RV Battery Options: 12-Volt or 6-Volt?
If you’ve chatted with serious boondockers or dry campers, you’ve likely heard lots of opinions about RV batteries. Some campers love their 12-volt batteries, while others insist 6-volt batteries are the way to go.
With all these different viewpoints, it can be confusing to know what’s really best. Let me break down the facts so you can make your own choice.
For my boondocking adventures, I prefer 12-volt lithium batteries connected to solar panels. However, lithium might not be right for everyone, especially weekend campers or folks who mainly stay at campgrounds with electrical hookups.
So what’s the ideal setup when choosing between lead-acid 12-volt and 6-volt batteries? The answer really comes down to how you camp. Let’s look at both options and figure out which one matches your RVing style best.
12-Volt vs 6-Volt
12V RV Batteries
Flooded lead-acid 12-volt batteries are the go-to choice for most RVs, trailers, and campers. They deliver the power your RV needs without having to connect two batteries like with 6-volt options.
Most RVers pick deep cycle marine batteries because they’re cheap and sold almost everywhere. You only need one 12-volt battery to power your RV, and if you have two and one stops working, the other keeps things running.
They’re also easy to connect if you want more power. The downside? High-capacity 12-volt batteries can be very heavy, a 200Ah battery might weigh over 100 pounds and may not fit in smaller compartments.
While they might not last as long as some 6-volt batteries, 12-volt batteries offer good value, wide availability, and simplicity for most campers.
My Verdict
For weekend campers and those who mostly stay at hookup sites, 12-volt flooded lead-acid batteries are the practical choice thanks to their lower cost, wide availability, and the ability to run your RV with just one battery.
Pros
- You only need one battery to run your RV.
- If you have two and one stops working, the other can still power your RV.
- Cheaper than 6-volt batteries.
- Easier to find when shopping.
- Simple to wire multiple batteries for more power.
Cons
- Larger high-capacity batteries can be very heavy.
- Flooded lead-acid might not last as long as 6-volt batteries.
- Might not fit in small RV battery compartments
6V/Golf Cart Batteries
6-volt batteries are built tough. They work like 12-volt batteries for powering your RV off-grid, but with a twist, you need two connected in series to reach the 12 volts your RV requires.
Many campers prefer them over deep cycle flooded-lead acid batteries because they have thicker plates that handle deep discharges better and last longer. The downside? If one battery fails, your whole system might stop working.
They cost more and aren’t as common in stores as 12-volt options, but for extended boondocking trips, their durability makes them worth considering.
My Verdict
While more expensive and requiring at least two batteries wired in series, 6-volt batteries are ideal for serious boondockers who want flooded lead-acid batteries with more durability, easier handling, and better space efficiency in their battery compartments.
Pros
- Often tougher than 12-volt marine deep cycle batteries.
- Easier to handle than big, heavy 12-volt batteries.
- Take up less space.
Cons
- If one battery fails, your RV won’t have power
- Harder to find in stores
- Usually more expensive
Parallel vs Series Wiring
When you wire batteries in series, you increase voltage but not amp hours. This makes more sense if you think about watt-hours (voltage × amp hours):
- One 12-volt battery with 100Ah = 1,200 watt-hours
- Two 12-volt batteries (wired in parallel) with 100Ah each = 2,400 watt-hours
- One 6-volt battery with 225Ah = 1,350 watt-hours
- Two 6-volt batteries (wired in series) with 225Ah each = 2,700 watt-hours
6-Volt vs 12-Volt Batteries: What’s Really Different?
Why do some RVers prefer 6V batteries over 12V ones?
Many campers believe 6V (golf cart) batteries last longer because they’re built with thicker internal plates and designed to handle more charging cycles than 12V batteries.
This is partly true, for some 12V deep cycle batteries, but not all of them. If you invest in a quality 12V deep cycle battery that isn’t designed for marine engines (like AGM, Gel, or Lithium), it can be just as durable as a 6V battery.
Weight is another big difference. Two 71-pound 6V batteries with 225Ah are much easier to handle than one massive 114-pound 12V battery with 200Ah.
6V batteries are also smaller and more likely to fit in your RV’s battery compartment compared to an extra-large 200Ah 12V battery.
That said, you can always buy two regular 100Ah 12V batteries and connect them to get the same 200Ah capacity for your RV.
