Reviewerst Chargers Best AGM Battery Chargers Review

AGM (absorbent glass mat) batteries have a lot of advantages over traditional batteries. Enhanced reliability, high performance even at low temperatures, and leakage resistance make it a perfect choice for many car owners.

However, you might need a special charger to maintain the AGM battery in top condition. But picking the best AGM battery chargers that would match your battery can be tricky. AGM batteries are sensitive to overcharging, so you will need a smart charger that would help you control the charging process without your direct involvement.

In this review, I will list the most popular options so that you can save time by eliminating the need for your research. Besides, I will cover the critical features when selecting the AGM battery charger if you want to go deeper into this topic.

Our pick
Best AGM Battery Charger
NOCO GENIUS 5
Best AGM Battery Charger
The all-new GENIUS5, one of our most powerful, highest-performing, energy-efficient, and compact chargers yet.
Name Voltage Charging current Battery capacity Weight Review
NOCO GENIUS 5best overall 6V / 12V 5 A 120 Ah 1.6 lbs / 0.72 kg Review
Battery Tender Juniorbudget 12 V 0,75 A Not applicable 1 lbs / 0.45 kg Review
NOCO GENIUS 10 most powerful 6V / 12V 10 A 230 Ah 4 lbs / 1.81 kg Review

Can I charge an AGM battery with a normal charger?

No, I am afraid you can’t charge an AGM battery with an ordinary charger without killing it. Why do AGM batteries need a special charger? The reason is that AGM batteries are more stable, and they require special charger parameters to maintain flawless battery operation after charging.

The peculiar feature of AGM battery chargers is that they operate slowly and on low voltage, and these are perfect conditions for AGM batteries.

Special chargers for AGM batteries have in-built microprocessors that estimate the battery level, capacity, and condition. Thanks to this, the smart device optimizes the charging experience to prevent overcharging. A conventional charger can easily overcharge the battery (and AGM batteries are sensitive to this) and kill it sooner than you expected.

Best AGM battery chargers reviews

NOCO GENIUS 5 – best overall

NOCO GENIUS 5

The NOCO GENIUS 5 is a universal charger that would cover a wide range of your charging needs, including recovering an AGM battery.

Regardless of its compact size, this model is powerful, energy-efficient, and high-performance. It is compatible with 12V AGM batteries but can also bring 6-volt and 12-volt lead-acid automotive, marine, and deep-cycle batteries to life. The charging current is 5A, and the output power is 75W max, which is sufficient for battery recovery.

Similar to NOCO GENIUS 10, the GENIUS 5 model has advanced diagnostics features that include high voltage level, battery condition, reverse connection, and unit temperature. But this model doesn’t support 6V AGM batteries, unlike a more advanced product of this brand.

NOCO GENIUS 5 Photo

The charger detects the battery charging needs and provides enough power without overcharging thanks to the thermal sensor. Even when the battery is dead, the NOCO GENIUS 5 will allow you to manually start charging even for the battery with 0 volts. But mind that it might take longer than the manual suggests to charge the battery.

This worry-free battery charger comes with an interchangeable connector, battery clamps, integrated eyelets, self-tapping screws, mounting bracket with strap, and a guide.

Being a multifunctional and powerful unit, the NOCO GENIUS 5 is the best AGM battery charger that offers the utmost functionality and flawless performance.

Key specs

  • Voltage, V : 6/12
  • Charging current, A : 5
  • Battery capacity, Ah : 120
  • Output power, W : 75
  • Weight, lbs/kg : 1.6 / 0.72
  • Dimensions, inch/cm : ‎4.61 x 3.43 x 7.95 / 11.7 x 8.71 x 20.19

Pros

  • Compatible with various batteries, including 12V AGM
  • 5A charging current for faster charging
  • 75W output power to cover various needs
  • Advanced diagnostics features and worry-free charging control.

Cons

  • Might charge longer than states in the guide.

Battery Tender Junior – budget

Battery Tender Junior

Recover your AGM battery without the risk of overcharging it with Battery Tender Junior.

This 12V charger and maintainer is compatible with gel, lead-acid, and AGM batteries. By offering 750mA of charging current, it charges and maintains motorcycles, dirt bikes, ATVs, UTVs, lawnmowers, and other tools. It also maintains cars, so it might not start your car when its battery is dead.

The unit comes with a 12-foot output cord, fused alligator clips, a fused ring terminal harness, and quick disconnect cables. It’s easy to use as the charger will automatically switch to a float mode to maintain the optimal battery level when it is fully charged.

Battery Tender Junior Photo

Unlike the CTEK MXS 5.0 with more informative indicators, this product has only one two-color LED light that shows that the battery is charging and the voltage drops if it occurs. The charger is also enhanced with reverse polarity protection, so the battery is protected even if you confuse the power supply polarity.

