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Best Deep Cycle RV Batteries (AGM, SLA, 12V, 6V) 2020

What Kind Of Battery Is Actually The Best For RV Use?

If your RV batteries won’t hold a charge anymore and you’ve started searching for new batteries online to figure out what’s the best option you’ve probably noticed that there is a ton of discussion about RV batteries and no one seems to really agree about which ones are the best.

Should you buy 12V, 6V, marine, AGM, or Lithium? There are so many options and ways to go. The honest answer to what type of battery is best for RV use is Lithium. But Lithium batteries are not budget-friendly and the average weekend camper just isn’t willing to shell out that kind of dough for batteries.

Related: Save 50% On Campgrounds All Over The United States With Passport America 

In this article, I’m going to review the best RV batteries that are not lithium. The first thing you may notice about my list is there are no marine batteries to be found. That is because while most marine batteries are technically deep cycle a lot of them are also “starting batteries” which means they are not true deep cycle batteries and will get damaged faster than real deep cycle batteries when being used.

You can use marine batteries in an RV and they may be all you can find at the local store. But if you’re searching for the best deep-cycle RV batteries that are lead-acid and will last a long time, marine is not the way to go.

Also, amp hours are a big deal when it comes to RV use. The higher the amp hours the less affordable the RV battery becomes. The most affordable deep-cycle RV batteries are around 35ah, this will be enough storage if you have two of them connected in parallel because it becomes 70ah in total. But it means you need to buy two.

Related: 6 Volt vs 12 Volt RV Batteries: The Pros & Cons Of Each

If you only want one 12V battery I would suggest getting something with at least 50ah. Otherwise, you will be draining your battery all the time and it will wear out faster.

Finally, space is an issue that needs to be addressed when buying new RV batteries. Make sure there is space for your new batteries in your RV. If you have a travel trailer like me and your batteries are stored in the front make sure the boxes they are stored in are large enough for the RV batteries. I’ll make sure to add links to the boxes that will fit each battery I review to make things easier.

ML35-12 - 12 Volt 35 AH SLA Battery- Mighty Max Battery Brand Product
Weize 12V 75AH Deep Cycle Battery for Wayne ESP25 WSS30V Backup Sump Pump, Trolling Motor, Solar System, Mobility Wheelchair, General Use
Best RV Battery
Universal Power Group 12V 100Ah Solar Wind AGM SLA DEEP Cycle VRLA Battery 12V 24V 48V
Vmaxtanks VMAXSLR125 AGM 12V 125Ah SLA Rechargeable Deep Cycle Battery for Use with Pv Solar Panels Smart chargers, Wind Turbines and Inverters and Backup Power (12 Volt 125Ah Group 31 AGM)
Universal Power Group 12V 200Ah 4D SLA AGM Battery Replacement for Solar Systems
Best 6V Option
VMAXTANKS 6 Volt 225Ah AGM Battery: High Capacity & Maintenance Free Deep Cycle Battery for Golf Carts, Solar Energy, Wind Energy.
Battery Type
AGM Deep Cycle
AGM Deep Cycle
AGM Deep Cycle
AGM Deep Cycle
AGM Deep Cycle
AGM Deep Cycle
Volts
12
12
12
12
12
6
Amp Hours
35
75
100
125
200
225
Watt Hours
420
900
1,200
1,500
2,400
1,350
LxWxH (inches)
7.68 x 5.16 x 7.13
10.24 x 6.65 x 9.17
12.17 x 6.61 x 9.16
12.9 x 6.8 x 8.7
20.75 x 8.11 x 9.65
9.5 x 7.3 x 11
Weight
23 lbs
46 lbs
64 lbs
75 lbs
114.6 lbs
71 lbs

