11 Deep Cycle Battery – Which to Buy and What to Look for in 2021 (Complete Guide)

When you’re on a road trip or vacation, the last thing you want to deal with is a dead battery. Batteries power everything on your RV, and if you have a dud, you have a lot of cool features that don’t work.

But what should you look for when buying a deep cycle battery for your RV or camper? In this comprehensive guide, we’ll walk you through everything you need to know to stay powered and on the open road!

What Is a Deep Cycle Battery?

Deep cycle batteries are batteries that excel at providing power for as long as possible. While regular automotive batteries do a great job at starting your vehicle after it’s been sitting for a while, they need an alternator to charge them afterward.

While alternators still need to charge deep cycle batteries, they can last far longer between charges. This is an essential perk for RVs and campers as they power a ton of appliances from lights and your water heater to your stove and refrigerator!

Different Types of Deep Cycle Batteries

There are four main types of deep cycle batteries you can use for your RV or camper. Below we’ve broken these down and describe how they work.

Lead Acid Batteries – ExpertPower 12v 7ah

ExpertPower 12v 7ah
$22.11

This is the most common type of automotive battery. Our recommended.

09/17/2021 04:47 pm GMT

This is the most common type of automotive battery. They consist of lead plates covered in an electrolyte fluid known as sulfuric acid. This sulfuric acid, also known as battery acid, holds the electrical charge your battery uses to operate.

This process is how batteries have worked for over 100 years, and it’s an extremely reliable battery option. Since they are so common, they are easy to replace and have a lower up-front cost than any of the battery options out there.

They can deliver a ton of power over a short period of time, making them excellent options for short energy-intensive applications. However, while they have the lowest up-front cost, they also have a slew of disadvantages.

Chief among them is the fact that they don’t last as long as other battery options, so you’ll find yourself replacing them more often. Furthermore, they are temperature sensitive, and you need to set them up somewhere where driving conditions won’t move them often.

The liquid electrolyte solution needs to stay as steady as possible, and you always need to mount the battery upright to prevent the solution from leaking. While lead-acid batteries are notorious for needing maintenance (topping off the electrolyte solution), this isn’t always the case now.

They do offer maintenance-free sealed lead acid batteries that don’t require fluid top offs. Flooded batteries are heavier and bulkier than some of the other battery options out there, and they can lose up to 5 percent of their charge for every month they’re in storage.

While they are convenient and cheap, lead-acid batteries are far from the cream of the crop.

Pros

  • Lower cost than other battery options
  • Easy to replace and recharge when needed
  • Very powerful option that can deliver strong currents for a short period of time
  • Maintenance-free options (don’t require the addition of fluid)

Cons

  • Shorter life – do not last as long as other battery options
  • Temperature sensitive
  • Movement sensitive
  • Not all lead-acid batteries are maintenance-free
  • Heavier and bulkier than other RV battery options
  • Loses charge when in storage (up to 5 percent per month)

Gel Batteries – Optima Batteries 8020-164 35

Optima Batteries 8020-164 35
$229.99

This is one of the best gel batteries for your car.

09/18/2021 07:05 am GMT

Gel batteries are incredibly similar to lead-acid batteries. The main difference is instead of a liquid electrolyte, they utilize a gel solution. This solution is harder to spill than traditional flooded batteries.

Furthermore, gel batteries are always maintenance-free, and they are much more temperature resistant.

While you can set up gel batteries in any position, you should still install them in as level of a position as possible.

That’s because the gel solution still needs to encompass the lead plates, and the manufacturers don’t fill these batteries to the brim.So, if you don’t mount the battery in a level position, you’ll lose some of the battery’s effectiveness.

Another perk to gel batteries is they hold their charge in storage a little more effectively. While flooded batteries lose up to 5 percent of their charge per month, gel batteries only lose up to 3 percent of their charge in the same time period.

Moreover, gel batteries are more temperature resistant, so they can be exposed to more extreme temperatures and work properly. While there are several advantages to gel batteries over flooded ones, there are two distinct disadvantages.

