There used to be a time when AGM batteries were considered the best option for your RV. And at that time, it was true because the alternative, sealed lead-acid, had several issues such as acid spills or low shelf life. However, with the arrival of lithium batteries, more and more RV owners are switching to newer technology.
An RV is more than just a means of transportation. Many campers use it as their home away from home and install kitchen, heaters, and air conditioner units inside it. Naturally, you need to install a powerful battery if you want to use all the appliances to their fullest extent.
That is what brings us to this comparison between AGM vs. lithium batteries. Which one is better? Which one will last longer? And most importantly, which one should you buy if you are planning to upgrade the battery in your RV?
These are the questions that we will try to answer in this article by giving you a detailed comparison between AGM and lithium battery technologies. So, without further ado, let us get started.
What Is An AGM Battery For RV?
AGM battery is a form of sealed lead-acid battery. The term AGM stands for Absorbed Glass Mats. Invented back in the seventies, this type of battery is the most common choice when it comes to use in your RV.
In this type of battery, there are fiberglass mats inside that absorb the liquid electrolyte. That is what makes them truly spill proof, unlike flooded lead-acid batteries.
The major advantage of this type of battery over the traditional flooded lead-acid ones is that they give you up to five times the charge rate, allow you to deep-cycle, and have a very low self-discharge rate. In addition, AGM batteries typically do not have sulfation issues.
What Is A Lithium Battery For RV?
Compared to AGM batteries, the lithium ion battery is a relatively new invention in the world of RV. And some might argue that it offers much better performance than any lead-acid type battery. We, however, will leave that for you to decide.
In lithium batteries, lithium ions move between the anode and cathode that is submerged in a lithium salt solution. The size of the battery can be different sizes and shapes and can also feature different chemistries. Typically, the lithium iron phosphate battery chemistry is considered the safest and most stable one.
Other lithium chemistries include lithium cobalt oxide, lithium nickel manganese cobalt oxide, etc. The best thing about this type of battery is that they have an extremely slow discharge rate and are extremely lightweight. These batteries also come with an internal BMS to keep them safe and functional.
|Lithium Battery||AGM Battery|
|Cost Of Ownership||More Expensive||Less expensive|
|Lifespan||Lasts Longer||Doesn’t Last Very Long|
|Availability||Less Common||More Common|
|Maintenance||Maintenance-Free Design||Needs Maintenance|
|Performance In The Cold||Not Suited For Cold Environments||Handles The Weather Better|
|Price||Check Price||Check Price|
AGM Vs. Lithium RV Batteries
Now that you have a basic idea about AGM and lithium batteries, we can dive into some head-to-head comparisons between the two. There are strengths and weaknesses to both battery types, and after going through our comparison, you can decide for yourself which one is more suited to your requirements.
Both AGM and lithium batteries are pretty durable compared to older technologies like flooded lead-acid batteries. But if compared against each other, the lifespan of a lithium battery is much greater than that of an AGM battery. With lithium-ion batteries, you can expect at least ten times the lifespan of an AGM battery.
In most cases, AGM batteries are capable of 400 to 1000 cycles depending on their quality. But a lithium battery offers a charge cycle of 5000 to 10000. Needless to say, the longevity of an AGM battery, though pretty good, is no match for lithium-ion batteries.
2. Weight and Size
Weight and size are two other fields where lithium batteries take the cake. Since lithium batteries do not contain any heavy lead acids in the chemistry, they tend to be about one-third the weight of a typical AGM battery. Not only that, but they also can come in a much more compact design.
For RV owners, the lightweight design of a lithium battery is always a welcome thing. Since the AGM battery is heavier, it can weigh down the camper. And since lithium batteries also have a higher energy density, you can also get more power out of them compared to AGM batteries.
Lithium batteries are expensive; that much is a given. When comparing AGM vs. lithium-ion batteries, the price of lithium batteries will always trump that of even a high-quality AGM battery. But before you jump ship, consider the long-term cost of maintenance and replacements.
