12 Best Deep Cycle RV Batteries On The Market Today

It’s pretty accurate to say that a portable battery is perhaps one of the most important aspects of an RV. A deep cycle battery allows you to run all your electrical appliances without the need to connect to a 110-volt power supply.

An RV battery serves a number of utilities. It helps to pump water into the fresh water tank, runs the air conditioning or space heater and keeps your refrigerator nice and cold. Pretty much everything inside the RV runs on electricity, making a portable battery the beating heart of an RV.

However, most people don’t really understand which RV battery they need to use or how to use it. Different RVs call for different types of batteries if you want to maximize utility.

In this article, I’ll give you an overview of the 12 best RV batteries on the market. I have compiled this list after thoroughly vetting the best and most reputable RV batteries on the market and consulting with some RV experts.

Best Lithium-Ion RV Batteries

1. Renogy Lithium-Iron Phosphate Battery

The Renogy Lithium-Ion Phosphate Battery is my choice for the best lithium-ion RV battery on the market. Like most lithium-ion batteries, this model comes at a pretty steep price. However, if you’re looking for heightened portability owing to lightweight construction and a great lifespan, it’s well worth it.

This 12V RV battery has a capacity of 100Ah and an inbuilt battery protection system. This feature is of particular interest to me as it negates the need for regular maintenance. Essentially, this Renogy battery has a system to protect the cells for thousands of cycles and keep them running optimally.

The battery lasts about 10 times as long as a regular lead-acid battery. It can hold its power for an entire year if used under the right conditions. However, you must not drain the battery more than 90% of its capacity. Doing so will inevitably damage it.

In terms of charging, you should ideally use a LIFEPO4 110 Volt charger or Solar LIFE PO4 compatible charge controller. Under no circumstances should you use a trickle charger which is generally used for a car battery.

Pros

  • Has a great battery life, about 10x as long as a regular lead-acid battery
  • Has an expected lifespan of 7,000 cycles
  • At 28 pounds, it’s extremely lightweight
  • Internal battery protection system provides cell protection, overcharge, over-discharge, and short circuit protection

Cons

  • It’s one of the most expensive RV batteries on the market

2. Battle Born LiFePO4 Deep Cycle RV Battery

The Battle Born LiFePO4 Deep Cycle RV Battery is yet another lightweight lithium-ion RV battery with a capacity of 100Ah. Like the Renogy battery, this one too has a lifespan greater than most RV batteries.

However, at 3,000 to 5,000 cycles, it cannot compare to the Renogy’s enviable 7,000 cycles lifespan. You can read more about it here.

This battle born battery also has a great depth of discharge. After going to 100% discharge for up to 3,000 cycles, the battery’s capacity only decreases by around 20%. However, it is still recommended not to discharge the battery 100%.

This model has a great BMS to monitor the temperature, voltage, and current. One of the prime benefits of the BMS is that it disconnects loads automatically when a cell in the pack dips past the minimum recommended voltage. With a pack capacity of 100Ah, the measurement is taken from low voltage to full charge. Based on that rated capacity, the BMS enters the low voltage disconnect point when there is 0% remaining.

While charging, the bulk charging voltage should be between 14.2V – 14.6V and the float voltage should be below 13.7V.

Pros

  • High capacity while being considerably smaller in size than other batteries
  • Can be safely discharged to 90%
  • Can also be discharged at a high current rate without affecting the capacity
  • It can be installed indoors as there’s no risk of leaking or hydrogen generation
  • Has greater output voltage than most other batteries
  • With 3,000 to 5,000 cycles of lifespan, it can last for several years
  • Can hold the charge for over a year without leaking

Cons

  • It’s one of the more expensive lithium-ion RV batteries
  • The cells are made in China

Best AGM RV Batteries

3. Renogy Deep Cycle AGM Battery

The Renogy 12V 100Ah Deep Cycle AGM Battery is extremely versatile and multi-functional. This is one of the prime reasons why I’ve placed it at the top of my selection of best AGM RV batteries. In addition to using it as a battery for RVs, it can also be used for golf carts, consumer electronic goods, motorcycles, and engine starters, to name a few.

