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Best Deep Cycle RV Battery (AGM, SLA, 12V, 6V) 2024

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

If your deep cycle RV batteries won’t hold a charge anymore and you’ve started searching for new batteries, you’ve probably noticed that there is a ton of discussion about what kind of deep cycle RV battery is best.

Also, no one really seems to agree on the best kind of battery or voltage.

Related Product: We use the reliable VMAX 100Ah AGM battery (click to view on Amazon) in our RV.

Should you buy 12 volt, 6 volt, marine, AGM, GEL, or Lithium? There are so many options and ways to go.

The type of battery that’s best for RV use is Lithium. You can read more about lithium RV batteries here.

The main problem with Lithium batteries is are not very budget-friendly and the average weekend camper just isn’t willing to shell out that kind of dough for RV batteries.

They are also require a different charger that isn’t usually installed in RVs.

In this review, I’m going to go over the best deep cycle RV batteries that are not lithium.

The first thing you may notice about my review is there are no marine batteries to be found.

It’s 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 for RV purposes.

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

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 camper battery becomes.

The most affordable deep cycle RV batteries are around 35ah.

That’s normally 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.

If you only want one 12V battery I would suggest getting something with at least 50ah.

Otherwise, you will be draining your RV house battery all the time and it will wear out faster.

Finally, space is an issue that needs to be addressed when buying new batteries for your camper. Make sure there is space for everything first.

If you have a travel trailer like me and your RV batteries are stored in the front make sure the boxes they are stored in are large enough for the type of deep cycle batteries you end up getting.

Related: How To Wire Multiple 12V Or 6V Batteries To An RV

I’ll make sure to add links to the boxes that will fit each battery I review to make things easier.

Summary (Links to Amazon)

ML35-12 - 12 Volt 35 AH SLA Battery- Mighty Max Battery Brand Product
UPG Universal Power Group 12V 100Ah Solar Wind AGM SLA DEEP Cycle VRLA...
Best Value
Renogy 12V 100AH Deep Cycle Hybrid Gel Battery, Over 750 Cycles,...
My Top Choice
Vmaxtanks VMAXSLR125 AGM 12V 125Ah SLA Rechargeable Deep Cycle Battery...
Renogy Deep Cycle AGM Battery 12 Volt 200Ah, 3% Self-Discharge Rate,...
Best 6V Option
VMAXTANKS 6 Volt 225Ah AGM Battery: High Capacity & Maintenance Free...
Battery Type
AGM Deep Cycle
AGM Deep Cycle
Hybrid Gel
AGM Deep Cycle
AGM Deep Cycle
AGM Deep Cycle
Volts
12
12
12
12
12
6
Amp Hours
35
100
100
125
200
225
Watt Hours
420
1,200
1,200
1,500
2,400
1,350
LxWxH (inches)
7.68 x 5.16 x 7.13
12.17 x 6.61 x 9.16
12.9 x 6.8 x 8.7
12.9 x 6.8 x 8.7
20.6 x 9.4 x 8.8
9.5 x 7.3 x 11
Weight
23 lbs
64 lbs
64 lbs
75 lbs
128
72 lbs
Battery Group
U1 (Will Fit In Most Group 24 Boxes)
27
31
31
n/a
n/a
Other Sizes Available (Click To View On Amazon)
55 / 75 /
100 / 200
35 / 55 / 75
35 / 60 / 100
none
Cycles at 50% Discharge
∼450
∼500
∼750
∼900
∼650
∼900
Self-Discharge Rate (monthly)
3.33%
3%
3%
4%
3%
4%

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
Battery Group
U1 (Will Fit In Most Group 24 Boxes)
Other Sizes Available (Click To View On Amazon)
55 / 75 /
100 / 200
Cycles at 50% Discharge
∼450
Self-Discharge Rate (monthly)
3.33%
UPG Universal Power Group 12V 100Ah Solar Wind AGM SLA DEEP Cycle VRLA...
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
Battery Group
27
Other Sizes Available (Click To View On Amazon)
35 / 55 / 75
Cycles at 50% Discharge
∼500
Self-Discharge Rate (monthly)
3%