ML35-12 - 12 Volt 35 AH SLA Battery- Mighty Max Battery Brand Product
Battery Type
AGM Deep Cycle
Volts
12
Amp Hours
35
Watt Hours
420
LxWxH (inches)
7.68 x 5.16 x 7.13
Weight
23 lbs
Weize 12V 75AH Deep Cycle Battery for Wayne ESP25 WSS30V Backup Sump Pump, Trolling Motor, Solar System, Mobility Wheelchair, General Use
Battery Type
AGM Deep Cycle
Volts
12
Amp Hours
75
Watt Hours
900
LxWxH (inches)
10.24 x 6.65 x 9.17
Weight
46 lbs

Best RV Battery

Universal Power Group 12V 100Ah Solar Wind AGM SLA DEEP Cycle VRLA Battery 12V 24V 48V
Battery Type
AGM Deep Cycle
Volts
12
Amp Hours
100
Watt Hours
1,200
LxWxH (inches)
12.17 x 6.61 x 9.16
Weight
64 lbs
Vmaxtanks VMAXSLR125 AGM 12V 125Ah SLA Rechargeable Deep Cycle Battery for Use with Pv Solar Panels Smart chargers, Wind Turbines and Inverters and Backup Power (12 Volt 125Ah Group 31 AGM)
Battery Type
AGM Deep Cycle
Volts
12
Amp Hours
125
Watt Hours
1,500
LxWxH (inches)
12.9 x 6.8 x 8.7
Weight
75 lbs
Universal Power Group 12V 200Ah 4D SLA AGM Battery Replacement for Solar Systems
Battery Type
AGM Deep Cycle
Volts
12
Amp Hours
200
Watt Hours
2,400
LxWxH (inches)
20.75 x 8.11 x 9.65
Weight
114.6 lbs

Best 6V Option

VMAXTANKS 6 Volt 225Ah AGM Battery: High Capacity & Maintenance Free Deep Cycle Battery for Golf Carts, Solar Energy, Wind Energy.
Battery Type
AGM Deep Cycle
Volts
6
Amp Hours
225
Watt Hours
1,350
LxWxH (inches)
9.5 x 7.3 x 11
Weight
71 lbs

Note: Scroll left/right on small screens to view all products in the table.

Mighty Max Battery 12V 35ah SLA Deep Cycle Battery

ML35-12 - 12 Volt 35 AH SLA Battery- Mighty Max Battery Brand Product

Check Price at Amazon

The ML35-12 12 volt 35 amp hour AGM deep cycle RV battery is an affordable option for RVers who like to have two 12 volt batteries connected in parallel. This is a very common set-up to have and one I use myself.  When connected this 35ah AGM deep cycle RV battery will end up being 70ah which is enough power to run general RV appliances like the water pump, lights, and fans for a day.

Two 12 volt batteries connected in parallel.

Like all of the batteries in this list, the Mighty Max is an SLA (sealed lead acid) battery made with AGM (absorbent glass mat) technology. AGM RV batteries are still technically wet batteries because they have acid in them but they are sealed so there’s no maintenance or need to refill them with water. They are also longer-lasting and a little lighter than traditional flooded lead-acid RV batteries.

The battery measures 7.13 inches tall including the terminals, 7.68 inches long, and 5.15 inches wide. Chances are these smaller RV batteries will fit in the original box or storage area in your RV.

See Also: Best Portable Generators With Wireless Remote Start

If you don’t have the right kind of weatherproof battery boxes or just want new ones the Camco Standard Battery Box (click to view on Amazon) is the perfect size with a little room to spare.

The battery weighs 23 lbs (10.5 kg) and it comes with the terminal screws necessary for securing wiring. Because they are AGM RV batteries you can mount them in any position. It’s also resistant to shock, vibration, and performs well under hot and cold temperature conditions.

The Mighty Max Battery 12V 35ah SLA Deep Cycle Battery is a great small AGM RV battery for those who don’t boondock/dry camp on a regular basis and like to stay in RV park and campgrounds with electrical hookups. That being said these will work for dry camping especially if you use two of them and you have a generator or solar panel you can use to charge them every day.