The discharge on these batteries should not exceed 50% as that could seriously damage its service life and capacity. A 50% discharge limit might seem poor compared to lithium-ion batteries, but it’s normal for AGM batteries.

If you’re going off grid with your RV, you should ideally hook up two of these batteries in parallel. If necessary, you can also use 200 W of Renogy solar panels to keep them charged. That should provide enough power for several weeks.

Pros

  • This AGM RV battery serves multiple purposes
  • Can be used for backup power on a daily basis
  • No risk of spills or leaks and minimal need for maintenance
  • Has a system in place to prevent over-charging of batteries

Cons

  • The biggest issue with this RV battery is that it’s extremely large and heavy at 70 pounds. Before purchasing it, make sure you have enough space.

4. Optima 8016-103 D34M BlueTop Battery

The Optima 8016-103 D34M serves as both a deep cycle and a starter battery. This dual function makes it one of the most impressive AGM RV batteries on this list.

This 12V deep cycle RV battery lags behind some of the others with a 55 Ah capacity. As such, it can only last half a day on a single cycle. However, it is sturdy and durable. Furthermore, owing to its SpiralCell design and continuous lead plates, it provides power even in harsh weather conditions.

Several users have commented on how this battery can start the engines of RVs and boats instantly, in addition to powering all their RVs electrical appliances. It is also completely safe with no risk of acid spills or corrosion.

If you drive your RV in shaky conditions, you might be concerned about the effect that vibrations might have on the battery. The Optima 8016-103 is considerably more vibration-tolerant than other AGM batteries on the market.

Pros

  • Functions both as a starting and a deep cycle battery
  • Compared to other AGM batteries, it’s quite light at 43.5 pounds
  • Has a high reserve capacity
  • About 15 times more vibration resistant than other marine batteries
  • No risk of spills or corrosion

Cons

  • Gets damaged easily upon being hit
  • Some users complain that it fails to hold a charge after a few months

5. VMAXTANKS 6 Volt 225Ah AGM Battery

Do you want to drive your RV off-grid for long periods of time without having to charge the batteries? If so, the VMAXTANKS 6 Volt 225Ah AGM Battery is a good option for you. At 225 Ah, this AGM battery has over twice as much capacity as most of the RV batteries on this list.

One of the big constraints here is the presence of a mere 6V of power. However, you can connect two 6V batteries in a sequence and the amp hours remain unchanged. This can be achieved simply by wiring the negative terminal of one of the batteries to the positive terminal of the other.

Next, you have to wire the output — either from an inverter or a 12V load — to both the positive terminal of one and the negative terminal of the other. However, if you want to increase the capacity, you’ll have to connect them in parallel rather than in series.

Once you set it up, there’s no need for additional maintenance of the battery.. There’s no need to either check the electrolyte solution or add water, nor is there any provision for that. It has a float service lifespan of 8 to 10 years. However, in order to maintain optimal quality, the battery should never be discharged below 50%.

Pros

  • Higher capacity than most RV batteries
  • Can easily be connected in a series to increase the voltage
  • Requires no maintenance
  • Has a tremendous lifespan

Cons

  • Like most AGM batteries, you cannot let it discharge below 50%. This risks harming the battery’s lifespan and capacity.
  • At 72 pounds, it’s one of the heaviest RV batteries out there. As such, it’s important to make sure you have enough space for it, especially if you’re getting two batteries for a series.

6. Odyssey PC680 Battery

The Odyssey PC680 is a 12V battery with a lightweight but rugged construction. Even though it only weighs 15 pounds, it has an extremely high vibration tolerance. Furthermore, it can withstand constant pounding from elements like snow, hail, or rain.

You should take note that the Odyssey PC680 comes with L terminal adapters on Amazon. As such, you don’t need to purchase them separately. The batteries also come fully charged so you can immediately set them up and start using them.

One of the great benefits of getting an Odyssey battery is its lifespan. The company advertises that their battery lasts up to 10 years. While I have yet to encountered any users who have made it last for the full 10-year period, most still report a lifespan of about 7-8 years. This is still a pretty impressive, I must say.