Best Value

Renogy 12V 100AH Deep Cycle Hybrid Gel Battery, Over 750 Cycles,...
Battery Type
Hybrid Gel
Volts
12
Amp Hours
100
Watt Hours
1,200
LxWxH (inches)
12.9 x 6.8 x 8.7
Weight
64 lbs
Battery Group
31
Other Sizes Available (Click To View On Amazon)
Cycles at 50% Discharge
∼750
Self-Discharge Rate (monthly)
3%

My Top Choice

Vmaxtanks VMAXSLR125 AGM 12V 125Ah SLA Rechargeable Deep Cycle Battery...
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
Battery Group
31
Other Sizes Available (Click To View On Amazon)
35 / 60 / 100
Cycles at 50% Discharge
∼900
Self-Discharge Rate (monthly)
4%
Renogy Deep Cycle AGM Battery 12 Volt 200Ah, 3% Self-Discharge Rate,...
Battery Type
AGM Deep Cycle
Volts
12
Amp Hours
200
Watt Hours
2,400
LxWxH (inches)
20.6 x 9.4 x 8.8
Weight
128
Battery Group
n/a
Other Sizes Available (Click To View On Amazon)
Cycles at 50% Discharge
∼650
Self-Discharge Rate (monthly)
3%

Best 6V Option

VMAXTANKS 6 Volt 225Ah AGM Battery: High Capacity & Maintenance Free...
Battery Type
AGM Deep Cycle
Volts
6
Amp Hours
225
Watt Hours
1,350
LxWxH (inches)
9.5 x 7.3 x 11
Weight
72 lbs
Battery Group
n/a
Other Sizes Available (Click To View On Amazon)
none
Cycles at 50% Discharge
∼900
Self-Discharge Rate (monthly)
4%

Last update on 2024-05-22 / Affiliate links / Images from Amazon Product Advertising API

Best Deep Cycle RV Battery Reviews & Info

1. Mighty Max Battery 12V 35ah AGM 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, these 35ah AGM deep cycle RV batteries will end up being 70ah.

70ah is usually enough battery power to run general RV appliances like the water pump, lights, and fans for a day or two.

It’s about 840 watt hours, you can safely use around 50% of that power. Discharging any kind of lead acid battery below 50% can cause damage.

With AGM batteries like the Mighty Max, you can get away with discharging to around 30%, but I don’t recommend doing that often if you can recharge your RV batteries while camping.

See Also: How To Install Solar Panel On RV Roof & Connect To Battery

Two 12 volt deep cycle RV batteries connected in parallel.
12 volt travel trailer batteries and other deep cycle RV batteries are often placed side by side and connected in parallel.

Like all the camper batteries in this review, 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 terminal posts), 7.68 inches long, and 5.15 inches wide.

It’s a little smaller than a regular group 24 deep cycle battery commonly used on campers, but chances are they will fit in the original box or storage area in your RV or camper trailer.

See Also: Best Deep Cycle Battery Chargers Reviewed (12V, 6V, RV, AGM)

If you don’t have the right kind of weatherproof battery boxes, or just want new ones, the Camco Standard Group 24 Battery Box (click to view on Amazon) is the perfect size with a little room to spare.

Because it’s an AGM deep cycle battery, it’s fairly lightweight. It’s only 23 lbs (10.5 kg) and comes with terminal bolts for securing cables to the battery.

The Mighty Max AGMs are SLA RV batteries, which means you can mount them in any position.

They are also resistant to shock, vibration, and perform well under hot and cold temperature conditions.

The Mighty Max Battery 12V 35ah AGM Deep Cycle Battery is a great small SLA RV battery for those who don’t boondock/dry camp regularly and like to stay in RV parks 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.