Pros

  • Affordable
  • AGM/SLA
  • True Deep Cycle Battery
  • Can be Mounted in any Position
  • Lightweight
  • Maintenance Free
  • Great for RVers who mostly camp with electrical hookups

Cons

  • Very Low Amp Hours (35)
  • Need to buy two for a decent RV set up
  • Will need to be charged daily to prevent damage

WEIZE 12V 75ah AGM Deep Cycle Battery

Weize 12V 75AH Deep Cycle Battery for Wayne ESP25 WSS30V Backup Sump Pump, Trolling Motor, Solar System, Mobility Wheelchair, General Use

Check Price at Amazon

The Weize 12 volt 75 amp hour AGM deep cycle RV battery is one of the more common sizes of battery you will find in RVs. Weighing 46 lbs it’s a good weight to carry around for one person and if you have two of them connected in parallel you will have 150 amp hours of power.

It measures 10.24 inches long, 6.65 inches wide, and 9.17 inches tall in total. It comes with the terminal screws and like all AGM deep cycle batteries, it can be mounted in any position and is shock and vibration resistant.

See Also: Best Portable Solar Panel Charger For RV Camper/Boondocking

The Weize RV AGM battery is a little taller than the 35ah battery but it will still fit in the Camco Standard Battery Box (click to view on Amazon).

When it comes to AGM deep cycle RV batteries what it really comes down to is what size you want and getting a brand you trust.

The WEIZE 12V 75ah AGM Deep Cycle Battery is a fantastic option for RVers who have a few solar panels or a generator they use when boondocking. You will be able to run your RV furnace for a few hours with these batteries but they will need to be charged almost every day with regular use.

Pros

  • Affordable
  • AGM/SLA
  • True Deep Cycle Battery
  • Can be Mounted in any Position
  • Maintenance Free
  • Great for RVers who often camp with electrical hookups

Cons

  • Will need to be charged daily to prevent damage
  • Fairly Low Amp Hours (75)

Universal Power Group 12V 100ah AGM Deep Cycle Battery

Universal Power Group 12V 100Ah Solar Wind AGM SLA DEEP Cycle VRLA Battery 12V 24V 48V

Check Price at Amazon

Now it’s time to start getting into the AGM RV deep cycle batteries that are great for dry camping, boondocking, and solar setups. The Universal Power Group 12 volt 100 amp hour AGM/SLA deep cycle battery has enough storage to keep your RV’s 12V appliances running without having to charge as often as you would with smaller RV batteries.

If you want to go all the way and connect two in parallel you will have 200 amp hours to work with. The larger RV batteries like this one are also better because you reduce the risk of getting your RV batteries so low you start to damage it.

All AGM batteries shouldn’t be run down more than 50% because after 50% sulfuric crystals start to build up on the internal plates and your battery will stop holding a charge over time.

See Also: Best Portable Quiet Inverter Generators For RV Camping

More storage means a larger battery. This 100ah AGM deep cycle RV battery weighs 64 lbs and is 12.17 inches long, 6.61 inches wide, and 9.16 inches tall.

It’s larger than your standard RV deep cycle batteries and you may need a larger box for it if your storage area is outside of the RV. The NOCO Group 24-31 Snap-Top Battery Box (click to view on Amazon) is plenty large with room to spare.

Like other AGM batteries, it’s shock and vibration resistant and can be mounted in any position. It’s also better for hot and cold weather than traditional flooded lead-acid RV batteries.

Universal Power Group 12V 100ah AGM Deep Cycle Battery is an awesome battery for any RV or solar set up and it’s large enough you only need one if you have a way to charge it when it gets down to 50%. I would suggest a battery of this size for people who boondock/dry camp more often than they camp with electrical hookups.

Pros

  • More affordable than batteries with slightly more amp hours.
  • AGM/SLA
  • True Deep Cycle Battery
  • Can be Mounted in any Position
  • Maintenance Free
  • Great for Boondockers/dry campers

Cons

  • Heavy
  • May not fit in standard RV battery storage boxes and spaces.

