If you own a vehicle or motorized boat, ATV, or other transportation devices then you probably know the importance of having a battery charger. If the battery is dead or low on power then the equipment will not be ready for you to use when you are ready to use it.
An AGM battery is made with a specialized glass material that is positioned so that it moves the electrolytes the battery requires between the plates of the battery. These batteries contain very little liquid and in case of an accident that causes a crack or breaks the housing of the battery case there will be no battery acid leaking from the unit. These batteries are often referred to as ‘gel’ batteries. They are frequently placed on vehicles by the manufacturer because of their enhanced safety to the user and the environment.
It is possible for you to charge the AGM batteries with a traditional battery charger, but the best AGM battery charger is one designed to give the battery a slow charge rather than a quick power boost.
- How We Built This List
- Best AGM Battery Charger Reviews
- BatteryMinder 128CEC1: 12V 2/4/8 AMP Battery Charger
- Shumacher SC-1200A-CA – Best Marine AGM Battery Charger
- Optima Digital 1200 12V Performance Battery Charger and Maintainer
- NOCO Genius G7200 12V/24V 7.2A UltraSafe Smart Battery Charger
- Battery Tender 022-0148-DL-WH 12-Volt-4 Bank Battery Management System
- Battery Tender 021-0123 Battery Tender Junior 12V, o.75A Battery Charger
- How to Pick the Right AGM Battery Charger
- AGM Battery Technology
- How AGM Battery Chargers are Different from Other Battery Chargers
- Charging the AGM Battery
- Final Note
How We Built This List
In order to device a list of the best AGM battery chargers we asked vehicle technicians who are trained professionals to try out the chargers and see which ones functioned at the highest level. We asked our experts to rate the chargers based on their ease of use, their safety features, their performance, and their price.
We also had inexperienced individuals use the battery chargers following the instructions provided by the manufacturer. We wanted to know if the majority of people would be able to use the charger with no difficulties. We asked our inexperienced testers to rate the chargers on how easy it was for them to understand the directions in the user manual, and how easy the charger actually was to connect and use.
The following six chargers were the top picks.
Best AGM Battery Charger Reviews
BatteryMinder 128CEC1: 12V 2/4/8 AMP Battery Charger
One of the problems with batteries is they can develop a sulfate residual build-up over time and that build-up will weaken them and shorten the life span of the battery. We were very impressed with the BatteryMinder 128CEC1 because of the technology it has designed into it that helps the charging unit recognize sulfate residue so that it can remove build-up and increase the strength of the battery. The charger does this using a patented high frequency range and this feature can increase your battery life by as much as four times the amount it had before the charger was used on it.
This device is easy to use, and the operating manual was clear and concise. Our experts also loved that you can charge, or maintain a charge on as many as eight batteries at one time when you connect them up using the proper Y connectors in a parallel manner.
This charger is perfect for connecting your boat batteries, lawn equipment batteries, ATV batteries, and RV batteries to keep them hot and ready to use through the cold winter months.
This charger is FCC certified meaning it meets all of the efficiency and safety standards put in place by the California Energy Commission. It also meets all of the safety and efficiency guidelines established by the U.S. Environmental Protection Agency.
Shumacher SC-1200A-CA – Best Marine AGM Battery Charger
Batteries are not all the same voltage, and you need to know that voltage so that you can purchase a charger that will provide the perfect voltage for your batteries. On the Shumacher SC-1200A-CA the device is capable of discerning what voltage the battery you have connected is so that it automatically provides the perfect charge for your six volt or twelve volt batteries.
This charger has a speed charge setting that you can use when you need a battery energized in the shortest amount of time possible. It also has a float mode that allows you to provide a maintenance charge to batteries that are on vehicles that are not used frequently. The float mode helps you to maintain the perfect charge on your batteries without damaging your batteries.
Reverse polarity connections can be devastating to your equipment, but not with this charging system. The charger has reverse polarity protection and has an LED indicator to alert you of a reversed polarity hook-up.
This battery charger is rated as one of the best because it is very easy to use and it protects the investment you have in your batteries. The unit can detect the amount of charging a battery requires and will automatically adjust itself so that it charges the battery and maintains the battery. This feature will increase the longevity of your batteries.
Optima Digital 1200 12V Performance Battery Charger and Maintainer
The Optima Digital 1200 12V Performance battery charger and maintainer can charge a wider range of batteries than most battery chargers. This charger will charge batteries as small as a 1.25 volt. It also has USB charging ports that will allow you to charge many of your electronic devices like your smart-phones, tablets, and other internet connective electronics.
It provides twice the output that other chargers provide so it charges your batteries quicker than most other battery chargers. It can also provide a charge to many 12V batteries that other charges simply cannot provide a charge to.
This battery charges does not simply charge your batteries, it helps to return your batteries to peak performance condition, and it can maintain your batteries that spend a great deal of time not being used.