Related: Best Portable Solar Panel Charger For RV Camper/Boondocking

PROS

  • Affordable
  • AGM/SLA
  • True deep cycle RV battery.
  • Can be mounted in any position.
  • Lightweight
  • Maintenance Free

CONS

  • Low Amp Hours (35)
  • Two required for a decent RV battery bank.
  • Will need to be charged often when boondocking.

I originally had a 75 amp hour deep cycle RV battery linked to in this review.

But 100ah deep cycle batteries have become so popular they are now a better value than 75 amp hour 12 volt batteries.

Instead of reviewing a 75ah option, I will be giving two 100ah options since they are more available and affordable.

2. Universal Power Group 12V 100ah AGM Deep Cycle Battery

UPG Universal Power Group 12V 100Ah Solar Wind AGM SLA DEEP Cycle VRLA...

Check Price at Amazon

Now it’s time to get into the AGM deep cycle RV batteries that are great for extended 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 them.

All lead-acid batteries, including SLA ones like AGM and GEL, shouldn’t be run down over 50%.

After 50%, sulfuric crystals start to build up on the internal plates and your battery will stop holding a charge over time.

It’s one of the biggest reasons batteries that are left unused for extended amounts of time often need to be replaced.

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 a group 27 battery that’s larger than your standard group 24 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 27 Snap-Top Battery Box (click to view on Amazon) is a great option.

Universal Power Group batteries are made with quality materials and they are a fantastic brand for any camper battery needs.

If you don’t want to go as large as the 100ah version reviewed here there are smaller options available like these 35 ah (click to view on Amazon), 55 ah (click to view on Amazon), or 75 ah (click to view on Amazon) options.

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.

The Universal Power Group 12V 100ah AGM Deep Cycle Battery is an awesome brand and size of deep cycle battery for any RV or solar set up.

It’s large enough you only need one so long as you have a way to charge it when it gets down to 50% while you’re boondocking.

It’s a great value with a decent amount of recharge cycles at 50% and a low self discharge rate.

I recommend this size of a deep cycle RV battery to people who boondock/dry camp more often than they camp with electrical hookups.

PROS

  • AGM/SLA
  • True Deep Cycle Battery
  • Can be Mounted in any Position
  • Maintenance Free
  • Great for Boondockers/dry campers
  • Low self-discharge rate.

CONS

  • Heavy
  • Needs a larger battery box than RV standard.
  • Fewer recharge cycles than other batteries in review.

3. Renogy Hybrid Gel Deep-Cycle RV Battery

Renogy 12V 100AH Deep Cycle Hybrid Gel Battery, Over 750 Cycles,...

Check Price at Amazon

Another fantastic type of deep cycle battery for RV use that’s not Lithium-ion is Gel.

Gel batteries are very similar to regular lead-acid batteries. They still use a lead-acid composition, the main difference is silica is added to turn the liquid sulfuric acid into a thick gel.

The gel doesn’t move inside the battery. It’s more stable, releases less fumes, and it’s resistant to leaks and vibrations.

Much like AGM batteries, Gel batteries are completely sealed. They are maintenance free and can be mounted in any position.

When compared to AGM batteries, the Renogy Gel deep cycle battery has a higher internal resistance, discharge capacity, high temperature resistance, and a longer lifespan.

As shown in the table, the Renogy Gel has a lifespan of 750 cycles from 50% discharge, that’s 250 more cycles than the other 100 ah RV battery in this review.

The Renogy hybrid Gel deep cycle battery measures 12.9 inches long, 6.8 inches wide, and 8.7 inches tall.

It’s a group 31 battery. Camco makes a large battery box for group 27-31 batteries (click to view on Amazon) the Renogy will fit into perfectly.

It has a very similar weight to the AGM battery in this review coming in at 64 lbs.

This is a 100 amp hour 12 volt deep cycle battery with 1,200 watt hours of capacity.

Renogy has really made a name for itself in the battery and solar world. They make top of the line products and are a name you can trust.