The product is made in China, which has positively affected the price but killed the quality of the construction – the maintainer feels flimsy and poorly built.

Overall, the 750mA Battery Tender Junior is a worthy budget-friendly option if you are looking for a unit to maintain your car’s battery in top condition.

Key specs

  • Voltage, V : 12
  • Charging current, A : 0,75
  • Weight, lbs/kg : 1 / 0.45
  • Dimensions, inch/cm : ‎8 x 4 x 9 / 20.32 x 10.16 x 22.86

Pros

  • Great for maintaining fully charged car batteries
  • Compatible with 12V AGM batteries
  • Automatically switches to float mode once fully charged.

Cons

  • It’s a car battery maintainer, so it won’t charge the dead battery.
  • Low construction quality.

NOCO GENIUS 10 – most powerful

NOCO GENIUS 10

The advanced NOCO GENIUS 10 charger comes with numerous outstanding features catered to various charging needs and battery types.

Compared to the similar product in the line – NOCO GENIUS 5 with 5 Amps charging current, 120 Ah battery capacity, and 75 W output power, the NOCO GENIUS 10 can be called a true beast. It provides 10A of charging current and 150W of output energy, which results in faster charging and more stable performance. It is also capable of fully recovering the batteries with up to 230 Ah through both 6V and 12V AGM modes.

The pack includes the charger/maintainer, two self-tapping screws, battery clamps, mounting bracket, and strap.

NOCO GENIUS 10 Photo

Enjoy worry-free and precise charging due to a smart control feature. It will automatically assess the condition of the battery and its capacity. It will handle even a dead battery with one or fewer volts left.

The charger itself is compact, so you can also grab it with you in the trunk. But because this charger is too powerful, I noticed that the AGM battery gets really hot during recharging.

The NOCO GENIUS 10 boasted of nice-to-have parameters, making it applicable for a wide range of vehicles. But its main perk is the power, making it a good charger for AGM batteries that covers various needs.

Key specs

  • Voltage, V : 6/12
  • Charging current, A : 10
  • Battery capacity, Ah : 230
  • Output power, W : 150
  • Weight, lbs/kg : 4 / 1.81
  • Dimensions, inch/cm : 4.41 x 4.48 x 9.1 / 11.2 x 11.37 x 23.11

Pros

  • Compatible with 6V and 12V AGM batteries
  • 10 Amps of charging current for faster use
  • 150W of output energy for advanced power
  • Fully charges 230 Ah batteries.

Cons

  • Some batteries get too hot while charging.

CTEK MXS 5.0

CTEK MXS 5.0

The CTEK MXS 5.0 is a popular product of a famous Swedish brand manufacturing battery maintainers and chargers.

This smart charger is applicable for batteries up to 110 Ah, so it can recover the battery of the car, motorcycle, boat, and more. At the same time, it works for maintaining 160 Ah batteries. It supports 12V AGM and EFB batteries and supports 14.4/14.7/15.8V. The device generates 4.3A charging current for optimal charging speed.

Similar to Schumacher SC1281, the CTEK MXS 5.0 features a multi-step charging program for enhanced precision, safety, and battery life. Besides, it is a fully automatic microprocessor that controls the charging process and switches between several charging modes for advanced efficiency.

CTEK MXS 5.0 Photo

Thanks to the desulfation feature, you can remove sulfates from the lead plates and prolong the battery service life.

The pack includes the charger, extension cable, clamps, and indicator eyelet. There is also a carry bag for easy storage. There is no screen that shows you what is going on with the battery and the charger, but it has some indicators that might give some hints.

The CTEK MXS 5.0 is a reliable AGM battery charger and maintainer that would extract enough power to charge your battery when it requires maintenance and recharge.

Key specs

  • Voltage, V : 12
  • Charging current, A : 4.3
  • Battery capacity, Ah : 160
  • Weight, lbs/kg : 1.8 / 0.81
  • Dimensions, inch/cm : 11.02 x 5.91 x 2.36 / 28 x 15 x 6

Pros

  • Complete charging cycle for batteries up to 110 Ah and maintenance for 160 Ah batteries
  • 14.4/14.7/15.8V current with 8-step charging
  • Smart microprocessor for care-free and safe charging.

Cons

  • Indicators might not be informative enough.

Schumacher SC1281

Schumacher SC1281

Being specially designed for large batteries, SUVs, or trucks, this Schumacher SC1281 with 62A charge will help you get the standard, AGM, gel, and deep-cycle battery to life.