The alligator clamps that you connect to your battery posts have nonslip grips so you are sure to make a good connection without any mishaps. It also has a work light that helps you connect the unit in dim lighting situations. The work light is an LED so it produces a bright light that illuminates the area you are working in.
The battery charging gauge on the front of the charger will tell you how much of a charge your battery has. This gauge is LED backlit so you can read it even if you are working in the dark.
The selections on the front of the device are easy to understand and you can switch from one setting to another easily.
NOCO Genius G7200 12V/24V 7.2A UltraSafe Smart Battery Charger
The NOCO Genius G7200 is designed to provide the perfect charge to lead-acid batteries but provides a slow enough charge that it is not damaging to AGM or gel batteries. You can charge or maintain your car and truck batteries, your snowmobile batteries, the batteries on your personal watercraft or your lawn equipment using this one battery charging unit.
This battery charger comes with safety features that help to prevent a spark from occurring when the charger is connected to a battery. It also provides reverse polarity protection which further eliminates the possibility of sparking during use.
This small device will provide a charge to a depleted battery, it will maintain a charge on a battery so that it does not become depleted, and it will assess the health of the battery and make adjustments in the way it charges the battery so it can help remove sulfate build-up and improve the condition of the battery.
This battery charger weighs about three and one half pounds so it is light enough for the majority of people to carry or maneuver. It does require one Lithium Metal Battery to operate it, but that Lithium Metal Battery is included in the purchase package, along with a user guide, eyelet terminals and battery clamps. It also has a five year limited warranty provided by the manufacturer.
Battery Tender 022-0148-DL-WH 12-Volt-4 Bank Battery Management System
The Battery Tender 022-0148-DL-WH has four independent charging stations so you can charge multiple batteries at the same time, and maintain multiple batteries that are in different stages of discharge. It can provide 12v charges to four batteries simultaneously.
This unit is easy to operate and it is rated as being ideal for AGM or gel batteries.
This charger has the spark proof safety features that we all love, and it also provides the reverse polarity protection. It is too easy to make a mistake and connect the negative to the positive terminals when you are connecting a battery, but this unit will not allow power to be forced into a battery that is connected improperly.
In order to make sure that your battery is receiving the precise voltage that it requires this charger has a microprocessor that controls the charge being emitted and it takes the temperature into consideration because in colder weather the charge would need to be increased while in hotter temperatures the amount of voltage applied would be lessened. This feature will increase the longevity of your batteries and ensure that you get the maximum use out of each battery you charge.
This device weighs less than three pounds so it can easily be moved around by the majority of people, or easily packed to take along with you when you travel.
Battery Tender 021-0123 Battery Tender Junior 12V, o.75A Battery Charger
Do not let the junior in the name of this battery charger fool you into thinking that it does not have the power to do the work you need it to do. It is ideally suited for charging 12 volt batteries including the lead-acid varieties, the flooded or sealed batteries, and the AGM or gel batteries.
This battery charger is capable of doing the initial charging to restore a dead battery, then switching over to provide a slower power charge, and when it senses that the battery is at charging capacity it can switch to float charge so you do not have to worry about over-charging or damaging the batteries you have connected to it.
The LED light will allow you to glance at the charging unit and know immediately what stage of charging your battery is in. The lights blink different colors to indicate different charging status and there is a convenient legend on the side of the unit that shows what each blinking color indicates.
The safety features include spark proof technology that keeps you safe during connections and reverse polarity protection. All of these features are packed into a charging unit that weighs less than two pounds and is only eight inches wide by nine inches long and only four inches thick.
How to Pick the Right AGM Battery Charger
Choosing the right AGM battery charger will require you to assess your battery charging needs, and the features provided on the charging units you are looking at. You have to determine your priorities so you can choose which features are truly going to be beneficial to you.
Remember that the AGM battery needs the charge it receives to be slow and steady more than fast. This is important to keep in mind when shopping for a charger.
Common Features to Compare
- Reverse polarity protection means you cannot connect the negative battery terminal to the positive charging cable
- Spark protection means that if you accidentally allow the cable ends to come into contact with one another, or with another metal source, there will be no resulting spark
- Automatic chargers can automatically switch the type of charging they are doing from an initial charge to a float or maintenance charge so you do not have to worry about overcharging your battery
- Some chargers can charge multiple batteries at the same time
- You want a charger that can be used on the different types of batteries you have; such as marine batteries, car batteries, tractor and farm equipment batteries, lawn equipment batteries, motorcycles, ATV’s, snowmobiles, and RV’s.
- Anti-slip connector clips will help you to make a secure connection from the charger to the battery terminal
You should also consider where you will be using the battery charger out so you can look at the length of the power cord that it has and determine if the cord is sufficient for the place you have to use it. This is a minor consideration but can make a big difference in the difficulty of connecting your batteries to the device.
Always consider the warranty that is offered by the manufacturer. The length of the warranty and the limitations of the warranty will show you the amount of confidence that the manufacturer has in their product.
Consider the reviews that are provided on the product. Remember that a review is a personal opinion, not a solid fact, so read the negative and the positive reviews and see what things are mentioned repeatedly by different reviewers.
