Most people don’t know a thing when it comes to batteries, and that is, to me, a shortcoming. Even if you use electricity from the grid all the time, it is still advantageous to understand a thing or two about batteries. You might think, why do we have to use batteries at all? When the lights suddenly go out for a long time, when you want to take your RV outside for an excursion off-grid, batteries will come in handy.
If you have or are planning to install a solar system, then you will have a means to store the produced energy. This is extremely useful since you don’t really use up all the produced energy all the time, which can be wasteful. They give you flexibility with electricity energy. They are portable, versatile, and most are reliable.
By far some of the most reliable batteries I’ve ever seen actually come from the AGM battery family. I will go as far as to say AGM batteries in general give you the best bang for your buck (or, close to that). Though this doesn’t necessarily mean that they beat out lithium-ion RV batteries at the same price range, they have their obvious advantages. In this article you will learn more about these AGM batteries. Then we will discuss some of the best AGM batteries you can find on the market right now.
Contents
The Basics About AGM Batteries
What is an AGM battery?
Nowadays, it is common sense for vehicles to use rechargeable batteries. Among these rechargeable battery types, there exists one called lead acid battery.
This type of battery is then further divided into more subtypes of batteries, the most prominent ones include AGM and flooded cell batteries.
An AGM battery (short for absorbed glass mat battery) is a type of battery that incorporates electrolytes inside of the battery, the same way flooded cell batteries are made. AGM batteries became widely known around the 1980s.
You can find application of this AGM type battery in a lot of vehicles, not just RVs: bikes, aircrafts, submarines and other military purposes. If you want one for your car, then there are AGMs that are specifically made for them as well.
How does an AGM battery work?
An AGM battery is a type of lead-acid battery, which means that it relies on a chemical reaction in order to charge and discharge electricity. Just like its name suggests, in the charged state, the electrodes include lead and lead oxide, with the electrolyte being sulfuric acid; while in the discharged state, both the electrodes become lead sulfate, while the electrolyte is now water (just another chemical reaction no one care about).
This chemical reaction is at the core of the charge and discharge mechanism, but AGM batteries are also differently constructed compared to flooded cell batteries. AGM batteries contain a glass mat separator which is ultra-fine, saturated with battery acid, and then packed tightly between the plates, and they are welded firmly so as to become immune to vibrations and shocks.
Advantages & disadvantages of AGM batteries?
In the 1980s, the AGM batteries were introduced to military vehicles and proved to be reliable, lightweight, and powerful enough for military aircrafts at the time. It wasn’t easily damaged either. It can withstand low temperatures, even at freezing temperatures, the AGM batteries come out unscathed although it won’t be able to function.
The depth of discharge for these batteries are rather low, so you are prompted to take care not to over or under charge them (from 50 to 100% capacity is best for battery life and reliable performance). There are of course many deep cycle AGM batteries on the market, but some don’t actually live up to that title.
Among lead-acid batteries, an AGM battery has a clear advantage compared to some other batteries, including the flooded cell batteries. Despite its obvious disadvantage in terms of price range, it is almost maintenance-free, and during action, it can give your vehicle powerful bursts of starting amps as well as maintain charge and run electronics for a longer period of time. The comparison between AGM batteries and flood cell batteries is akin to the one with diesel and petrol.
If you compare AGM or other lead-acid batteries to the more recent lithium ion batteries however, the lithium ions turns out to be the victor in terms of reliability, efficiency and overall performance. It beats out the lead-acid in almost every category by miles, save for cost: capacity, depth of discharge, lifespan.
After all, you get what you pay for. AGM batteries aren’t the absolute best in the battery industry, it beats out some and is bested by some, but most people think of them as some of the most reliable batteries in history.
5 Best AGM Batteries for RV
1. Weize 12V 100AH Deep Cycle AGM
Specifications:
- Brand: WEIZE
- Vehicle service type: Van, Scooter, trailer
- Size: 12V 100AH
- Voltage: 12 volts
- Battery cell composition: sealed lead acid
- Dimensions (LxWxH): 12.99 x 6.73 x 8.34 inches
- Number of cells: 6
- Item weight: 60 pounds
- Voltage: 12 volts
- Terminal: marine terminal
Why we love it:
This battery is certainly a state-of-the-art creation. There are many great features that we would like to disclose about it. Besides of course the wonderful technology that is AGM, this product is also built with ABS container material, so the chances of vibration and collision damage is further reduced. On the outside, the two terminal bolts are easily recognizable and is marked with positive and negative symbols, so you can’t go wrong with wiring.
