’s manual. Different battery types require different maintenance. So the best place to start is to see what your battery manufacturer recommends.
- Keep it charged. Letting your battery discharge past 12 volts leads to sulfation and shortens its life. Use a voltmeter to measure battery voltage and keep it fully charged.
- Clean terminals regularly. You can also coat them with a battery terminal spray.
- Check electrolyte levels monthly. Relevant to flooded and non-sealed AGM batteries. Check and fill with distilled water as needed.
- Remove for long-term storage. When winterizing your RV, remove the batteries, recharge them fully, and store them in a cool place. If you don’t remove your battery, ensure the battery disconnect switch is changed to the ‘Off’ position to prevent parasitic draws.
RV Battery Safety Tips
Staying safe when replacing or upgrading your RV batteries is vital. Here are a few important safety tips.
- Parallel connections (+) to (+) and (-) to (-) increase the Ah rating by the number of batteries used in the circuit, but not the voltage.
- Serial connections (+) to (-) and (-) to (+) increase the voltage, but the Ah rating is the same as a single battery.
- When making either a parallel or serial circuit, all batteries must be of the same rating, age, and design type.
- It is extremely important not to mix battery types (Flooded, Gel, AGM).
Batteries are available at Camping World SuperCenters nationwide. Go here for a listing of Camping World stores.
Regardless of your battery choice, consider Good Sam Roadside Assistance plans so a tow truck is a phone call away when you run into issues on the road.
Do you have any questions about RV batteries? Leave a comment below!
We often hear of lithium batteries in electric vehicles catching fire. Is this also a concern with lithium batteries in an RV?
Hi Dana,
Lithium batteries come in many different chemistries, and each has very different characteristics. The very popular Lithium Ion style is in phones, power tools, and many other devices because of it’s affordability. These will burn or explode if physically damaged. The batteries used in RVs are usually Lithium Iron Phosphate, or “LiFePo” and can withstand serious abuse or damage while remaining safe and stable. These batteries are typically very expensive.
Hope that helps!
I have a 23’ travel trailer. I want to install 2 batteries that I can use solar panels to charge when I’m dry camping. What do you recommend?
I am looking for two deep cycle batteries to replace my house batteries in my motor home.
I need the battery to be 12.5″ long by 6.75 wide. Do you have any in stock at the Fife WA store?
Hi Pat! Lithium is where many folks are going these days, but I would start with some of our content on solar for RV camping.
https://blogcw.local/rv-basics/inside-your-rv/using-solar-power-rv/
https://blogcw.local/at-the-campsite/boondocking/how-to-get-the-most-out-of-your-solar-panels-this-summer/
As for the best setup, it will really depend on your trailer. So I’d suggest contacting a Camping World Performance Center to speak with a specialist that can provide personalized suggestions for what’s best for your trailer and your RV lifestyle: https://rv.campingworld.com/rv-performance-improvements
Hope this helps!