Since Gel batteries like this can handle more charge cycles (longer lifespan) and have a similar self-discharge compared to AGM batteries, I would chose this one over the 100ah AGM deep cycle RV battery in this review.

It can be charged by a modern RV power center, and it’s fairly budget friendly.

The Renogy Hybrid Gel Deep-Cycle RV Battery is a fantastic choice for any kind of RVer, even dry campers.

PROS

  • Gel/SLA
  • True Deep Cycle Battery
  • Can be Mounted in any Position
  • Maintenance Free
  • Great for Boondockers/dry campers
  • Low self-discharge rate.
  • Long Life (high charge cycle rating)

CONS

  • Heavy
  • Needs a larger battery box than RV standard.

4. VMAX 12V 125ah AGM Deep Cycle Battery

Vmaxtanks VMAXSLR125 AGM 12V 125Ah SLA Rechargeable Deep Cycle Battery...

Check Price at Amazon

VMAX is a well known 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 capacity deep cycle AGM batteries like these are fantastic for RVers, especially those who have a few solar panels on the roof and dry camp/boondock.

VMAX advertises a float service life span of 8-10 years. The float life is how long the battery will last under continuous charge.

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 also has a super high charge cycle rating. At 50% discharge it can recharge around 900 times. That’s way more than the other Gel and AGM batteries in this review.

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’s a group 31 battery size and will fit in the Camco Group 31 Battery Box (click to view on Amazon).

It weighs a very considerable 75 lbs.

The VMAX 12V 125ah AGM Deep Cycle Battery might not be as affordable as slightly smaller AGM deep cycle RV batteries, but the cycle rating and long lifespan make it worth it.

When it comes to batteries a trusted brand matters. RVers want something they can depend on, especially when camping out in the wild with no batteries stores around.

If 125 ah seems a little excessive but you like the VMAX quality, they make more sizes of AGM deep cycle RV batteries.

There are 35 Ah, 50 Ah, 100 Ah, 155 Ah, and even 200 Ah options (click links to view on Amazon).

PROS

  • AGM/SLA
  • True Deep Cycle Battery
  • Can be Mounted in any Position
  • Maintenance Free
  • Great for Boondockers/dry campers
  • Super long Life Span (high charge cycle rating)

CONS

  • Very Heavy
  • Might not fit in standard RV battery storage boxes and spaces

5. Renogy 12V 200ah AGM Deep Cycle Battery

Renogy Deep Cycle AGM Battery 12 Volt 200Ah, 3% Self-Discharge Rate,...

Check Price at Amazon

So far, I’ve talked about all the best AGM deep cycle RV batteries that are a standard size and the most common for RV use.

I want to add another option for those who need a lot of power for their RV or home solar-set up.

The Renogy 12 volt 200 amp hour AGM deep cycle battery is huge. it measures 20.6 inches long, 9.4 inches wide, and 8.8 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.

With this much battery capacity (2,400 watt hours), 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. 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 wiring together multiple smaller 12 volt or 6 volt batteries in their RVs which is something I will talk about in the product review below.

See Also: Best 12 Volt RV Lithium Battery Reviews + How To Charge

One benefit to the giant AGM battery is it’s the more affordable option for this much storage power.

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 a solar set-up.

The Renogy 12V 200ah AGM Deep Cycle Battery is a well-made RV battery.

It’s large and heavy, but it may be the perfect option for your camper or solar set up.

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

6. VMAX 6V 225ah AGM Deep Cycle Battery

VMAXTANKS 6 Volt 225Ah AGM Battery: High Capacity & Maintenance Free...

Check Price at Amazon

Now for 6 volt RV battery choice.

There are a lot of myths and stories surrounding 6 volt RV batteries.

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, does it make enough of a difference to choose this much less affordable option?

The most important thing you need to think about 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.

To get 12 volt power from 6 volt batteries you combine at least two in series to double the voltage to 12.

It’s different than combining two 12 volt batteries because the amp hours will stay the same.