First, their upfront cost is almost always higher. While you offset this cost with the fact that they typically last longer, this isn’t guaranteed. Furthermore, gel batteries require a special charger to recharge.

Gel batteries are far easier to damage, making it far more critical to invest in a high-quality gel battery charger. If you fail to recharge your battery correctly, you’ll end up with a dead battery far sooner than you should.

Also, if you’re stranded somewhere and can’t find a gel battery charger, you’ll be out of luck.

Pros

  • Hard to spill gelled electrolyte
  • Maintenance-free
  • Holds charge well when in storage (up to 3 percent loss per month)
  • Temperature resistant

Cons

  • Requires a special charger to avoid damaging battery
  • More expensive than flooded batteries

AGM Batteries – Interstate Batteries 12V 110 AH SLA/AGM

Interstate Batteries 12V 110 AH SLA/AGM
$249.99

Look at this one! AGM batteries are among the most popular for RV and camper enthusiasts for a reason. They offer tons of advantages and typically have a much longer service life.

09/18/2021 06:35 am GMT

AGM batteries work off the same concept as a flooded lead-acid battery, but how they do it is entirely different. AGM stands for absorbed glass mat, and that’s exactly how the battery works.

The battery utilizes fiberglass mats that absorb the electrolyte material. Since the solution is absorbed into these mats, you don’t have to worry about any accidental spillage or how you position the batteries.

Even better, they are more temperature resistant than either flooded or gel batteries, and they are completely maintenance-free. Like gel batteries, they have a low discharge rate while in storage, and they require a specialized charger to recharge the battery correctly.

Moreover, you can charge AGM batteries significantly faster than both flooded and gel batteries if you need to. However, you should still trickle charge these batteries to extend the service life as much as possible.

What truly makes these batteries so popular for both RVs and campers is that they work at much lower percentages before you need to recharge them. Where you need to charge flooded and gel batteries at 50 percent of their charge, AGM batteries work up to 80 percent.

This powers your accessories far longer than a traditional battery. While these batteries are far better for RVs than conventional lead-acid batteries, they do cost more upfront. Their long service life usually offsets this cost, but even if they don’t last long, the added convenience they offer makes them well worth the extra money.

Pros

  • Works at lower charger percentages (does not need to be fully charged to work)
  • Maintenance-free
  • Temperature resistant
  • Impossible to spill
  • Low discharge rate while in storage (up to 3 percent)

Cons

  • More expensive than flooded batteries
  • Requires a specialized charger to prevent damage while charging

Lithium-ion Batteries – Antigravity Batteries AG-801

Antigravity Batteries AG-801
$161.99

One of the most popular options. It is a very powerful battery that comes in a small package.

09/18/2021 04:14 am GMT

While flooded, gel, and AGM batteries all work off the same principles, lithium-ion batteries are completely different. They consist of three main components: the cathode, anode, and lithium salts. The lithium salts work in a similar way to the electrolyte solution in regular lead-acid batteries.

Lithium-ion batteries are among the gold standard for RV batteries. They have a super long service life and are maintenance free, so once you install them, you rarely have to think about them. Furthermore, they hold their charge in storage far better than even AGM batteries.

While they can lose up to 2 percent of their charge per month in storage, it’s far more common for them only to lose 1 percent of their charge.

Even better, the lower the charge, the less they lose. That makes it extremely unlikely you’ll pull the battery off the shelf and find it doesn’t work – even if it’s been a few years.

Another great perk is they are incredibly light, often half the size and weight of typical lead-acid batteries.

While lithium-ion batteries are one of the best choices you can get for your RV or camper, they have a few drawbacks. The biggest drawback is their price. They have a significantly higher upfront cost than flooded, gel, or AGM batteries.

However, since they can last up to 5,000 cycles, the battery’s overall cost is pretty low.