VMAX 12V 125ah AGM Deep Cycle Battery

Vmaxtanks VMAXSLR125 AGM 12V 125Ah SLA Rechargeable Deep Cycle Battery for Use with Pv Solar Panels Smart chargers, Wind Turbines and Inverters and Backup Power (12 Volt 125Ah Group 31 AGM)

Check Price at Amazon

VMAX is a well known and popular name among RVers and off-grid solar enthusiasts. They make some excellent AGM deep cycle batteries and their 12 volt 125 amp hour charge tank is no exception. Made mostly for use with renewable energy sources such as solar power and wind turbines this is a true deep cycle battery and not a marine “starting” one.

High storage deep cycle AGM batteries like these are fantastic for RVers, especially those who have a few solar panels on the roof. VMAX advertises a float service life span of 8-10 years. The float life is how long the battery will last under continuous charge and while RV batteries are rarely under continuous charge the lifespan will still be very high compared to lower quality AGM batteries and flooded lead-acid ones.

It comes with all the hardware required to attach your RV’s wiring.

Vmaxtanks VMAXSLR125 AGM 12V 125Ah SLA Rechargeable Deep Cycle Battery for Use with Pv Solar Panels Smart chargers, Wind Turbines and Inverters and Backup Power (12 Volt 125Ah Group 31 AGM)

See Also: Easiest Way To Use Solar Power In Emergencies/Power Outages

The VMAX 125ah is 12.9 inches long, 6.8 inches wide, and 8.7 inches tall. It fits in the group 31 battery size category and will fit in the NOCO Group 24-31 Snap-Top Battery Box (click to view on Amazon). It weighs a very considerable 75 lbs.

The VMAX 12V 125ah AGM Deep Cycle Battery is not nearly as affordable as smaller AGM deep cycle RV batteries but it has the high amp-hour storage capacity and the good name of VMAX to back it up. When it comes to batteries a good brand does matter and you want something you can depend on, especially if you camp out in the wild with no batteries stores around.

Pros

  • AGM/SLA
  • True Deep Cycle Battery
  • Can be Mounted in any Position
  • Maintenance Free
  • Great for Boondockers/dry campers
  • Awesome for solar set-ups

Cons

  • Heavy
  • May not fit in standard RV battery storage boxes and spaces.

Universal Power Group 12V 200ah AGM Deep Cycle Battery

Universal Power Group 12V 200Ah 4D SLA AGM Battery Replacement for Solar Systems

Check Price at Amazon

I’ve talked about all the best AGM deep cycle RV batteries that are a standard size and the most common for RV use but I thought I’d talk about another option for those who need a lot of power for their RV or home solar-set up.

The Universal Power Group 12 volt 200 amp hour AGM deep cycle battery is huge. Measuring 20.75 inches long, 8.11 inches wide, and 9.65 inches tall. This battery will barely fit on the front battery storage part of my travel trailer, but it’s perfect for the large front storage on a 5th-wheel or a motorhome, and you could boondock/dry camp for days without having to recharge.

It does weigh 114.6 lbs, which is a lot to carry for one person so you want to make sure you have enough people and lifting power to put it in place. The weight is the main downside for 12 volt batteries with lots of amp hour storage like this one. It’s the reason many people prefer 6 volt batteries in there RVs which is something I will talk about in the product below.

See Also: How To Do Laundry Efficiently When Boondocking Or RV Camping

It is the more affordable option for this much storage power, which is something to consider. You can also easily wire two of them in parallel which would give you 400 amp hours of power.

If your RV has the space, you boondock a ton, and have solar panels this is a fantastic option. It’s AGM so it can be mounted in any position and is shock and vibration resistant. It’s also a great option for home use as emergency backup power or for a solar set-up.

The Universal Power Group 12V 200ah AGM Deep Cycle Battery is a well-made battery and although it is very large and heavy it may be the perfect option for your RV.

Pros

  • AGM/SLA
  • True Deep Cycle Battery
  • Can be Mounted in any Position
  • Maintenance Free
  • Great for Boondockers/dry campers
  • Awesome for solar set-ups
  • An affordable option for large amp hour batteries.
  • Easy to wire two in parallel for RV use.