One of the things I love the most about this battery is its overall look that just spells quality, simplicity and professionalism. Coincidentally, the user reviews and user ratings indicate the same thing. People think of the Weize 12V 100Ah as a great bang for their bucks, it is durable, it is easy to install, the chances of an acid spill is slim to none.
There are a lot of ways in which this AGM battery can be utilized. Of course, this is one of the best AGM batteries for RVs, however, you can get it wired to your home solar power system and enjoy the generous supply of electricity in your home. It has a relatively low discharge rate at about 40% per year, but it is recommended that you charge it up once every 2 or 3 months even if you don’t plan to use it yet/anymore.
This is the best way to preserve the battery as well as prolong its shelf life. If you love going by boats, then this is also a decent battery to either power your boat, or be a substitute power generator. The possibilities are endless. On your RV, it can probably power every kind of electronics you need in case the grid is failing, even air conditioners. Weize, in my opinion, has done a very good job with this product. This is evidenced by the agm battery rating on Amazon.
Pros:
- ABS container: prevents vibration and collision damage, increases durability
- Thick plates: prevents extensive electrical discharge, increases battery standby time and reduces plate corrosion speed.
- Unique vent valve design: controls water loss speed
Cons:
- This battery is pretty heavy for an AGM battery
- Guidance information on charging and use is limited
- The products once bought cannot be returned in any way, so be extremely well-informed before buying them
2. Universal Power Group 12V 100Ah Solar Wind AGM
Specifications:
- Brand: Universal Power Group
- Recommended uses: Marine, Solar, RV, Trolling, Camping
- Size: 12V 100AH
- Voltage: 12 volts
- Battery cell composition: sealed lead acid, AGM
- Dimensions (LxWxH): 12.17 x 6.61 x 9.16 inches
- Item weight: 60 pounds
- Voltage: 12 volts
Why we love it:
There are many things to love about this battery. Aside from the fact that the AGM technology makes the product much less susceptible to damage than other batteries, this battery has a unique feature that stands out. Many people have commented that the battery holds up really well over the years.
This battery, in terms of looks, is almost identical to the one above, yet is much cheaper. It can be used almost anywhere, whether it be a solar system, on an RV, or during a camping trip. AGM SLA technology helps protect the battery from spilling, damage, etc. This battery apparently also has a high discharge rate, which normally means you can charge them quickly. Aside from fast charging, a high discharge rate battery has better temperature stability and tolerance than regular discharge batteries. Also, this battery can easily recover from a deep discharge cycle.
With these features on hand, the battery is shock resistant, vibration resistant, can be mounted in any positions, and can handle high and low temperatures while maintaining performance. With the capacity of 100Ah, you can power a whole house for a long time. As you can see, this battery comes with a lot of benefits. It is one of the best RV AGM batteries that we have found. You can definitely go off-grid on your RV and depending on your consumption, 2 or 3 of these batteries should have enough power for 3 days. After reviewing some of the agm battery reviews out there, I think this battery sits at the right price for what it’s worth.
Pros:
- Lasts a long time, high durability
- Has 100Ah maximum, so running even an AC is no problem
- Very good customer service (based on customer reviews)
Cons:
- Some faulty products might leak very subtly, so you have to constantly make sure the products are working normally. Leakage is dangerous, not just to you and your family, but also to electronic devices that these chemicals come in contact with.
- Although the battery is allegedly deep-cycle, you shouldn’t drain the battery to lower than 50% daily. You can still deep discharge, but don’t abuse it.