Choosing the Best RV Battery Setup
When picking the right battery setup for your RV adventures, here are the key things to think about:
Camping Style
Where do you usually camp? If you mostly stay at places with electrical hookups, a basic setup with one 12-volt battery or two connected together might be enough. But if you camp off-grid for days at a time, you’ll need more battery power. Boondockers should look for setups designed for heavy use.
Battery Capacity (Amp Hours)
Battery capacity shows how much energy your batteries can store, measured in amp hours (Ah). For weekend trips or if you don’t use much power, one or two 12-volt batteries might work fine. If you run lots of appliances or need power for many days, look for higher amp hours. More capacity means your lights, fridge, and devices run longer between charges.
Weight and Handling
Big batteries can be heavy! If weight matters to you or if you sometimes need to move your batteries, consider using two smaller 6-volt batteries instead of one large 12-volt. Smaller batteries are easier to lift and might fit better in tight spaces.
Space in Your RV
Check your RV’s battery compartment size. Some setups (especially with multiple 6-volt batteries) need more room for both the batteries and the wiring. Make sure what you choose will actually fit in your RV.
Durability
How long will your batteries last? 6-volt batteries often have thicker plates inside that help them handle deep discharges better. But good-quality 12-volt batteries (like AGM, Gel, or Lithium) can also be very durable. Think about how often you’ll use your batteries when deciding.
Emergency Backup
It’s smart to plan for problems. With 12-volt batteries, if one fails, the others can often keep things running. With 6-volt batteries wired in series, if one dies, your whole system might stop working. This is worth thinking about for safety.
Cost
Money matters! Six-volt batteries are usually built tougher, but they cost more than standard 12-volt batteries. Besides the price of the batteries, think about installation and any extra equipment you might need. Sometimes spending more now saves money later if the batteries last longer.
Future Expansion
Think about your future needs. If you might want to add more batteries later, a 12-volt system lets you add one battery at a time. With 6-volt batteries, you usually need to add them in pairs, which is a bit more complicated.
By keeping these factors in mind, you can choose a battery setup that gives you enough power, fits in your RV, stays within your budget, and keeps everything running reliably wherever you travel.
My Choice For The Best RV Battery Set-Up
After looking at the options, I think a 12-volt battery setup is the best choice for most RVers for these reasons:
- Ease of Use and Simplicity – A 12-volt system is easy to set up and doesn’t need the complex wiring that 6-volt batteries require. This makes it simpler for beginners or those who aren’t electrical experts.
- Flexibility in Emergencies – With 12-volt batteries, if one fails, your other batteries can still power your RV. With 6-volt batteries, if one dies, your whole system will stop working.
- Wide Availability – You can find 12-volt batteries almost everywhere. If you’re traveling and need a replacement fast, most hardware stores and auto shops carry them.
- Affordability – Good 12-volt deep cycle batteries usually cost less than 6-volt options, saving you money, especially if you don’t need tons of battery capacity.
- Fits Standard RV Storage Areas – RVs are designed for 12-volt batteries, so they fit perfectly in standard battery compartments. While each 6-volt battery might be smaller, the whole setup often needs more space.
- Easy to Handle – Regular 12-volt batteries aren’t too heavy to move. Two 100Ah 12-volt batteries are easier to manage than one huge 200Ah battery or multiple 6-volt batteries.
- Durable Advanced Options – If you choose AGM, Gel, or Lithium 12-volt batteries, they can last just as long as 6-volt options. This makes 12-volt setups great for long-term use.
- Works for All RVers – Whether you camp on weekends, live in your RV full-time, or sometimes go off-grid, a 12-volt battery setup can meet your needs without making things too complicated.
While 6-volt batteries have some advantages in certain situations, the simplicity, lower cost, and flexibility of 12-volt batteries make them the better choice for most RVers. No matter how you like to camp, a 12-volt RV battery setup can give you reliable power without extra headaches.
Frequently Asked Questions
Why do some RVers choose flooded lead acid RV batteries?
Many RVers pick flooded lead acid batteries because they’re much cheaper to buy than AGM or Lithium options. These traditional batteries have been around for decades, so they’re available almost everywhere and most RVers understand how to use them.