While lithium batteries may cost more upfront, their lifespan, charge capacity, and maintenance-free design make them extremely valuable. Even though you can find a decent AGM battery at a lower price, you might not be saving a lot of money in the long run as it will require some maintenance from time to time.
4. Depth of Discharge
Depth of Discharge, or DOD for short, is a bit complicated to understand for those not familiar with battery technologies. In layman’s terms, DPD refers to the percentage of a battery you can drain before having to recharge it. For example, you can go as low as 50 percent with lead-acid batteries.
However, if the charge of a lead-acid battery goes below 50 before you recharge it, it will have a significantly reduced lifespan. With 80 to 100 percent DOD of lithium-ion batteries, this is not an issue at all. You can fully drain your lithium battery before recharging it without having to worry about battery damage.
This matters because, in a practical scenario, you are only getting about fifty percent of the capacity of your lead-acid battery. Going below that fifty percent mark means damaging your battery in the long term, which is never ideal when buying a new RV battery.
The best thing about lithium batteries is they feature a truly maintenance-free design. In addition, most of the lithium batteries in the market come with an internal Battery Management System, or BMS, to self-diagnose and repair any issues that may come up in the chemistry.
Even though they require less maintenance than flooded lead-acid options, AGM batteries are just not on the same level as lithium-ion batteries. So, you will need to give some attention to this type of battery and maintain it from time to time which can naturally be a hassle for some people.
6. Performance Stability
AGM batteries have been on the market for a long time and are still being made so they can evolve as needed to perform better. On the other hand, Lithium batteries are getting more advanced and they’re becoming cheaper.
This means that you could save a lot of money with the help of these parts in the next generation. For now, it’s better to stick with AGMs since they have a low, upfront cost. Keep in mind that you will need to maintain them to ensure they last long.
Is A Lithium Battery Better Than An AGM Battery?
Lithium-ion batteries have some obvious advantages over AGM batteries. With lithium batteries, you can expect a better lifespan, better DOD, better charge capacity, and it also requires no maintenance. In fact, this type of battery is also much lighter and smaller than AGM batteries.
However, lithium batteries have a significantly higher upfront cost compared to AGM batteries. So, if you are on a tight budget, going with a lithium battery might not be the best decision. AGM batteries can still give you decent performance for the price.
Can I Replace My AGM Battery With A Lithium Battery?
Yes, of course. If you want to upgrade to a lithium battery, you can easily replace the old AGM battery in your RV. However, since lithium batteries are expensive, you have to be prepared with a decent budget. Also, make sure that the lithium battery that you are buying is powerful enough to meet your RV’s requirements.
Is AGM Battery Worth The Extra Money?
Well, AGM batteries are quite a bit cheaper compared to lithium batteries. But if you have to decide between AGM and flooded lead-acid batteries, it is often worth spending the extra couple of bucks on getting the AGM battery. AGM batteries require significantly less maintenance and deliver better power compared to their sealed lead-acid counterpart.
Can I Charge A Lithium Battery With An AGM Charger?
Typically, you only want to charge lithium batteries with lithium chargers. But if you absolutely had to, you could use a lead-acid charger to recharge your lithium batteries. Before trying it, however, make sure the settings in the charger are set to AGM, which uses a charging voltage ranging from 14.1 to 14.4 volts.
As you can see, lithium batteries are often considered the superior choice when it comes to RV use. They often have a better lifespan and give you more power per dollar spent. And since lithium batteries are smaller and lighter, your overall RV weight would be kept minimal if you use lithium batteries inside it.
However, AGM batteries can also be a great pick-up, especially if your budget is low. Though you might need to maintain it from time to time, if you are familiar with battery technologies, this should not be an issue for you. We hope our complete comparison of AGM vs Lithium-ion batteries could help you find the right pick for your RV.