Furthermore, the Odyssey battery has a depth of discharge of 80%. this is a marked improvement over most AGM batteries that have a depth of discharge of about 50%.

Pros

  • Has a 70% longer lifespan than most RV batteries
  • Vibration resistant, temperature-tolerant, and durable
  • Can recharge completely in 4 to 6 hours
  • Has a high depth of discharge

Cons

  • Lacks technical support. Several users have complained about poor customer service.

7. Universal UB121000-45978 Deep Cycle AGM Battery

The Universal UB121000-45978 is a 12V 100Ah AGM RV battery. The battery is completely sealed so there’s no risk of spillage or leaks, and it requires minimal maintenance.

One of the biggest issues with this battery is that it doesn’t hold the optimal voltage for a long time. After a few months, you might find that the voltage on full charge drops to 11 or even 8 volts.

A healthy battery should be able to carry at least 12.4 volts effortlessly. I guess you could say that the Universal UB121000 battery, while cheap, isn’t very durable.

It has a depth of discharge of 50%, and that can take you through 500 cycles. However, if you allow the discharge to go beyond this point, your battery’s life cycle will be compromised drastically.

If you discharge it completely, you might only get 200 life cycles. However, if you maintain an average discharge of 30%, you can even stretch it for 1200 life cycles.

Pros

  • Requires no maintenance
  • Shock and vibration resistant
  • Decent life expectancy of up to 5 years

Cons

  • At 60 pounds, it’s quite heavy
  • The battery only works to optimal capacity for a few months. After a while, the capacity decreases or it fails to carry enough voltage, even on a full charge.

8. VMAXTANKS V35-857 AGM Marine Deep Cycle Battery

The VMAXTANKS V35-857 is a 12V 35Ah AGM RV battery. Weighing just about 18 pounds, this is one of the most lightweight and portable deep cycle batteries on the market.

This battery only has a 35Ah capacity. Considering the industry standard for an RV battery is 100Ah, that’s pretty low. To make up for the low capacity, you have to connect several batteries in parallel.

You might wonder why anyone would buy batteries at such low capacity. That’s primarily because these VMAXTANKS batteries feature high performance military grade plates. This results in thicker plates that are more durable and resistant to vibrations and other external factors.

These batteries have a depth of discharge of 40 to 50% and a single cycle takes you through 4 to 5 hours of use. If you intend to go off-grid with your RV, you’ll need to purchase severa. If not, you’ll have to recharge them constantly.

Pros

  • Extremely durable military grade plates
  • Requires no maintenance and there’s no risk of spillage or leaks

Cons

  • In order to make up for the low capacity, you have to purchase several of these batteries and connect them
  • A single life cycle only provides 4 to 5 hours of power

9. Lifeline Marine AGM Battery

The Lifeline Marine is a 6V 220Ah AGM RV battery. The biggest advantage here is the exceptional run time and recharge rate. At 220Ah, it has a lot more capacity than most deep cycle batteries. This ensures that you can use the battery for an extended period of time without having to charge it.

The limited voltage of 6V can be easily overcome by combining two in a series. This can be achieved by combining the positive terminal of one battery to the other’s negative terminal. Next, you connect the positive and negative cables of the boat to the unused battery terminals, thereby turning them into a 12V 220Ah battery.

However, the Lifeline Marine battery is also pretty heavy at 66 pounds and has fairly large dimensions of 10.3 x 7.1 x 9.9 inches. As such, combining two batteries would take up a lot of space. If you intend on using it in your RV, be sure that you have enough space for both of them.

Furthermore, this are one of the few AGM batteries that can be equalized. The battery comes with the instructions on how to do it. However, equalization is only necessary when the battery is not returned to full charge after a discharge. Equalizing the battery can increase its lifespan.

Pros

  • Exceptional run time and recharge rate
  • Has a high capacity and thus can run for long periods of time without needing a recharge
  • Two batteries can easily be connected in a series to get 12 volts
  • They can be equalized

Cons

  • Large and heavy, so needs a lot of space.