Cons

  • Extremely Heavy
  • May be difficult to find storage space for it in an RV

VMAX 6V 225ah AGM Deep Cycle Battery

VMAXTANKS 6 Volt 225Ah AGM Battery: High Capacity & Maintenance Free Deep Cycle Battery for Golf Carts, Solar Energy, Wind Energy.

Check Price at Amazon

Now for 6 volt RV battery option. There’s a lot of myths and stories surrounding 6 volt RV batteries and it can be hard to figure out if they are going to be a better option than 12 volt RV batteries. It’s true that 6 volt batteries can be slightly more durable and can withstand being charged and discharged more than 12 volt batteries but the main question is if it makes enough of a difference to choose this much less affordable option.

The most important thing you need to know is if you are going with 6 volt you have to buy at least two of them to run your RV. Just one will not work. The way 6 volt power combined in series works is two batteries will up the voltage to 12 volts but the amp hours will stay the same. So two of these 225 amp hour 6 volt batteries combined will still only give you 225 amp hours. That being said if you have four of them, which a lot of RVers do, you will end up with 450 amp hours.

You can read more about 6 volt vs 12 volt batteries in this article here and I won’t go too in-depth on the subject in this article. If you’ve decided on 6 volt batteries then the VMAX 6 volt 225 amp hour AGM deep cycle batteries are a fantastic choice.

See Also: Have An Instant Campfire With No Smoke & No Smelly Clothes

VMAX makes some of the best AGM batteries on the market today and they are a very popular choice for RVers. One battery is  9.5 inches long, 7.3 inches wide, and 11 inches tall. You will need to buy a different box for these if your previous RV battery set up was with 12 volt batteries.

The NOCO 6V Snap-Top Battery Box (click to view on Amazon) is a great option for single battery storage but you can also get large dual 6V battery storage boxes like the Camco Heavy-Duty Double Battery Box (click to view on Amazon)

One VMAX 6V battery weighs 71 lbs. The lighter weight of 6V batteries with the high amp hour storage is another reason 6V batteries are so popular with RVers. Because having two 71 lbs batteries is much easier to handle than one 114 lbs battery and you end up with the same amount of amp hours.

The VMAX 6V 225ah AGM Deep Cycle Battery is built to last and much like the 12 volt version, it is advertised to last 8-10 years on float service. It is an AGM battery so it can be mounted in any position and is shock and vibration resistant. If 6 volt is your preferred battery voltage, you can’t go wrong with VMAX.

Pros

  • AGM/SLA
  • True Deep Cycle Battery
  • Can be Mounted in any Position
  • Maintenance Free
  • Great for Boondockers/dry campers
  • Lighter than other 225ah battery set-ups
  • Will fit in most RV battery storage areas

Cons

  • Least Affordable Option
  • Must have two for RV use
  • If one fails RV will have no battery power

My Choice For Best Deep Cycle RV Battery

Universal Power Group 12V 100ah AGM Deep Cycle Battery

Universal Power Group 12V 100Ah Solar Wind AGM SLA DEEP Cycle VRLA Battery 12V 24V 48V

Check Price at Amazon

For an RV battery to be considered the best I have taken a few things into account. First, the amp hour capacity is a big deal because to make your AGM deep cycle batteries last as long as possible, you should do your best to not discharge them to a low state of charge very often or at all. A number that is often thrown around is 50%, which means that you should keep your batteries above half-full at all times.

Since the battery will lose some capacity each time it’s discharged, I recommend staying above 50% or higher if possible and recharging the battery to full on a regular basis. Therefore, if you have a lot of amp hours/useable power you are less likely to drain your RV battery past 50%, as long as you can recharge the battery regularly.

Things like affordability, durability, weight, size, and maintenance are also important.

The Universal Power Group 12 volt 100 amp hour AGM deep cycle battery has all of these things. Its got enough amp hours to make it a great battery for both boondockers and RV park campers. If you’re a boondocker you may want to use two connected in parallel and if you mostly camp connected to electricity then one will be just fine.