Even though you need to check water levels and clean terminals regularly, the low price tag makes them attractive for campers on a budget. For those who don’t mind a bit of maintenance, these tried-and-true batteries offer a familiar and affordable power solution that gets the job done.
Can I mix 6-volt and 12-volt batteries in my RV?
No, you can’t mix 6-volt and 12-volt batteries in the same system. These different types have different voltage and amp hour ratings, which would create imbalances that hurt performance and can damage your batteries.
Always stick with one type, either all 12-volt or all 6-volt batteries, to keep your system working properly.
How long do RV batteries typically last?
How long your RV batteries last depends on the type and how well you take care of them. Regular flooded lead-acid batteries usually last 3-5 years, while AGM and Gel batteries often last 4-7 years.
Lithium batteries are the champions, often lasting over 10 years. Taking good care of your batteries, like not letting them drain too low and keeping them charged, can make them last much longer.
Can I run my RV on just one 6-volt battery?
No, your RV needs 12 volts of power to run, so one 6-volt battery won’t work by itself. You’ll need to connect two 6-volt batteries in series to get the 12 volts your RV needs. If you only have room for one battery, you’ll need to go with a 12-volt option.
What’s the best type of RV battery for boondocking?
For camping without hookups, lithium batteries are the best choice because they hold lots of power, weigh less than other types, and can handle being drained low without getting damaged. The downside? They’re often more expensive and most RVs don’t have the ability to charge them properly.
If lithium isn’t in your budget, high-quality AGM or Gel batteries make great alternatives for off-grid camping.
How do I know if my RV batteries are fully charged?
Most RV charging systems have lights or displays that show the charge level. You can also check with a simple multimeter.
For regular 12-volt batteries, a full charge shows about 12.6-12.8 volts when not being used. For 6-volt batteries, each one should read around 6.3-6.4 volts when fully charged.
Can I overcharge my RV batteries?
Yes, overcharging can harm your batteries, especially lead-acid types. Use a smart charger or an RV converter with a built-in controller to prevent overcharging.
Lithium batteries usually have protection systems built in, but using the wrong charger typically results in an undercharged battery rather than an overcharged one.
Is it better to store my RV batteries inside during the winter?
Yes, keeping your batteries in a temperature-controlled place during winter is best. Cold weather can reduce how much power they hold, and flooded lead-acid batteries might freeze if they’re not fully charged.
Disconnect the batteries, clean them, and store them in a dry, cool spot to help them last longer.
How do I safely dispose of old RV batteries?
Never throw RV batteries in the regular trash! Take them to a recycling center or a store that accepts used batteries, like auto parts shops. Many places will recycle the materials properly, which prevents environmental damage and follows disposal laws.
Do I need a special charger for AGM, Gel, or Lithium batteries?
Yes, different battery types need different charging methods. AGM and Gel batteries require chargers designed for their lower charging voltages. Lithium batteries need chargers made specifically for their unique charging patterns.
Using the wrong charger can damage your battery or make it wear out faster.
How many batteries do I need for my RV?
The number of batteries you need depends on how much power you use and how you camp. For basic weekend trips, one or two 12-volt batteries should work fine.
If you often camp without hookups, figure out how much power you use daily and choose enough batteries to meet your needs. Adding solar panels or a generator can help reduce how many batteries you need.
Nice article. For those of us still trying to make the decision, I’ve read another article similar to yours That says 6v is the way to go, no question. Ha! Paralysis by analysis.
I agree, the decision between the two can be really difficult because of all the opinions. I think even just a few years ago 6V batteries were technically better but now 12V batteries have gotten much better, especially AGM ones.
For my trailer, I use 12V batteries because most of the time I’m camping hours away from any stores. If I used 6V batteries and one of them stopped working I wouldn’t be able to use any of the electrical in my trailer. With 2 12V batteries, I know that I could still use the electrical if one of them went out. That reason alone was enough for me to choose 12V.
That’s just my reasoning though, I think it’s different for everyone and in the end, both are good options.
while I agree that technology has gotten better, I don’t believe durability has…. we live in a throw away society and if you are truly living or believe you may be living off grid technology isn’t always the answer longevity speaking.