10. WindyNation BattaMax

The WindyNation BattaMax is a 12V 100Ah AGM RV battery. It weighs around 67 pounds and has a life expectancy of 10 to 12 years in float mode. This lead-acid battery is perfectly sealed, preventing all possibilities of spills or leaks. It’s perfect for use as an RV battery or for solar charging.

The body of the battery is made of 99.9% pure lead to contain all self-discharges. This also ensures that the battery is shock resistant, and it helps optimize its life cycle.

It’s quite reasonably priced. Instead of buying high capacity batteries, a lot of users prefer buying a series of these batteries and connecting them in parallel. Connecting four in parallel would attain a capacity of 400Ah. Furthermore, the cost of all four would still be lower than a single lithium-ion battery.

The WindyNation BattaMax comes with an RV solar kit, complete with a reliable power source and off-grid applications.

Pros

  • Reasonably priced
  • Can be easily connected in parallel to increase capacity
  • Made of pure lead to prevent spills or leaks
  • Long lifespan in float mode
  • Complimentary RV Solar Kit provided

Cons

  • Large and extremely heavy

11. XS-Power-D3100

The XS-Power-D3100 is a 12V 110Ah AGM RV battery. This is perhaps one of the largest AGM batteries on this list. It has dimensions of 16.8 x 11.8 x 10.5 inches and weighs 79 pounds. You can read more about it here.

Some users have reported that the battery’s body swells up under hot weather conditions. If you intend to use your RV in extremely hot or extremely cold conditions, this battery isn’t the right choice.

Another major concern is that it has been officially rated as a 5000-watt battery. However, it should actually be rated as a 3000-watt battery, as it experiences a voltage drop when taken to the limits.

Pros

  • Powerful battery with a great capacity

Cons

  • Extremely heavy and large
  • Not very durable or weather-resistant
  • Wrongfully rated as a 5000-watt battery

12. Odyssey PC925 Battery

The Odyssey PC925 is a 12V AGM Battery with an extremely long lifespan of up to 10 years. At an 80% discharge, this battery can still give you 400 life cycles. That’s approximately 70% better than most AGM batteries on the market.

One thing you should be careful about is the battery’s terminals. Depending on the specific model you order, the positive and negative terminals might be switched from left to right. Be sure to order the model with the terminals how you want them to be.

Some users have stated that this battery should not be left idle. If you leave it idle and unused for a few weeks, you might find that it stops working altogether, despite being fully charged. Of course, it might work, but its life cycle or capacity will be drastically compromised.

Pros

  • Powerful battery with a long lifespan
  • Can be recharged completely within 4-5 hours
  • Shock, vibration, and extreme temperature resistant

Cons

  • Extremely heavy
  • Needs to be used regularly or it might lose efficiency

RV Batteries Buyer’s Guide

As important as RV batteries are, a lot of people lack crucial information about them. In this section, I’ll give you a detailed 101 session on RV batteries. You’ll know exactly what to look for when you’re getting a new battery for your camper or RV.

What is an RV Deep Cycle Battery?

Pretty much everything inside an RV runs on a deep cycle battery, be it your TV, AC, space heater, refrigerator, or anything else.

An RV deep cycle battery shouldn’t be confused with a starting battery. The latter provides a burst of energy to get the vehicle engine started while the former, the RV deep cycle battery, provides a steady flow of power over an extended period of time.

An RV battery is designed in such a way that it discharges up to 80% of its capacity, depending on the type of battery in question. Once the batteries have discharged, they need to be recharged, so that energy can be re-deposited. The process continues and the RV deep cycle battery provides power to your RV for a long period.

The Different Types Of RV Batteries

There are a number of RV batteries to choose from. Two of the most commonly used are AGM and lithium-ion. In this section, I’ll give you a brief intro to all RV battery types.

Lead-Acid Batteries

First off, what’s this lead-acid stuff? Batteries for automotive, marine and RV use internal lead plates and the action of sulfuric acid to generate electricity, which gives them the name lead-acid.

