6 Volt vs 12 Volt RV Batteries: Which is a Better for Your RV?

Are you confused about picking 6 volt vs 12 volt RV batteries for motorhomes and travel trailers? While the traditional RV battery setup calls for a 12-volt power cell, owners of more contemporary RVs use a 6-volt battery system.

Both systems deliver electricity for boondocking, camping, RVing, and other off-grid adventures. A 6V battery is more expensive than a 12V one, but it promises an extended service life and greater power output when wired in a series.

This article sheds light on the ongoing debate between a 6-volt and a 12-volt battery system for travel trailers, RVs, and motorhomes. Hopefully, it will help you decide which battery to get for your needs.

What Are the Different Battery Types for RVs?

Let us review the different battery types before discussing the difference between a 6 volt and 12 volt battery for RVs.

Starting Batteries

You can find these batteries in your engine bay, providing power to the starter and related electronics for cranking up the engine. Motors or engines require a tremendous amount of energy to start. That is why they need a battery with a high Cold Cranking Amps (CCA) rating.

In general, the larger the engine, the higher its energy requirements to start are. Moreover, high-compression engines (diesel) require more amps to start than low-compression motors.

Deep Cycle Batteries

Experts call RV house batteries 6V or 12V units deep-cycle batteries. These power units do not have sufficient stored energy to start an engine. However, their purpose is to keep electrical devices and appliances running in the absence of AC electricity.

A deep cycle battery provides constant power over long periods until about 20 percent of its charge remains. Hence, you can say the battery uses up to 80 percent of its capacity before requiring a recharge.

These batteries recharge right after the engine starts, relying on the electrical output of the car’s alternator. As long as the engine and alternator are working optimally, the battery regains its full charge.

You can use a deep cycle battery for up to a few days before the next recharge, depending on the battery’s capacity and discharge level. That is why they call it a deep cycle battery (because of its unusually long cycle from a state of complete charge to the next recharge).

However, to extend its service life, it is not advisable to discharge a deep cycle battery beyond 50 percent.

We will be referring to deep cycle batteries when talking about 6V or 12V batteries for RV.

What Are the Principal Differences Between a 6-volt and a 12-volt Battery?

There are more differentiating features between a 6V vs 12V RV battery than voltage alone. Learning these differences can help you decide which between these two battery types you should use in your RV.

Applications

In general, 12-volt battery systems are for people who do not mind the extra weight and space requirements. You get 12 volts of power compared to only 6 volts on the other product.

However, for RV owners who want to save as much space and weight as possible, the 6-volt system makes perfect sense. It is more compact and lighter than a 12-volt unit, too.

Amperage

Many 12-volt batteries on the market have an amperage rating of 50 Ah to 100 Ah. The good news is that you can connect two such batteries in parallel to increase the amperes to 100 Ah or 200 Ah.

However, doing so does not impact the voltage rating. It remains 12 volts, even though you have two 12-volt batteries.

You can connect the 12-volt batteries in a series if you want 24 volts. Unfortunately, this connection type limits the amperage rating to only 100 Ah or whatever the Ah rating of each battery is.

Connecting two 6-volt batteries in a series will meet the 12-volt power requirements of modern travel trailers, campers, motorhomes, and RVs. However, the amperage rating stays the same.

The good news is that 6-volt batteries typically have a higher amperage rating per battery than 12-volt systems. The average 6-volt battery on the market provides 225 ampere-hours, typically ranging from 160 Ah to 260 Ah.

Even if you double the 12-volt battery system, its amperage rating (100 Ah x 2 = 200 Ah) will still be lower than one 6-volt battery (225 Ah x 1 = 225 Ah).

Unfortunately, connecting two 6-volt batteries in parallel will not raise the voltage rating to 12, the RV’s voltage requirement.

Overall, it is safe to assume that 6-volt batteries have a slight advantage relative to the amperage rating. It should help you decide which RV batteries 6V vs 12V you should pick.

Cycling

Since a battery’s cycling depends on its capacity (amperage rating), we can say a 6-volt battery lasts longer than a 12-volt unit.

For example, suppose you have one 12-volt 100-Ah battery in your RV supplying power to various electric appliances when you are on the road. Let us also say you consume an average of 20 Ah per day. In that case, it will take 2.5 days before the battery reaches half its capacity.

On the other hand, two 6-volt units with a 225-Ah rating will continue operating your RV appliances for five to 6 days before charging is recommended (225 Ah ÷ 20 Ah per day = 11.25 days; 11.25 days x 50% = 5.625).

Although this is a hypothetical scenario, it drives home the point that 6-volt batteries have a longer cycle, requiring less frequent recharging.

Lifespan

Six-volt battery systems have thicker and heavier plates, allowing them to withstand chemical changes within the battery. Moreover, the battery’s extended charge-recharge cycle enables it to lose its capacity more slowly than a 12-volt unit.

On average, 12-volt batteries have a lifespan of three to six years. On the other hand, a 6-volt battery can last up to eight years under ideal operating conditions.

Weight and Size

While 6-volt batteries are lighter than 12-volt systems, the difference is not that significant. On average, a 12-volt battery can weigh between 65 and 80 pounds, depending on the model and type. On the other hand, a 6-volt unit can weigh anywhere between 55 and 70 pounds.

A 6-volt battery’s principal advantage is its compact size. Twelve-volt units are bulky, often requiring two people to carry one battery.

What Are the Pros and Cons of a 6-volt and a 12-volt Battery?

Here is a rundown of the advantages and disadvantages of 6V and 12V batteries.

12V Pros

12V Cons

6V Pros

6V Cons

What Is a 12-volt Battery System for RVs?

Almost all vehicles run on a 12-volt battery system, whether the latter works as an engine starter or a deep cycle power storage unit. You can pop the hood of your car, check the battery, and it will have a 12-volt system.

A 12-volt battery system is inexpensive and readily available in almost every automotive supply shop and battery store.

Trucks and other large vehicles often connect two 12-volt batteries to increase the power output to 24 volts. A 12-volt battery typically has 35 to 70 ampere-hours (Ah), although it is not uncommon to find products with a lower or higher ampere rating.

What Is a 6-volt Battery System for RVs?

Mostly found in golf carts, 6 volt RV batteries are also applicable for electric vehicles (e-scooters, e-bikes, e-wheelchair, etc.), UPS systems, and lighting systems for roadworks and other construction projects.

It is also suitable for boondocking and camping because of the 6-volt battery’s higher amperage rating.

Conclusion

Deciding between 6 volt vs 12 volt RV batteries is a breeze if you know what you want. Most RV owners will pick a 12-volt battery because of its affordability and availability. You will likely never worry about connecting more than one 12V battery to your system to run your motorhome’s electric devices.

On the other hand, a 6-volt battery is suitable for RV owners who have no issues with price and access to this power unit type. It is also ideal for people with small vehicles.