3. ML35-12 – 12V 35AH U1 Deep Cycle AGM Solar Battery
Specifications:
- Brand: Mighty Max Battery
- Vehicle service type: Van, Scooter, trailer
- Amp hours: 35Ah
- Voltage: 12 volts
- Battery cell composition: lead-acid, AGM
- Dimensions (LxWxH): 9 x 9 x 6.2 inches
- Number of cells: 6
- Item weight: 24 pounds
- Voltage: 12 volts
Why we love it:
This one is from the Mighty Max Battery brand. The company has claimed their brand to be “a name you can trust”. And we sure did. This battery comes with services ranging from 33 to 36Ah, so it is possible to choose one according to your needs. The AGM technology ensures the quality as well as the durability of the product. It is also a sealed lead acid battery, so you can be assured that the liquids inside are non spillable. As a matter of fact, this battery can be installed in any kind of awkward position that is convenient to you. However, installing it upside down is totally unwelcome, since there is probably no good reason to. You can effectively use this to power your motorcycles, alarm systems, solar systems, backup systems, generators, whichever you see fit.
You will need a charger that is adaptable to it though. Many users have remarked that the battery is not heavy or too light, so you can easily move it around in your home/vehicle. Also, one of the things that make this battery stand out the most happens to be the most important aspect of a high quality battery: the charge retention. This battery will retain the charge for a long time, in addition to being a deep cycle battery. You can charge once and power a whole lot of electronics.
Pros:
- The shell is hard, crafted from the finest materials. Coupled with the AGM SLA technology, the battery is foolproof in terms of durability. It is portable, has the perfect size and weight, so you can relocate it anywhere easily.
- The customer service is very nice and helpful
- Cheap and plentiful power storage
Cons:
- It needs a lot of time to charge, the period can go up to 12 hours.
- The products aren’t guaranteed to be a good one, you might need to review the shipped products and return them if problems arise.
4. XS Power D3400 XS Series 12V 3,300 Amp AGM High Output Battery
Specifications:
- Brand: XS Power
- Vehicle service type: Passenger car, boat
- Voltage: 12 volts
- Battery cell composition: lead-acid, AGM
- Number of cells: 6
- Item weight: 21.8 pounds
- Terminal: M6 terminal
- Wattage: 4000
Why we love it:
This product is highly recommended on Amazon. Even though the brand itself isn’t very widely known, outside of the niche market that they primarily provide for, this battery in particular is fitting for a variety of needs. It is a high performance battery that works best in high performance cars. For only $100, you are guaranteed to power most of your car’s needs. For your everyday electronics, this product will work just as well. However, this product works best in a vehicle like your household RV or caravan. Some customers even went as far as to say this is the best battery that they have ever had.
There is still a lot more to desire about this little battery. For example, this battery is deep cycle, you can discharge it to as low as 20% the capacity. Even more impressive is the power output produced. With a battery as powerful as this, you can kickstart your RV without a hitch. This is something you don’t get even from a lithium ion battery (most of them, of course), and for a price that you can’t turn down.
Like many products on this list, this item comes with added parts for M6 terminals. The charge capacity is 65Ah, which is not the highest, but considering the power output, this product from XS Power is ideal for race cars. This is easily one of the best deep cycle AGM batteries on the market right now.
Pros:
- This battery is a total beast
- You can easily set this up before use
- The shipping comes very quickly and on time.
- It is pretty cheap.
Cons:
- Some say that the battery life doesn’t hold up very well
5. Vmaxtanks VMAXSLR125 AGM 12V 125Ah SLA Rechargeable Deep Cycle Battery
Specifications:
- Brand: Vmax Solar
- Vehicle service type: Van, Scooter, trailer
- Size: 12V 125AH
- Voltage: 12 volts
- Battery cell composition: sealed lead acid, AGM
- Dimensions (LxWxH): 6.8 x 12.9 x 8.7 inches
- Number of cells: 6
- Item weight: 75 pounds
- Wattage: 1700
Why we love it:
Vmax Solar has the highest capacity out of the ones we review today. Also, it happens to be the most expensive, I think (there may be a discount when you buy it).
This product is definitely worth every penny. AGM is again the core technology, but now the plates are military grade, so durability is increased.
It is advertised to have a 99% recombination rate, so users are perfectly safe from dangerous leakage of gasses and fumes, and it is vibration resistant.
You can mount it in any direction you want, and can be used either outdoors or indoors. Another thing I love about it is the Maximum charge delivery system. This will give you a relatively fast recharge rate and since it is a deep cycle AGM battery, draining the charge to under 50% is totally fine.
If 125Ah is not enough for your family’s usage, then I would recommend checking out the other products in the SLR series, which range from SLR 60 to SLR 200. If you are going to use these batteries for camping trips or RV off-grid excursions, then two of these 125Ah batteries are plenty.