Think of a battery as holding a certain amount of electricity. A lead-acid battery is rechargeable, which means it is constructed to discharge electricity during use and can then be recharged to its former level or amount of electricity. Proper discharging and charging helps extend the life of the battery.

Lead-acid batteries are designed to produce a specific voltage: 6V or 12V. Think of voltage (the unit is the Volt and uses the symbol V) as being like pressure from a garden hose. 12V is twice the pressure of 6V. Amperage (Ampere or Amp, symbol A) is the rate of flow of electricity. Think of 10A as being a gusher and 0.1A as a trickle.

According to Interstate Battery Systems International, lead-acid batteries can be grouped into two types:

  • Deep cycle batteries are engineered to be deeply discharged hundreds of times. A deep discharge is defined by Interstate as one that drops the charge by 40% or more. For a 12V battery, this means a drop to 7.2V or less.
  • Automotive starting batteries (also called starting/lighting/ignition or SLI batteries) are designed specifically to provide a short burst of high-amp energy and to do this thousands of times over the product’s lifetime. They may be able to deeply discharge only a few dozen times before damage results.

Both types of batteries must be appropriately recharged after each use. A discharge and subsequent recharge is called a cycle. A deep-cycle battery is engineered to endure repeated deep discharges and recharges. A starting battery is built to endure repeated intense shallow cycles.

Flooded Lead Acid vs Sealed Lead Acid Batteries

Marine/RV lead-acid deep-cycle and starting batteries come in two types: flooded (FLA) and sealed (SLA).

Flooded or liquid-electrolyte batteries:

  • Contain a free liquid sulfuric acid solution
  • Have vent caps to allow gas discharge (gasses formed from evaporation and during charging are vented into the atmosphere)
  • Can spill acid if tipped or shaken
  • Tend to corrode around the electrodes
  • Require regular inspection and maintenance
  • Require care for safe transportation and storage

Maintenance of an FLA battery includes cleaning corroded electrode posts, checking electrolyte levels, and adding distilled water when necessary to top off. Car motor starting batteries can be the liquid electrolyte type because they are usually easily accessible for servicing.

Sealed lead acid (SLA) batteries:

  • Do not expel external gases (the gases are recombined internally)
  • Do not leak
  • Do not require maintenance or inspection
  • The reduction in maintenance is attractive to many consumers. And for some RVs, a sealed starting battery may be preferred if it is in a difficult location.

Flooded/ Wet

In these RV batteries, the plates are immersed in an electrolyte fluid. While being charged, they release hydrogen and oxygen and thus need to be well vented.

Going by the aforementioned factors, it’s clear that flooded/Wet RV batteries are pretty high maintenance. However, they make up for the effort by providing a long lifespan and lower cost.

The drawbacks of flooded RV batteries are the necessity of regular upkeep and the potential for gas buildup or spillage.

AGM

AGM is short for absorbed glass mat batteries. These are the most popular RV batteries for a number of reasons.

First, these batteries are sealed, which means there’s no need for venting. Second, the electrolyte is absorbed in the fiberglass mats, so there’s no potential for spillage. Third, AGM batteries coperate in any position and are low temperature resistant.

And finally, they charge quickly and are easy to store. All of these factors taken into consideration make AGM batteries low maintenance.

AGM batteries only come with one drawback — the potential for overcharging. However, this issue can be easily remedied by using a charge controller.

Lithium-Ion

Lithium-ion batteries are quite popular, although they’re some of the most expensive RV batteries out there. Having said that, they are lightweight, charge efficiently and resistant to both high and low temperatures.

Lithium-ion batteries use Lithium iron phosphate (LiFePO4), a safe chemical compound that increases the battery’s lifespan.

Gel

Gel batteries are some of the oldest types of RV batteries. The electrolyte is mixed with silica to create the gel. Gel batteries are riddled with a number of drawbacks however. They take a long time to charge and need a very specific amount of charge. You need a charge controller to prevent overcharging and also ensure the controller is compatible with gel batteries.

Deep-Cycle RV Battery Ratings and Specifications

Automotive lead-acid batteries have certain ratings that the manufacturer usually prints on the label. These ratings specify how much power the battery can deliver under specified conditions, which of course affects the price.