Spot on!!! I am simply overwhelmed with information and opinions. I don’t know what to do!!! #HeadSpinning
Thanks Jenni. One question – you mentioned several times you would choose “good quality” 12v batteries over 6v… do you have advice on what you brands and types you would consider “good quality”? A lot of us would revert to Costco/Interstate batteries, but I’m thinking those are not really what you are talking about. I think you implied they’d be AGM? Thanks again!
Hi Jim,
Yeah, the batteries from Costco are most likely RV marine batteries, so they are not going to be as durable as 6V batteries. But if you choose a 12V AGM or lithium battery that are true deep cycle batteries, they will not only be able to discharge lower but also last longer.
You can find my reviews and suggestions for the best AGM RV batteries here (click to view). If you are curious about lithium RV batteries you can read about those in my article here (click to view). If you go with Lithium batteries make sure the built-in RV charger is capable of charging them. You can read more about that in the Lithium battery article as well.
Hope these articles are helpful, good luck with the batteries.
When you say you have two 100 amp/hr batteries, you really have only 100 usable amp/hrs because of the discharge limit on lead acid batteries. Is this a correct statement?
Thanks
Hello Chuck,
Yes, it’s a correct statement based on the general rule of thumb to keep lead acid batteries above 50% for longevity reasons.
Thanks Jesse. Costco has a 12volt golf cart battery that has “amp/hrs: @20 hours:150. This is on the battery. How many usable amp hours would I he able to use?
Does this mean 150 amps continuous for 20 hours? I’m thinking about using it on my camper without an inverter.
Thanks
Chuck
I believe the @20 hour AH rating is what the battery can deliver in total in 20 hours (@7.5A per hour), so it’s a 150Ah battery.
With the general rule of thumb being to keep these kinds of batteries above 50%, that would give you 75 usable Ah. That’s a great big battery.
Jesse
Yes the 50% rule is for planning purposes based upon your estimated need. However a quality lead acid deep cycle like the Trojan RE can be discharges as deeply as 80% and still give a 1,000 cycle life if cycled this deeply all the time. If only cycled 50% it’s rated cycle life is about 1,600 cycles. Here’s a spec sheet illustrating my point. https://www.trojanbattery.com/pdf/datasheets/T105RE_TrojanRE_Data_Sheets.pdf
As you can see from the chart, discharge rate also material affects battery capacity. This T105-RE will provide up to 200 usable amp/hrs if only discharged at the 100 hr rate and as few as 117 amp/hrs discharged at the 2 hr rate.
A superior battery chemistry is LiFePo-4 which can be discharged even more deeply, at a much higher rate and still deliver it’s rated amp/hr capacity. Of course they have their unique drawbacks, such as not charging them below freezing, and their high price, but their rated life is much longer making most a very good value over time. The best value today, if you are a do it yourselfer is the prismatic cells, particularly the 280ah cells. One can build a battery with over 500 usable amp hrs (and 4000 cycles) including the BMS, for less than the price of a single 100ah Battleborn.
One fact regarding 12V in parallel that was missed is the circulating current if the batteries do not have identical internal impedance or static voltage. For example, battery 1 has 0.25 voltage difference over battery 2. This would cause circulating current flow between the two batteries with the higher voltage battery working to bring up the voltage of the lower battery. Since internal impedance is slightly different that circulating current is constant, eventually running both batteries down to nothing.
Now for RVs that are being charged on a daily basis the detrimental effect is negligible, but RVs in storage would be affected therefore an interconnecting cable should be disconnected. Same effect happens with diesel trucks having two batteries if the truck is stored for several months without use. A caveat to the above described effect is that when batteries are replaced it helps to replace all with identical.
I agree, especially with the newer r.v.’s. There is a lot of parasitic discharge. Although minute singularly, added together they add up. I have an older battery I put in for over winter, and store my agm’s in the garage. The progressive dynamics 45 amp charger keeps it topped all winter with no issues. Over time, before I did this without it plugged in, after about a month or 2, I was getting a low battery alarm. I have never tried to find the length of time I save on battery life.
well stated……
Is the 20 actually what the battery is rated to provide at 20°c ?
Temperature will affect a battery greatly because it is a chemical reaction.
Thanks for the question, after doing some more reading I found that the RC (rated capacity) and AH (amp hour) capacity are both tested over 20 hours at 80°F (26.6°C). The 20 must mean the 20 hour rate the batteries are tested and rated for.