See Also: What To Do When An RV Waste Tank (Black/Grey) Won’t Drain

If you consider the number of amp hours you get the Universal Power Group battery is very affordable and it only weighs 64 lbs, which is fairly manageable. It’s also not much larger than your average RV battery and it should easily fit in the regular battery storage area with the exception of travel trailers, which will need a box that is slightly longer.

Because it’s AGM it’s maintenance-free, can be mounted in any position, is shock and vibration absorbent, and will last much longer than your old flooded lead-acid RV battery.


Frequently Asked Questions

What are cranking amps?

Cranking amps are a unit commonly associated with car and marine starting batteries. They are the number of amps a battery can output in 30 seconds at 32°F (0°C). The higher the cranking amps the better the battery will be at starting a motor in cold weather.

Cranking amps aren’t something you need to be worried about for RV batteries and if you are looking at a deep cycle battery that has the cranking amps listed chances are it’s a “starting” deep cycle battery and not the best option for RV use.

What does “ah” stand for?

AH or ah stands for “Amp Hours.” Amp hours are used to measure a battery’s capacity and are a popular unit used to categorize AGM batteries.

How do I calculate watt hours from amp hours?

To calculate watt hours you multiply the voltage of the battery by the amp hours. For example, a 12 volt battery with 100 amp hours will have 1,200 watt hours. A 6 volt battery with 100 amp hours will only have 600 watt hours.

Will my RV charger charge AGM batteries safely?

AGM batteries need to be charged with a good battery charger so they don’t get damaged. A battery charger with an AGM option is the best but most RVs don’t have smart chargers with battery type options in them. A lot of them do have 3 stage chargers that are suitable for AGM batteries.

You should be able to check what kind of charger is in your RV’s converter/charger in the manual. My 2013 Heartland Prowler has the WFCO WF-8900 Series in it which uses a 3 stage battery charger. You can’t choose the kind of battery on the charger but because it’s 3 stage it’s not going to damage the battery too much and I won’t bother changing the charger in it.

If you have an older RV I would recommend replacing the converter/charger. A good battery charger will not only charge your batteries safer and faster it will also extend the life of them which helps you save in the long run.

How long will my RV batteries run the furnace?

This is an excellent question that deserves a good response, so I made another post about how long an RV battery can run a furnace you can check out here.

Why is my RV battery not charging?

When it comes to RVs there are tons of things that can go wrong and the battery charger is no exception. If your RV battery or batteries don’t seem to be charging at all even when plugged into power the problem is most likely the batteries themselves.

The first thing you should do it check the terminals. They need to be clean and securely connected to the RV. Also, check the ground wire which will be attached to the frame somehow. If the ground wire has come loose the batteries won’t charge.

Some RV’s have a battery cut off switch, check your RV manual to see if you have one or not and if you do check to make sure it’s not turned off. If everything looks good it’s time to test the battery and the RV charger/converter.  For this, you will need an external battery charger. Unhook your RV from the batteries and attach the charger to the RV battery. If it starts to charge just fine then you know the problem is with the RV charger/converter.

The converter/charger is usually located under the fuse box. To you need to remove the cover to the converter. Before doing any of this make sure all power is disconnected from the RV including the batteries. Once all the power is off inspect the wires leading to the converter box to see if anything has come loose.

It’s pretty rare for an RV battery charger/converter to go bad but anything is possible. They can be replaced, all you have to do is find the model number and search for the correct replacement part. One last thing you should think about is the type of batteries you are trying to charge. Most RV chargers are not designed to charge Lithium-ion batteries. It could be why it’s not working.

If you want to replace the lead-acid batteries in your RV with lithium ones you will also need to replace the converter/charger. For WFCO WF-8900 series you can use this Lithium-ion replacement converter/charger (click to view on Amazon).

Why is my RV battery draining?

An RV uses 12 volt power for a large number of appliances in the RV, even when it seems like everything is turned off you may still find that your batteries are being drained. A common misconception is that only the lights and water pump use the 12V power, this isn’t entirely true. Even when turned to LP gas (propane) mode the RV fridge will use around 250 watts a day from the thermometers and electric starter. The water pump also uses electricity even when in gas mode to test the temperature and start the propane.