The three most common ratings of interest are:

  • CCA – cold cranking amps
  • RC – reserve capacity
  • Ah – ampere hours or amp-hours

These ratings have been defined by the Battery Council International (BCI) to provide a uniform standard.

CCA – Cold Cranking Amps

According to Interstate Battery System International (Marine/RV Battery Maintenance, Publication 200004-CS, May 2009), CCA is defined as the amount of current in amperes that a battery at 0° F (-18° C) can deliver for 30 seconds while maintaining at least 1.2V per cell (that’s 7.2 V for a 12V battery).

This rating applies mostly to starting/lighting/ignition (SLI) batteries and it is a rating of how well the battery will turn over an engine under moderately cold conditions. As the temperature drops, the cranking capacity of the battery is reduced, so the higher the CCA number, the better the battery can be expected to perform in extreme cold.

Similar Ratings: MCA ( Marine Cranking Amps) and HCA (Hot Cranking Amps)

Similarly, other cranking ratings differ only in the temperature specification. In all cases, it is the current delivered for 30 seconds.

Marine Cranking Amps (MCA)

MCA is the amount of discharge current a battery can deliver at 32° F (0° C) under the same criteria as the CCA. The MCA rating may be found on deep-cycle RV/marine batteries. Again, the higher the number, the more power the battery can deliver under the specified conditions.

However, because a battery is more efficient at warmer temperature, the MCA will be higher than the CCA – the Interstate Battery Terms Glossary calls it an “artificially high rating” – and it is important not to confuse the two.

Hot Cranking Amps (HCA)

On the same topic, some batteries may list an HCA (hot cranking amp, sometimes called just cranking amp or CA) rating similar to CCA that defines the current output at 80°F (27°C). Again, this rating will be higher than the CCA and the two ratings must not be confused.

According to Interstate, temperatures above 90°F (35°C) will adversely affect battery life and performance.

RC – Reserve Capacity

Of importance to RV owners: when considering coach batteries, this rating is the number of hours over which the battery can deliver 25 Amps of current (at 80°F / 27°C) without falling below 1.75 Volts per cell. That’s about 88% of its capacity or 10.5V on a 12V battery.

Reserve capacities vary widely, depending on many factors. A general purpose battery may last for only an hour or two at that rate of discharge, while an expensive deep-cycle battery for solar or industrial use may last six or seven. The larger the number, the greater the storage capacity of the battery.

Some manufacturers use a lower discharge rate than 25A. At lower discharge rates, the battery will, of course, last longer. At 5A of current drain, for example, the batteries cited above may last up to 12 hours and 45 hours, respectively. When evaluating a battery, check to see what discharge rate is used in calculating the RC. This information may not be on the battery label but may be available from the dealer or on the manufacturer’s website.

A deep cycle battery is allowed to cycle to about 50% of its capacity (any more will reduce battery life), giving it a greater reserve capacity in reality if not in rating.

Ah – Ampere Hours or Amp-Hours

This is another measure of the storage capacity of a battery. It is the inverse of RC, being the amount of current that a battery can deliver for a specified number of hours without dropping below 1.75V/cell. The BCI standard is for a20-hour discharge at 80°F / 27°C.

A battery that can deliver 5A of current for 20 hours has a 100Ah (5A x 20 hours = 5Ah) rating, while one that can deliver 10A of current has an amp-hour rating of 200Ah. Again, the higher the number, the better the storage capacity of the battery.

The specifications commonly used for a lead-acid automotive battery – CCA, MCA, RC, and Ah – are important and useful information for selecting a battery. While most owners trust that battery department to select and install the proper product, a little background knowledge is always useful.

What is Battery Depth of Discharge?

According to Interstate Battery System International ( “Marine/RV Battery Maintenance”, Publication 200004-CS, 5/2009), the battery depth of discharge (DOD) is a measure of discharge expressed as a percentage of its full capacity. The state of charge is 100% minus the DOD. A battery with a 70% state of charge has a DOD of 30%

This is not a simple comparison of voltage readings. A fully-charged lead-acid battery will read 12.75V (DOD=0%), but a 50% discharge does not mean that the voltage drops to 6.35V. A voltage reading of 11.90V indicates 100% discharge and battery drain should be stopped or the battery may become damaged.