Many customers rated the batteries highly for their long lasting endurance, and said that they would buy these again when they decide to replace their old ones.
Pros:
- The batteries are really durable, and can last a long time while losing only a little bit of charge after a while.
- Fast shipping
- You can get a discount for each battery by buying more than 1 battery. The battery itself is reasonably priced.
Cons:
- Heavy
- You will need to follow the charging recommendations provided by the manufacturers, or else the battery won’t hold up very long.
How To Choose The Best AGM Batteries: Buying Guide
There are several things to consider when trying to choose the best RV AGM batteries. For example, voltage. The voltage output is important because you want to have an RV battery that is compatible with whatever you are using it for. As you can see, all of the AGM batteries, including the ones listed above, has a 12-volt output.
Next, you can have a look at the capacity on these batteries. You don’t want to have a battery that runs out too quickly for obvious reasons. There are batteries that range from 45 Ah to even as high as 125Ah, so pick a number. If you aim for heavy-duty usage, then 125Ah is your best bet.
Another thing that people generally overlook is the cold amp rating. A cold amp rating indicates the maximum amps that your battery can provide in a cold weather. There are batteries with ratings of up to 500Amps and even 1000amps, and as you can probably tell, the higher the better.
Not all AGM batteries are the same, although they aren’t much different from one another in terms of core technology. Even so, there are certain times when internal designs differ that makes all the difference when it comes to battery quality. Primarily, we are looking at lead acid batteries and sealed lead acid batteries. As we have gone over this before, sealed lead acid’s only advantage is that it is spill-proof. That alone takes care of most of the safety issues that can happen in the future.
Next up is the price. Batteries that cost around $50 and $150 aren’t that good, but they are sufficient when it comes to charging somewhat regular appliances. If you have money to spare, I would recommend the ones that are from $150 and above, as they are generally the more reliable type of batteries.
Finally, you have to look at the customer reviews. You have to make sure that you are reading the authentic reviews and checking out AGM battery ratings from actual users of the products and not trolls or PR reviews that aren’t reflective of the product quality at all. Not only do you need to see the product’s actual quality, but also the company’s competence in customer service. Many companies can scam you. Look for a reputable company which offers reliable warranty. AGM batteries can live long, but 1- or 2-year warranties are of great help, especially when sudden incidents occur with your battery.
How to Take Care of an AGM Battery?
Batteries aren’t fragile, but despite the initial performance, some won’t hold up for only a few months of usage.
Don’t put them too high up
AGM batteries are durable on the outside, but still you don’t want to put them too high up or be too careless as to drop them too many times, just to be sure. Even sealed lead acid batteries can get unsealed when getting dropped a certain number of times. Chemical leaks are devastating for you and your family, as well as your appliances.
Recharge your batteries once every 3 or 4 months if you are storing them.
This is crucial. Sometimes people store batteries due to lack of use. However, when you leave them out of service for too long, these batteries might become out of service for good. Charging a battery to full charge when not in use for 3 or 4 months is a must, before the sulfation process takes place (due to deprivation of a full charge). Another thing anyone should keep in mind is to store these batteries in cool and dry places under good ventilation.
Prevent sulfation
Sulfation gets in the way of converting chemical energy to electrical energy, so you don’t want to let sulfation occur too often. A de-sulfation device is also a recommended remedy for this phenomenon. If it is already too late, then a reverse pulse desulfation charger, which is a mode that comes with some of the chargers on the market. This mode will reduce the effects done by the sulfation reaction, to get your battery working again.
Charging your battery
This sounds simple enough, but there are still precautions when it comes to handling a battery. I know deep cycle batteries claim to be able to drop in charge level down to 20%, but it is a general rule of thumb that you don’t leave the battery discharge to under 50%. This is good practice, but don’t take it from me, you can have a little experiment to see for yourself.
Also, overcharging can damage your batteries internally, while undercharging can shorten their lifespan. You will need to find the perfect charger that fits your battery.
FAQs About AGM Batteries
There are tons of things that you wish you knew before buying anything right? Electronics are especially tricky.
If you feel like you still need more answers before buying an AGM battery product, then we have some FAQs that we have answered below.
Take a look, you might pick up a thing or two. I hope that this will clear some things up.