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 cannot combine 3 6 volt batteries and connect them to an RV, it has to be even number like 2 or 4.

You can read more about 6 volt vs 12 volt batteries in this article here.

I won’t go too in-depth on the subject in this review.

If you’ve decided on 6 volt batteries then the VMAX 6 volt 225 amp hour AGM deep cycle batteries are a fantastic option.

See Also: Best Remote Start Generators – Portable & Inverter

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.

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.

Two 71 lbs batteries are 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
6 volt lead acid deep cycle rv battery next to a 12 volt AGM deep cycle RV battery
6 volt lead acid deep cycle battery next to a 12 volt AGM deep cycle battery.

Conclusion & My Recommendation For Best Deep Cycle RV Battery

Choosing the right size, make, and brand of deep cycle RV battery can be a challenge.

Going with a higher quality AGM or Gel battery over a traditional flooded lead acid marine should help you save in the long run.

They last longer, are more resistant to vibrations from travel, and weigh a little less.

Deciding on what size as far as amp hours go really depends on how much dry camping/boondocking you do.

If you have a solar panel that can recharge your RV house batteries daily, you can get away with a smaller size.

If you want to be able to camp for days without worrying about how much charge is left, a larger amp hour battery is going to be a better choice.

When it comes to 12 volt versus 6 volt, I recommend reading this article here (click to view) to help you make a decision.

Below is my recommendation for the best overall deep cycle battery for RV use.

Renogy Hybrid Gel Deep-Cycle RV Battery

Renogy 12V 100AH Deep Cycle Hybrid Gel Battery, Over 750 Cycles,...

Check Price at Amazon

For a deep cycle RV battery to be considered the best I have taken a few things into account.

First, the amp hour capacity is a big deal.

To make your RV deep cycle batteries last as long as possible, you should do your best to not discharge below 50% very often or at all.

For that reason, if you have a lot of amp hours/usable power, you are less likely to drain your camper’s battery past 50%.

Especially if you can recharge the battery regularly.

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

The Renogy 12 volt 100 amp hour Gel 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. If you mostly camp connected to electricity, one should 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 Renogy battery is very affordable.

Also, it only weighs 64 lbs, which is fairly manageable.

It’s not much larger than your average RV battery and it should easily fit in the regular battery storage area.

Because it’s Gel 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.

marine deep cycle rv battery that's not great for RV use
Marine deep cycle batteries aren’t the best for RV use since the aren’t as durable as true deep cycle batteries.

Frequently Asked Questions About Deep Cycle RV Batteries

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.

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?

The 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 Gel and 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 Gel and AGM batteries safely?

Gel and AGM batteries need to be charged with a good battery charger so they don’t get damaged.

A battery charger with an AGM or Gel 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 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.

I made another post about how long an RV battery can run a furnace you can check out here.

Why isn’t my deep cycle RV battery charging?

With 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 is 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 campers 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 one of the RV batteries.

If it starts to charge just fine then you know the problem is with the RV charger/converter.

The RV converter/charger is usually located under the fuse box. To you need to remove the cover from 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).

Note that if you go with lithium RV batteries and you replace the converter/charger you may not be able to switch back to traditional lead acid batteries later on.

To read more about lithium RV batteries and find out how to charge them check out this article here (click to view).

Why is my deep cycle 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 camper’s house 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 for the thermometers and electric starter.

The water heater 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 deep cycle 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.

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.

rv deep cycle agm battery being stored inside connected to a smart battery charger for winter storage
AGM RV deep cycle battery being charged by a smart battery charger and stored in a garage for the winter.

Where should I store my deep cycle 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.

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 camper batteries are no longer holding a charge you can try using a repair mode on a smart charger.

It will 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 one.

How long does a deep cycle RV battery last?

The life of an RV battery depends on the kind it is, 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 deep cycle 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.

You can check out the best options for RV lithium batteries and read more about how to charge them here (click to go to article).

How to charge a deep cycle 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.