For flooded (filler-cap) batteries, it is possible to determine the state or charge/DOD by measuring the specific gravity of the battery acid using a hydrometer. With maintenance-free batteries, a good digital voltmeter must be used.

What is a Battery Cycle?

A cycle is defined as one battery discharge and subsequent recharge. A cycle can be shallow, moderate, or deep. These are relative terms and may vary between manufacturers. Interstate defines them as follows:

  • Shallow cycle – discharge does not exceed 10% (state of charge does not drop below 90%)
  • Moderate cycle – DOD does not exceed 40% (state of charge 60% or above)
  • Deep cycle – DOD exceeds 40% (state of charge approaches 0%)

Battery Life and Battery Cycles

The life of a lead-acid battery depends on many factors including, but not limited to:

  • Battery maintenance
  • Depth of discharge
  • Battery temperature
  • Proper recharging
  • Cycling use
  • Vibration

The battery service life is inversely proportional to the DOD per cycle. To put it another way, if a battery is discharged repeatedly to 100% DOD (with all other variables kept the same), its cycle life will be less than half that of a battery discharged to only 50% DOD.

“Therefore, to optimize the performance of a marine/RV deep-cycle battery,” advises Interstate, “it is recommended that the consistent discharge level not fall below 50%.” Battery electrical systems should have a low-voltage monitor that cuts appliance operation before the battery reaches a DOD that can seriously harm the battery.

When the battery level indicator light on the service panel shows amber or drops to the next level, take a voltage reading of the battery and check the chart above to determine the DOD. For the most accurate voltage reading, Interstate recommends putting a load of 10-15A on the battery for three minutes, then removing the load and resting the battery for one minute before reading the voltage.

Knowing the depth of discharge and following proper cycling and recharge procedures will help extend the life of a deep-cycle marine/RV battery.

The lifespan of an RV battery is dependent on several factors, and the quality of use. If used and maintained correctly, it can last up to 5-6 years. You also need to ensure that the battery is used completely before recharging.

When you need to replace a battery, you’ll have to remove the negative cable first. However, if you’re reconnecting the battery, you should start with the positive cable after cleaning the connections.

Furthermore, you should also ensure that the battery’s electrolyte level is optimal — neither too low or high. This will prevent the battery from failing prematurely.

What Should You Look For in Your RV Battery?

When you go through the descriptions of RV batteries, you’ll come across a number of details. It’s easy to be overwhelmed by all the information thrown at you, especially if you don’t know how to interpret it.

Starting and deep-cycle batteries are available in similar sizes and with similar performance ratings; it is the intended use that determines which type is best. When the need is for a brief, intense discharge (such as cranking a car starter motor or running a discharge pump), a starting battery is best. For a long, slow and steady discharge (such as running low-amperage appliances, lighting etc.), a deep-cycle battery is the right choice.

As for liquid versus sealed lead-acid batteries, the choice is clear. The reduced maintenance and reduction of the potential for corrosive acid spills make SLA batteries the recommended product where the battery or battery bank is not easily accessible (such as tucked away in a cubbyhole in the RV coach).

Here are some of the key aspects to look for when buying a new battery:

Capacity

The RV battery’s capacity is measured in ampere hours (Ah). This represents the amount of current the battery can deliver over an hour long period. As such, a battery with a higher capacity is better because it can store (and subsequently discharge) more power. However, batteries with higher capacities also tend to be larger in volume. So you should also take space into consideration.

If you need to go off-grid for a while without the potential for a recharge, it’s important to compute how much power you’ll need and get a battery that can accommodate that.

Depth of Discharge

Expressed in percentage form, the depth of discharge represents the amount of power discharged by the battery. In the case of lead-acid batteries, the depth of discharge is related to the battery’s life cycle. It’s important to get a battery with a depth of discharge, which when followed, can maximize your battery’s life cycle.