1. Is an AGM battery worth the extra money?
Yes, you will find the AGM battery to be a much more perspicacious choice than, say, a flooded-cell battery. You are only paying a little bit of a higher rate, however, the benefits are substantial.
After buying once, you won’t need to pay any extra maintenance fee in the future. That is a big plus. Not limited to that, as we’ve mentioned before, the electricity generated by these AGM batteries is very reliable, and it continues to function properly in low temperatures without inflicting internal damage on itself.
One of the most notable properties of AGM batteries is that it is much safer to use than other batteries, thanks to its usage of glass mats. Also, some AGM batteries are deep cycle batteries, which means you can effectively use it for a longer period of time before having to charge again. What is there not to like about such a battery?
2. Do AGM batteries last longer than regular batteries?
Depending on whatever kind of batteries you consider regular, the answer might vary. If you used flooded cell batteries in the past, then you will be surprised by the difference between the lifespan of the two. AGM batteries last much longer than their flooded counterparts.
Although markedly tough and having a long lifespan, lithium-ion batteries have always been on another level compared to AGM batteries.
Regarding longer-term installations (for example a solar system on the roof), lithium ion batteries are the way to go.
However, if cost is the deciding factor, then you can settle for AGM or gel batteries just fine, but they will give in a long time before lithium ion batteries do. For now, in a test of endurance, lithium ions seem to be taking the lead, but in the future, there will be lots of innovative alternatives waiting to take over.
3. Are AGM batteries better in cold weather?
No batteries can expect to face extreme cold weather conditions and get out unscathed, not even lithium ion batteries. Not only will your AGM batteries perform worse, but the lifespan of the batteries will be reduced when exposed to temperatures below 32 degrees Fahrenheit.
However, as we have looked into it before, AGM batteries seem to get away with it to a certain extent. Since the electrolytes are stored inside glass mats, they won’t expand the way “flooded” cell batteries do, so the two electrode mats aren’t damaged at all. During the cold weather conditions, the capacity of AGMs fall around 70-80% of its rated capacity. Also, due to the fact that batteries discharge more quickly in these types of weather, you may need to charge it again very soon.
The most important thing for those using AGM batteries to keep in mind as the rule of thumb is that you must not charge the battery in sub-32 Fahrenheit weather conditions (0 degrees Celsius) or when the temperature is above 104 Fahrenheit (40 degrees Celsius). This will prevent the battery from overheating and retaining permanent damage. So the end note is that AGM batteries, like any other batteries, are adversely affected by cold weather.
4. Can I trickle charge an AGM battery?
You might already know what it means to trickle charge. But if this is the first time you see this term, then “trickle charge” means to charge a fully charged battery. This doesn’t mean to overcharge it, but rather to charge at the rate at which the battery is discharging, as if you are constantly filling in the blanks.
This way, the battery remains at its fully-charged state. Trickle charge is suitable for almost any kind of battery, and AGM batteries aren’t exceptions. As a matter of fact, although GEL, AGM and Calcium batteries have better lifespan than other kinds of lead-acid batteries, keeping these batteries in almost fully-charged state is widely considered good practice.
This will extend their lifespan. However, be careful since trickle charging for too long will cause the battery to heat up, and in extreme cases might even cause the electrolytes to boil, leading to a potential disaster. Trickle charging is “tricky”.
5. Do I need a special charger to charge an AGM battery?
There is no special charger needed for charging an AGM battery, however, you can buy smart AGM chargers designed exclusively for AGM batteries. If you have yet to buy one or aren’t interested in buying a smart AGM charger, there are several precautions that go with charging your AGM battery.
If you have read somewhere that lower amps work best for lead-acid batteries, they are correct. Very high heat is always an indication that something is wrong. Higher amperes can charge quickly, but this kind of current generates lots of heat, so charging at around 1-10 amps is the best bet unless lifespan reduction of the battery is acceptable to you. Keep in mind that this is only the recommended figure, so charging at amp levels above 10 is safe under normal circumstances.
The worst news for those who don’t want to spend money: Newer batteries work better with newer chargers. 12-volt chargers can only get the charge level up to around 80% maximum. Newer chargers have different modes for different battery types, if you have one, just make sure you choose the correct mode. Also, sulfation becomes an issue when it comes to maintaining performance. There are numerous charger brands that offer de-sulfation modes on their products, you can look into that