Another major concern is you can’t charge these batteries at near-freezing temperatures. While this might not be a problem in most areas, if you’re traveling up to Alaska, you might find you can’t get your battery recharged when you need it most.

Another major drawback is you shouldn’t put an extremely high load on these batteries when they are in a very hot environment. That’s because lithium-ion batteries can be a little thermally unstable, causing them to overheat and explode.

While this might sound like a significant problem, if you store the batteries in a location with a controlled temperature, like inside your RV, you’ll never have to worry about it. The key is not to overload the batteries while in an extremely hot environment (over 100 degrees Fahrenheit).

Pros

  • Long-lasting service life
  • Maintenance-free
  • Low discharge while stored (up to 2 percent)
  • Extremely light option

Cons

  • Extremely expensive up-front cost
  • Cannot charge at low temperatures
  • Temperature sensitive – use in lower temperature environments (under 100 degrees Fahrenheit) or they can explode, can’t charge battery at near-freezing temperatures

Final Considerations

Now that you know the difference between the most common battery options out there, you can take the time to break down exactly what you need. Below we broke down the four most common factors for you to consider.

Price

You can only buy what you can afford, regardless of what you want. That’s why the price is always the number one consideration. Flooded batteries are the cheapest up-front option, but lithium-ion batteries will save you money in the long haul if you can afford the upfront cost.

Where Will You Mount Your Batteries?

If you’re not mounting your batteries in a level location, you can automatically rule out flooded batteries. You should really rule out gel batteries too. That leaves both AGM and lithium-ion batteries to choose from. You can mount these batteries however you’d like!

Where Will You Use Your RV?

It’s one of the most critical questions you need to answer. If you’re only traveling in the continental US, a lithium-ion battery might be the perfect choice. But if you’re looking to take your adventures to the northern Canadian wilderness, an AGM battery might be the better choice.

You could say the same thing if you plan on hitting up the Mojave Desert or other areas with extreme temperatures. But you’ll also need to avoid flooded batteries if you’re planning on hitting up these locations as they can fail under extreme temperatures!

What Will Your Batteries Power?

If your RV has a ton of accessories, you should invest in higher quality batteries – and probably more of them. But if you’re just looking for a battery to start up a generator, then a flooded battery might be all you need.

Frequently Asked Questions

Your RV or camper battery is one of the most critical features of your vehicle. That’s why you want to get the right one the first time. It’s also why we know you have a ton of questions. We broke down and answered some of the most common ones below!

What deep-cycle battery is best?

While there are pros and cons to every battery type, if you are not going to expose your battery to extreme temperatures, lithium-ion batteries are the way to go. If you are in extreme temperatures, then AGM batteries offer more advantages.

Both flooded and gel batteries are lower quality options since they offer none of the advantages of AGM batteries and have more disadvantages. Outside of a lower price tag they offer no advantages.

How can you protect your RV battery?

There are a few different ways to protect your RV battery. First, you should store your battery at a stable temperature and disconnect it from any potential draws when in storage.

When using your battery, you should install it in a protected and level area – this is especially important if you’re using lead-acid or gel batteries.

Finally, you need to ensure you’re charging your battery properly to prevent damage. Trickle charges are better, and you need to make sure you remove the battery before you overcharge it. Some chargers do this for you. Other times you’ll need to monitor the charger yourself.

Furthermore, you need to select the correct charger for your particular battery. The same charger you use for a standard lead-acid battery won’t work for a lithium-ion battery and vice versa. Find the right charger for your battery.

Can you connect batteries together?

As long as the batteries are the same make and model, you can connect them in either series or series parallel. When connected in series, your battery will have the same overall voltage, and when connected in series-parallel, you add the voltages together.

Keep in mind the maximum amount of amperage you will need – as this is far more important than the amount of voltage. Connecting batteries is a great way to extend your batteries’ life before you need to charge them again.

Can you mix and match batteries?

Absolutely not. If you are connecting batteries, they need to be the same style, but the same make and model are even better. Mixing and matching different types of batteries is extremely dangerous.

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