In all my years of internet research I have never come across so much controversy about a given subject. All I want to do is to increase the usable battery time when I’m at the deer lease or at the beach without hookups. I use two 12 volt batteries in my boat for the trolling motor and they seem to last all day no matter how much I troll around so it seems to me two batteries is better than four. I don’t need an extra 150 lbs. in the front of my RV and I don’t really have the space to give away. I believe the amp hours differences discussed here at minute differences and shouldn’t be the only factor when it comes to making a decision. I want to thank Jenni for her insight and clarification regarding different types of batteries and helping me to decide which way to go.
Thanks for the comment Abel. I’m glad the post was helpful to you.
In your comparison of batteries you use watts, eg 12v x 100ah=1200W, but some batteries have 2 ratings. As an example an amp hour rating of 90 and also a reserve rating of 175. So which do you use to calculate the watts? It is a group 27 12V deep cycle lead acid battery. Different manufacturers seem to use different rating systems, how do you compare apples to oranges?
Hi Bob,
The amp hour rating and reserve capacity rating are two separate things. Usually, when trying to figure out the total number of watt hours a battery has it’s better to go by the amp hour rating number than the reserve capacity one.
But not all batteries have the amp hour rating, some will only tell you the reserve capacity. If you only see the reserve capacity the best way to estimate the amp hours is to divide that number by 2. It’s not going to be 100% correct but it will give you an idea as to how many amp hours the battery has so you can calculate the watts.
👍 article thanks . Will solar panels charge batteries that are totally dead ? Read a few and general answer is no . Batteries need to be +50% (?)
we’re dry camping and have two 6v and not working out great so far . Fixed a problem that I think made the batteries die so we need to get them up again .
Really simple needs – water pump for sinks, toilet and very quick shower and enough to keep gas fridge on .
A solar panel may actually be able to what a battery charger won’t. The newer high tech chargers need to recognize voltage to start charging. A solar panel, like the old school chargers or jumping from another battery, simply routes 12v into the battery. And the battery doesn’t care if the electrons come from the sun or the wall outlet.
Hi Jenni. I have a question for you. I understand that the old 6 V batteries used to be better than the old 12 V batteries. But if you have two interstate 6 V battery 210 amp hours in series for 12 v at 210 AH “GC6 Costco” compare it to two interstate 150 AH 12 V batteries in parallel for 12 v at 300AH. “GC12 Costco” Using the 50%rule you would be comparing 105 ah for the 6s to 150 ah for the 12s. All The batteries are interstate golf cart batteries. Would it not be hard to assume that 150ah with the 2-12s would be better? It is 50% more power than the 105ah of the 6vs. Thanks Gordon.
Hi Gordon,
Thanks for the comment, and I agree the 12v set up is better in most cases. The only downside to consider with the 12 volts is how large the batteries are going to be. Some RVs have limited space and if you can’t fit large 150 ah 12 volt batteries the 6 volts could possibly work better.
I personally use the 12 volt set up for the reasons you outline. If you’re deciding between the two kinds and you have the space for the 12 volts I would go with that set up.
In my case I found that two 6V batteries was a far better option. Two “True Deep Cycle” batteries gave me 235AH @ 20 hour rate. Two 100AH 12V batteries would not only be less total capacity but would also cost me more. Two 6V 235AH batteries set me back $133 each so a total of $266. I couldn’t find a 100AH battery for less than $175 each or $350. Size was the other reason. My RV was designed to house two group 24 12V batteries. The GC2 6V golf cart batteries were almost the same width, shorter in length and only an 1-1/4″ taller. They fit my compartment perfectly. There is no way my compartment could house two 100AH 12V batteries. I couldn’t even fit 2 group 27 batteries let alone a group 31 size battery.
AGM v/s flooded is the other debate. AGM is less maintenance but are a little more finicky about charge rate. They also cost a lot more for less capacity over flooded batteries.
In my case I went with a pair of very good quality Duracell 6V 235AH flooded batteries made by East Penn MFG. Same battery as the Deka. They can be picked up at any Battery Plus store. Any golf cart shop would carry something similar as well. Never “lost” a battery suddenly so not really worried about that. Added a battery watering system so maintenance is a piece of cake.