Consider the price of the unit last. It is always nice to save money and buy something that is less expensive when we can, but quality and functionality are far more important than the amount of money that we can save by purchasing an item with fewer features, or with worse customer satisfaction ratings.
AGM Battery Technology
An AGM battery is an absorbed glass material battery. These batteries are also referred to as starved electrolyte batteries. The technology was first used in the 1980s. The original intention for this type of battery was to reduce the weight on military aircraft and other military vehicles so the vehicles had improved performance.
The resulting battery is lighter than the traditional flooded batteries and does not require a ‘topping off’ charge every six months like a traditional lead-acid battery does. The topping off charge for a lead acid battery is designed to reduce the sulfate build-up that can reduce the strength of the battery, but the sulfate does not build-up in the AGM batteries like it does in the lead acid ones.
The design of these batteries allows the sulfuric acid (commonly called battery acid) that the battery needs to provide power to travel from one plate to another plate through the absorbed glass material rather than remaining in a total liquid state.
The absorbed glass material swells, much like the absorbent material inside a baby diaper swells, and it transfers the electrolytes. If the AGM battery receives a broken case in some type of accident there is very little liquid inside so the electrolytes will not leak from the battery and cause any damages to the vehicle they are in or to the environment. This is a major safety feature that causes the majority of vehicle manufacturers to choose the gel or AGM batteries for their products over traditional flooded batteries.
An AGM battery can be expected to serve you for two to three times longer than the traditional lead acid batteries. A traditional lead acid battery is expected to have a life span of three to five years, but the average AGM battery has an expected life span of six to ten years. This is the reason why you will pay slightly more to purchase a gel battery instead of a lead acid battery.
The absorbed glass material allows the AGM battery to maintain a charge longer when it is exposed to very low or cold temperatures. A lead acid battery cannot tolerate being exposed to freezing temperatures without losing some of its power, but the AGM batteries tolerate the cold very well and remain reliable for much longer times in freezing conditions.
The biggest drawback to the AGM technology is that the batteries that have this technology are more sensitive to over-charging and easier to damage while charging. This is the reason why purchasing a battery charger that is specifically designed for this type of battery will help prolong the life of your battery.
How AGM Battery Chargers are Different from Other Battery Chargers
There are several differences between the chargers designed to provide a charge to an AGM battery and chargers designed to charge traditional flooded batteries and other batter types.
The most common differences are:
- The AGM battery charger is designed to provide a charge at a slower rate of speed so the absorbed glass material can fully receive the charge
- The AGM battery charger will be more likely to have a safety feature that prevents it from overcharging the battery and doing internal damage
- The AGM battery charger will more likely be an automatic charger that can switch from initial charge to maintenance charge when you are not present. These chargers will sense when the battery starts to lose some power and switch back so they keep the battery hot and ready at all times
- The AGM battery chargers are more likely to contain the newer safety technology that prevents reverse polarity or sparking when the ends of the connection cables come into contact with each other. This spark reduction can prevent damage to you, your battery and your vehicle.
- The AGM battery charger is more likely to have newer technology that allows it to do other jobs like charge your electronic devices, or have LED work lights and LED indicator lights to help you use the device.
Charging the AGM Battery
Charging the AGM battery is basically no different than charging the other battery types. The biggest difference in charging the AGM battery is that you do not have to give these batteries a finishing charge twice a year. The older batteries, like the flooded batteries, or the lead-acid batteries have a tendency to build up a sulfate residue over time.
That sulfate residue reduces the power and the life span of the battery. The difference between being able to crank your vehicle and being stranded with a dead battery and being able to simply turn the key and go is often due to whether the battery has a sulfate build-up. The AGM battery does not have the sulfate build-up issues found with other batteries so you do not need to charge these batteries unless they are losing power or have become depleted.
Let’s watch this cool step by step video of how to charge AGM battery:
When you charge an AGM battery it is recommended that you do so at a slower speed than you might would use if you were charging a lead acid battery. This is due to the fact that the AGM battery cannot tolerate being charged over its capacity. Overcharging these batteries is the biggest reason why the batteries have to be replaced before their maximum life expectancy is met.
You can prevent this from occurring by buying a battery charger that is automatic and senses when the battery is charged so it switches from providing the faster initial charge to providing a slow trickle charge that simply maintains the amount of charge the battery has.
You can use an older model battery charger, or a battery charger designed for flooded batteries to charge your AGM battery. You just have to pay close attention so that you do not overcharge your battery.
The best AGM battery charger is the one that provides you with the ability to charge your AGM battery without damaging the battery, or without having to monitor the charger constantly.
An automatic charging unit will allow you to safely provide a charge, and maintain your batteries on your car, truck, watercraft, motorcycles, lawn equipment, farm equipment, and sporting equipment.
By learning the basics about the types of batteries your equipment is powered by, and the needs of those types of batteries, then you can expect to get the maximum life out of the batteries and enjoy your vehicles more.