This is a 6V/12V model with 30 Amps quick boost and 100 Amps jumpstart to recover even fully discharged batteries. Being safe and reliable, it comes with a reverse hook-up protection that won’t let you start the charger if the clamps are connected reverse. Due to smart microprocessors that distribute the current depending on the battery condition, this unit might be your connect-and-forget solution.

In contrast to CTEK MXS 5.0, this unit is a little bulkier due to added features like advanced indicators and the LED screen. You’ll be able to see the charging mode, battery type, rate selection, the condition of the battery, and the charging progress.

Schumacher SC1281 Photo

The charger has a battery and alternator testing feature to help you spot electrical issues (you’ll see them on the panel). There is also a convenient start/stop button for ease of use.

Sometimes, the device won’t stop charging the battery, and the screen will freeze at a certain battery level (like 61% for a couple of hours).

This 6V and 12V AGM battery charger by Schumacher is a powerhouse charger that would handle large batteries like in trucks, SUVs, and other vehicles.

Key specs

  • Voltage, V : 6/12
  • Charging current, A : 4
  • Weight, lbs/kg : 12.7 / 5.73
  • Dimensions, inch/cm : ‎11 x 10 x 8 / 27.94 x 25.4 x 20.32

Pros

  • Informative and detailed panel and LCD screen
  • Compatible with 6/12V AGM batteries
  • Up to 100 Amps of charge current (varies on the mode).

Cons

  • There might be issues with the information accuracy on the screen while charging.

AGM battery chargers buying guide

Voltage сompatibility

Using a random battery charger for AGM batteries that is not compatible with the battery can kill it. Check the voltage parameters of your battery and then look for the charger with the same characteristics. Usually, the batteries operate at 6V to 12V, but you might have a 24V item as well. The charger should produce a current limit 20% higher than the battery capacity, meaning that the maintainer should provide 14.4-14.8V for the 12V AGM battery.

Amperage rating of AGM charger

The ampere rating is responsible for the speed of AGM battery charging. AGM batteries require slow and long charging for long service life, so it is better to get the AGM battery maintainer with an average ampere rating (between 2 to 10 amps). Chargers with higher amperage will charge the battery faster, but they produce a lot of heat, which might cut the lifespan of your battery.

AGM battery chargers safety features

More advanced AGM smart battery charger options come with features that ensure safer charging and longer battery life. For example, the unit with the desulfation mode will prevent the lead sulfate build-ups during discharge, which will ensure a longer battery lifespan and higher efficiency. Smart chargers also monitor the condition of the battery during all charging stages. Thus, they adapt the charging process based on the battery capacity and state. If you are looking for charging customization, consider the device with an advanced microprocessor.

FAQ

Can a dead AGM battery be charged?

Charging a dead AGM battery is possible, but it is not always easy. AGM batteries are designed to resist overcharging and undercharging, so there is some flexibility in how you charge them. However, if your battery is completely dead, it may be necessary to use a special charger designed for AGM batteries.

Is it better to charge an AGM battery in one go or several shorter sessions?

It is usually better to charge the battery in one go, preventing excessive overcharging. Charging a battery multiple times can lead to an imbalance between individual cells, leading to reduced capacity and shorter life.

Is it normal for an AGM battery to heat up during charging?

AGM batteries are designed to resist overcharging, so the battery temperature should not rise too much during charging. If your AGM battery is heating up excessively while it’s being charged, this may indicate that you’re using the wrong type of charger.

When to charge your AGM battery?

Most AGM batteries can be safely charged at any time, as long as they are not already fully charged. However, it is always a good idea to consult your battery’s owner’s manual to make sure you’re using the correct charging method. It is also best to charge your dead AGM battery once a month during periods of disuse.

What size charger do I need for the AGM battery?

The size of the charger you need will depend on the battery’s amp-hour rating. You can find this information in the owner’s manual or on the battery itself. Chargers are usually rated in watts, so make sure you select a charger equal to or greater than the wattage rating of your battery.

Is it safe to leave an AGM battery charger on overnight?

Charging an AGM battery overnight is generally safe, but it is always a good idea to consult the owner’s manual to be sure. Some chargers include safety features that will automatically turn off the charger if the battery becomes too hot or fully charged.

What should I do if my new AGM battery won’t hold a charge?

If your new AGM battery doesn’t hold a charge, there may be something wrong with the battery itself. You can take the battery to a local dealer or manufacturer for inspection and repair. Alternatively, you can buy a new battery and recycle the old one through a local recycling program.

Can a dead AGM battery be charged?

Charging a dead AGM battery is possible, but it is not always easy. AGM batteries are designed to resist overcharging and undercharging, so there is some flexibility in how you charge them. However, if your battery is completely dead, it may be necessary to use a special charger designed for AGM batteries.