I agree that there are situations where 12V batteries make more sense. If my batteries were housed inside the living compartment, or in a larger compartment that could hold group 31 batteries, I may have gone the 12V route. If I was made of money and had a new motorhome I may go with LiFEPO4 for the reduced weight, deeper discharge and quicker recharge capability. My MH is a 1992 model Airstream and I’m not going to invest thousands of dollars into batteries.;)
Hey Julius,
Thanks for the insights. Your reasoning sounds perfect for your set up and I agree that if you have limited space, budget, and charging limitations 6 volt flooded lead acid batteries are a great option.
I did the same as you Julius for the same reasons and I’m very happy with my set up as well.
A 6 volt battery for RV is actually a golf cart battery because they have thicker plates inside than a 12 volt deep cycle battery. With a thicker battery plate, the 6 volt battery is able to deliver more long term energy and sustain deep discharging and recharging.
Cycle Life: 850
Amp Hours: 220 AH at 20 Hour Rate
Rate of Discharge: 492 min @ 25 Amps
Do these answers apply to engine batteries? Why 4/ 6volt in my diesel powered puller as opposed to 2/ 12 volt for the engine ? The 6 volts are connected in series and parallel which further confuses me.
Your system is still 12 volt. The only thing engine batteries do is crank the starter. Once the engine is running the alternator takes over. Two 12v batteries are connected in parallel- (+ to +) and (- to -). Same voltage, twice the amperage. If you have four 6v batteries, that’s 24 volts total, so you need to make them into two 12v batteries. So each pair is wired in series (- to ground, + to – of next battery, + of that battery to load) and then the 2 series are wired in parallel. So both – go to ground, both + go to load (the starter, etc).
I grew up in farming and logging country and back then anyone who had a diesel ran two 6 volts. I never knew why but they all seemed to feel it made a stronger system.
I went with Marine 12 volt primarily for cost. Group 29DC at walmart can be purchased for $100 each with 3 year warranty and the stores are everywhere should you have a failure. True that marine batteries aren’t 100% true deep cycle as they do have a cranking amp rating listed but I think this is a good thing in my case. My motorhome has separate house and chassis batteries and should I find my chassis batteries dead I can hit a boost button that cross feeds the two systems and allows it to become one for emergency starting of the engine or generator, so I dont mind the trade off.
Hi Jenni, I have a question regarding 6v battery installation in my RV. When doing 6s in series does it have to be in sets of two? My space is limited and I am wondering if I can put 3-6v batteries in series?
Hi Randy,
When it comes to 6 volt batteries being wired to create a 12 volt system you have to series wire them in pairs to get a 12 volt output that’s compatible with an RVs electrical system.
If you wire 3 6 volt batteries in series you end up with an 18 volt output.
If you have limited space you could get two high capacity 12 volt batteries instead like some of the ones in this review (click to view).
I’ve actually had other campers ask about this before, thanks for bringing it up in the comments, good luck with your RV battery installation.
Find a knowledgeable DEKA battery dealer ask for a true 12 v deep cycle battery GP 27 24 31 depending on your space and ah needs. I have been using East Penn products for years both in my personal stuff and in industrial battery backup systems. The dealer should be able to get you a 12v that will perform as well as the 6v system and be very cost effective and reliable. Weight will be more not only because of 12v but because East Penn plates seem to have more lead in them. Better than most in my opinion based on 30+ years experience.
Awesome advice Edward, thanks for the comment!
I have a different situation going on. Have a cabin near Mt St. Helen’s in Washington State and am using 14 ea. 6 volt deep cell batteries and inverter to run 120v. Just lights, TV’s , chargers and such. We run a generator to charge them and when new, a full charge would last a full weekend +. After 10 years (at about 6-8 weeks usage per year ) a full charge only lasts 3-4 hours now. Not complaining but I need to buy new batteries. I am wondering if I should stick to the 6V or go to something else. The batteries are constantly being run down and then charged up when in use. Space or weight is no problem. Would appreciate any opinions on this. I don’t know much about electricity and am always wondering if there is a newer system out there. Solar is not an option because we are in a heavily wooded area. Thanks!
Hi Jim,
It seems like most people are going with 12 volt lithium batteries when building large battery banks now. I would look into the 12 volt lithium options first.
You can check out this post on 12 volt lithium batteries for a few good recommendations.