If it seems like your batteries are draining super fast every day it could be the batteries are damaged and not holding a full charge anymore. Draining deep-cycle lead-acid RV batteries past 50% will start to damage them and your batteries won’t hold a full charge over time. Temperature is also another draining factor. In cold weather, batteries will not be as efficient and you may lose more power when using 12V appliances in your RV.

Why is my RV battery boiling?

If you are getting a strong rotten egg smell from your RV batteries or you notice vapor coming out of them you may have boiling batteries. Boiling batteries only happen when the battery is receiving a charge of some kind. If your RV batteries are boiling unplug your RV from shore power or disconnect the charger if you have one attached. Wait until the acid has calmed down before opening up the battery and make sure to wear gloves and old clothes as battery acid is very corrosive and will damage any clothing it touches. It’s also dangerous on your skin so be careful.

Flooded lead-acid batteries need to be checked and topped off with distilled water regularly. If your battery is boiling when being charged by your RV the most likely cause is low water. Top off each cell with distilled water and plug the battery in again. If this hasn’t fixed the problem and the battery still boils you probably have a bad cell that was damaged from the lack of water and the battery will need to be replaced.

Where should I store my RV battery in the winter?

An RV battery should be stored indoors during the winter. There are different opinions about whether or not you should store an RV battery directly on cement, some say it drains them, others say it doesn’t matter. To be safe I always place the battery on cardboard or a few pieces of wood.

An important thing when storing an RV battery is to make sure it stays charged all winter long but don’t just hook it up to a trickle charger because overcharging can be just as damaging as letting a battery go dead. For winter storage you should use a smart charger like any of these (click to view post on best battery chargers). Smart chargers will not let your batteries overcharge and some even have a repair mode that will work to remove sulfuric crystal buildup and repair the battery.

When should I replace an RV battery?

Batteries go bad over time and they may get damaged faster if you often let them go below a 50% charge. If your batteries are no longer holding a charge you can try using a repair mode on a smart charger to boil the battery and remove the sulfur crystal buildup that has damaged your battery. If this doesn’t work it’s time to get a new battery.

How long does an RV battery last?

The life of an RV battery depends on the kind of battery, how well you maintain it, and how often it goes below the charge that will damage it. Traditional flooded lead-acid batteries are the most work to maintain and often go bad faster than sealed lead-acid batteries like AGM or gel batteries. That being said a well maintained flooded lead-acid battery that isn’t allowed to go below 50% charge should last for years and years. One that isn’t taken care of may only last as little as 1-2 years.

AGM and Gel batteries require no maintenance but they’re still being damaged a little bit each time they’re discharged. The deeper the discharge is, the more severe the damage is. Some companies boast their batteries can last up to 10 years when kept at a full charge which means you should get around 7 years of life from them if you don’t allow them to go below 50%.

To make an AGM or Gel battery last even longer I suggest getting a battery charger that has an AGM or GEL battery mode so it’s being charged the correct way. (click here to view a post on best smart deep cycle battery chargers). If you do happen to discharge an AGM battery down to 20%, the most important thing you can do is to quickly get it charged up again.

Lithium-ion batteries will last the longest even when being discharged to as low as 20-30% which is why they are so popular with solar and off-grid set-ups. If you want lithium-ion batteries for your RV make sure you change the RV charger/converter because an incorrectly charged lithium-ion battery will be damaged.

How to charge an RV battery from a vehicle?

When you plug your trailer into your vehicle it will automatically start charging. To charge efficiently the vehicle needs to be running.

How to charge an RV battery with a generator?

If you plug your RV into a generator the batteries will automatically start charging through the RV’s converter/charger. (Click here to view an article on how to plug an RV into a generator) If you have an external battery charger you can plug it into the generator and charge your RV battery this way.

Can an RV battery freeze?