Luckily, that’s not camping weather and not a very common temperature for places other than Antarctica and sometimes Alaska.

If your batteries are 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.

If you have lithium-ion batteries you should never try and charge them in temperatures below 41°F.

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.

There are, however, portable generators that are powerful enough to run an RV AC. You can check out the best ones in this article here.

Can you use a deep cycle 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 some hybrid deep-cycle marine batteries 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 and when to start again 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, you will need the change the converter in your RV.

Most do not come with chargers that are capable of charging lithium-ion RV batteries.

How long will a deep cycle RV battery last when 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 need 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 deep cycle RV batteries or AGM batteries? Leave a comment below.

by Jenni
Jenni grew up in a small town in Idaho. With a family that loves camping, she has been towing trailers since a very young age.

10 thoughts on “Best Deep Cycle RV Battery (AGM, SLA, 12V, 6V) 2024”

  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
  2. Hi Jenni,

    First, great articles! Very helpful and informative.

    I have a general question about winter storage and batteries:

    We have typically kept our RV plugged into shore power at our house during the winter (we live in upstate NY of that makes a difference).

    Is this not a good idea? We don’t use the camper and shut off the fridge and winterize the water heater etc.

    Would it be better to get one of the smart chargers you mentioned?

    I haven’t seen a loss in any battery power, but, then again, we normally go from the house shore power to being plugged into the vehicle to being plugged into shore power at the campground.

    We do however, plan to eventually do some dry camping / boondocking at some point, so I wouldn’t want to destroy my battery. It’s also a new camper that we got the end of last season (2020).

    Thanks!

    Angelo

    Reply
    • Hi Angelo,

      An RV that’s that new most likely has a good converter/battery charger on it. I think you’re fine to leave the RV plugged in over the winter like you’ve been doing, especially since you’ve never seen any negative effects.

      I think most people remove the RV batteries and charge them elsewhere because they don’t have a way to get power to where the RV is stored.

      The low winter temperatures shouldn’t be much of an issue unless you have lithium batteries. Charging lithium batteries in temperatures below 40°F can damage them. But regular deep cycle RV batteries don’t have that problem.

      I would keep doing what you’re doing, it sounds fine to me.

      Reply
  3. Oh my gosh, this stuff is so interesting but is making me crazy at the same time. So, I’d love to get a 100ah lithium battery, but don’t understand the ins/outs of the charging the battery without hurting the alternator of tow vehicle. My simple understanding is that d/t lithium batteries charging at a lower rate (loss for words) the alternator on tow vehicle will have to work harder, possibly damaging it. I’ve read there is a converter or some such device that you can put in between alternator and lithium battery, but oh my…

    So, I decide on just getting a 100ah deep cycle battery to keep it simple and then read your comment on “Will your RV charge an AGM battery safely” and here we go again. My darn manual to my 2019 keystone hideout is so generic I can’t find what the actual converter/charger is on it. Perhaps, I’m not looking in the right place, but I went through every page of ‘electrical’ and nothing.

    Can I assume since it’s a 2019 model, I’m safe? Or does the ole cliche regarding assuming come to play here?

    Nick

    Reply
    • Hi AZNick,

      A 2019 Hideout should have a decent battery charger on it but just to be on the safe side can you tell me what the model number on the power converter/charger is? It should be somewhere near the fuse panel or even on the door of the fuse panel.

      Reply
  4. Hi Jenni, store trailer at buddy’s house and went over yesterday before reading this. However, I did grab my bag with all the information for my trailer in it and it appears I have the “WFCO Ultra III Power Center – model WF-8735P or WF-8740P”. Manual is for both.

    Thanks for educating me on this!

    Nick

    Reply
    • Hi Pat,

      AGM batteries are generally considered safe to have inside RVs. Many people store them in the storage under the bed or dinette seat.

      While they don’t usually emit any gases it can happen. So adding a little bit of ventilation could be a good idea for safety.

      Reply

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