Voltage

The recommended voltage for RV batteries is 12V DC. You can achieve the same voltage by connecting two 6V batteries. Your RV battery should also be able to accommodate an inverter that can convert the DC to AC.

Medium of Charging

There are different mediums and methods for charging an RV battery. You can use solar panels, a generator, or shore power. The three can be used in combination.

Regardless of the medium, you should also use a smart charger or charge controller. This will ensure that your battery is receiving the correct type and amount of charge.

Resilience to Different Temperatures

You need to choose an RV battery that’s tolerant and can provide power at both low and high temperatures. For example, if you’ll be using the RV battery during hot summer months, your battery needs to be tolerant of high temperatures. If you’ll be using the RV battery during a cold winter, your battery needs to be tolerant of low temperatures as well. In case of low temperatures, choose a battery that can supply power at 0 degrees.

Vibration Tolerance

The construction of the RV battery must be sturdy enough to withstand shocks and vibrations. This is important because the battery will be placed in a moving vehicle and thus will likely experience vibrations frequently.

How to Charge RV Batteries?

RV batteries can be charged in a number of different ways:

With Solar Panels

When placed under direct sunlight, solar panels can produce 100% watt output. However, before charging a battery with the solar panel, you need to determine how long it will take for the 12V battery to be charged completely.

Some solar panels come with LED indicators to let you know if your RV is being charged. Some also come with charge blockers to prevent overcharging. However, in lieu of a charge blocker, you should install a charge controller to prevent overcharging.

With Generators

To charge your RV battery with a generator, you need to charge the generator completely and plug it into an AC outlet. Furthermore, your RV must be parked safely with the emergency brakes engaged.

In order to optimize the charging process, unplug all the electronics and appliances in the RV and connect the generator to a 120V AC outlet. If that is not an option, you can use a portable generator with a 12V C output, but that would be slower.

The amount of time it takes to charge a battery will also depend on the temperature. If it’s below 40 degrees, you might not be able to achieve full capacity of charge.

Next, you need to plug the RV into the generator. The battery should be charged within two hours, although it might take longer if the charge has depleted below 20%. Once the battery has been charged, you should plug your generator and charge it for future use.

Charging on the Move

In order to charge an RV while still driving, you need to access a few tools: Anderson plugs, high-quality high-amp cables, and a voltage controlled relay (VCR).

Prepare the VCR first. It will disengage and parallel the auxiliary, thus closing the relay. As a result, your RV batteries will be paralleled based on the preset level. Once you turn on the RV, the relay will be opened and the voltage will be brought to the preset level.

The high-amp cables and Anderson plugs should be used to combine batteries to mitigate a voltage drop. Make sure that the cables can be easily detached at the tow bar.

To negate the possibility of a fire hazard, use the circuit protection that comes as a 50-amp auto reset circuit breaker. Insulation can be provided in the form of rubber boots slipped into the breakers. This process will ensure that your RV batteries are charged, even while you’re driving.

Is it Important to Install an RV Battery Monitor?

Installing an RV battery monitor is not a necessity. However, it can prove to be a great investment.

A battery monitor shows you the battery’s charge state, usage time, voltage level, historical data, etc. While charging, you can see how much current is being put into the battery. You can also monitor the rate of discharge to make sure the battery doesn’t go beyond the depth of discharge rate.

These details — when monitored closely — will help you keep track of your battery and ensure it’s working in optimal condition.

What is an RV Battery Disconnect Switch and How to Install It?

An RV battery disconnect switch is located either on the battery compartment or the inner control panel. It helps to cut the current flow from the negative cable, so nothing can draw power from the battery.

The installation of a battery disconnect switch is pretty simple. You have to run the negative cable of the battery from the RV to the one on the switch’s side. You also have to run a shorter cable from the switch to the battery. The battery can then be disconnected by simply turning the switch.

Conclusion

Portable batteries are the beating heart of a recreational vehicle. As such, you should choose your RV batteries wisely, armed with vital information. My aim has been to arm you with all the information you need to select the best RV battery for your specific needs.

Now go ahead and give that RV a go!