Yes, an RV battery can freeze at 32°F if it’s fully discharged. That’s why if you are expecting cold weather you should make sure your batteries stay above a 50% charge. If extremely cold weather is in the forecast make sure to keep your RV batteries fully charged. That being said even fully charged batteries will freeze at -76°F, but that’s not really camping weather and not a very common temperature for places other than Antarctica and sometimes Alaska.

If your batteries have frozen make sure you let them thaw before trying to charge them again. Some people say that a battery that has been frozen should be replaced because it damages them and it may not be dependable anymore.

Can an RV AC run off the battery?

The short answer is no. A regular RV battery set-up can not run the RV AC. There are things you can do to make it possible to run an RV AC off of batteries but you need a powerful inverter and lots of battery and solar power to back it up.

See Also: The Best Camping Gas Generators That Will Run Your RV AC

Can you use an RV battery in a car?

A true deep-cycle RV battery will not be able to deliver enough power to start a car. That being said there are some hybrid deep-cycle marine batteries that are made to start boat engines, you may be able to get one of these to start a car but it’s not recommended.

Can you overcharge an RV battery?

Yes, you can overcharge an RV battery. If you plug your RV battery into a single or even a dual-stage battery charger and leave it over the winter it will start overcharging the battery which will damage it. Today most people use 3 and even 4 stage smart chargers to keep their RV batteries charged over the winter. These kinds of battery chargers know when to stop so the battery doesn’t get damaged. (click to view post on best smart battery chargers)

Many new RVs have smart 3 stage battery chargers in them so you won’t overcharge your RV batteries when plugged into shore power for a long time. Older RV’s may not have this. To see what kind of battery charger is in your RV check the converter’s manual. If you have a very old RV it may be a good idea to replace the converter/charger anyways since battery charging technology has come a long way over the years.

Also, if you are switching from lead-acid batteries to lithium-ion ones you will need the change the converter in your RV as most do not come with chargers that are capable of charging lithium-ion RV batteries.

How long will the RV battery last boondocking?

When boondocking or dry camping the amount of time the RV batteries will last entirely depends on how many amp hours each battery can hold and how much power you will be using. Remember, even the RV fridge will use power when on LP gas mode, and lights can drain a battery even if they are LED.

When boondocking for the first time keep a close eye on your battery so you get a good idea of how long it will last. You probably will end up using more power than you think and will end up needed to charge your batteries almost every day. To charge your RV batteries when boondocking you can use a generator (click to view post on best inverter generators), solar panels (click to view post on best solar panels that will charge RV batteries), and even electric power stations (click to view post on best electric power stations).

Have any more questions about RV batteries or deep cycle batteries? Leave a comment below.

2 thoughts on “Best Deep Cycle RV Batteries (AGM, SLA, 12V, 6V) 2020”

  1. Hi! I had a “deep cycle marine battery” sitting in my basement unused for the past four years. I charged it and used it camping two weekends ago to pump my air mattress (with inverter).. it worked! But by day 6, it couldn’t give enough juice to the inverter to pump the bed. (initial full-fill + about 12 partial-fills since we added air in the middle of the night).

    Does this sound like a reasonable charge the battery is providing, or is it showing its age? (I didn’t check water levels in the battery)

    Any advice?

    Reply
    • Hi Harry,

      To know for sure if your battery is holding a reasonable charge I would have to know how many amp-hours the battery is capable of holding. If it’s a small battery that doesn’t sound terrible but if it’s a large battery then it’s probably been damaged.

      If the battery was sitting in storage and wasn’t being maintained by a charger it probably has been building up a lot of sulfur ion crystals on the battery plates. This build up of crystals stops the battery from getting fully charged and if the crystals have been sitting on the inner plates long enough they may have damaged the plates permanently.

      If you use a battery charger with a repair mode like the NOCO Genius (click to view on Amazon) you can use it to try and remove some of the sulfur crystal build up on the battery plates. When using repair mode make sure the battery is filled with water before and after.

      Sometimes the repair mode won’t work on batteries that are too far gone but it’s something you can try before giving up and getting a new one.

      Reply

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