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Published Sep. 30, 2021

Best AGM Battery Charger Reviews & Recommendations

The Noco Genius GEN5X3 is the latest charger from Noco and is smaller and more powerful than the company’s previous version. It features three bank ports (5 amps per bank). This battery charger is capable of providing power to up to three batteries at once. Its versatility doesn’t end there. It can also charge lead-acid, lithium-ion, deep-cycle, gel, and AGM batteries.

Noco’s charger also has an integrated thermal sensor that detects the ambient temperature and can ensure proper charging in hot and cold climates. Additionally, there’s a repair mode that can repair old or damaged batteries. The unit was designed to be durable, and it’s waterproof. However, the lack of a quick-connect means that batteries have to be removed to charge them. If you cut the leads to extend the DC wires, which may be necessary for some applications, it voids the warranty.

Specs
  • Brand Noco
  • Model GEN5X3
  • Weight 6.09 pounds
  • Amps 15
PROS

Multiple banks to charge different types of batteries

Sturdy design

Strong amperage output

Waterproof

CONS

Requires batteries to be disconnected

Cutting leads to extend them voids warranty

A bit complicated to use

Black+Decker’s BC15BD AGM battery charger is designed to maintain a 12-volt AGM, gel, and wet battery in automotive and marine applications. It connects to the terminals via alligator clamps, and the BC15BD has a three-stage charging system that automatically switches from fast charge to top off to trickle charge to ensure your battery’s longevity. The charger also features reverse polarity protection, as well as an easy-to-read LCD screen that displays charging status and battery status.

An automatic shutoff kills power to the battery when it is fully charged, which allows you to set it and walk away without worrying about overcharging or overheating. It also includes a patented alternator check that indicates if the alternator is maintaining battery level. Unfortunately, if the unit sits unused for a period of time, it may suffer from performance issues or misdiagnosis of a battery charge.

Specs
  • Brand Black+Decker
  • Model BC15BD
  • Weight 5.5 pounds
  • Amps 15
PROS

Three-phase charging

Built-in alternator check

Easy to read LCD screen

Simple to connect

CONS

Does not charge 6-volt batteries

Instructions can be difficult

Charging process can be lengthy

The Schumacher charger and maintainer works across 15/3 amps and 6/12 volts, in marine and automotive applications, giving you the flexibility to use it for a variety of vehicles. You can expect a 15-amp rapid charge at a 3-amp rate, and it will charge standard, AGM, gel, and deep-cycle batteries. It features a handy auto voltage detection, so it can switch between 6-volt and 12-volt batteries.

The LED screen adds to the simplicity of operation, but just in case, the SC1280 also has a reverse hookup protection feature that prevents the charger from operating if clamps are reversed. Its compact, lightweight shell is easy to transport as well.
The SC1280 isn’t perfect, and even though the unit has an automatic shut-off feature, if it fails it can cause batteries to swell and overheat, and if the unit detects inaccurately that a battery is 6 volt instead of 12 volt, there is no way to override it.

Specs
  • Brand Schumacher
  • Model SC1280
  • Weight 3.02 pounds
  • Amps 15
PROS

Covers 6- and 12-volt batteries

Easy transport

Automatic voltage detection

Reverse hookup protection

CONS

Could cause batteries to swell

Auto shut-off feature could fail

Battery discharge detection may not function correctly

Optima is known throughout the automotive world for top-spec batteries and chargers. The Optima Digital 1200 12V Performance battery charger is designed to be both durable and reliable, although that comes with a price. It’s built to charge, condition, and maintain 12-volt AGM and flooded batteries at up to 12 amps, and it features an LCD that displays battery-charging, fill rate, mode settings, and fault messages for an easier user experience.

The battery charger also features a built-in LED work light, and you also get charging ports for your smartphone or any other device that requires a USB port. The outer plastic shell could be more robust, but we don’t think most will be slamming the charger onto the floor. Additionally, the unit may not switch to maintenance mode after a battery is fully charged, so you’ll have to keep an eye on it.

Specs
  • Brand Optima Digital
  • Model 1200 12V
  • Weight 7.75 pounds
  • Amps 12
PROS

USB charging ports

LCD screen and integrated charging clamp LED light

Quick charge

Easy to carry around

CONS

Weak plastic casing

Not cheap

LCD screen may not always work

It may not look like much, but the Battery Tender 12-Volt Junior Automatic Battery Charger includes a four-step charging program to get your battery back in working order and keep it there. It starts with an initialization mode that moves to bulk, charge, and then a float mode, which ensures the battery power remains in peak performance.

The unit will charge 12-volt lead acid, AGM, and gel batteries, and you can set it and forget it, allowing it to keep your battery topped up for quick use. Another benefit of the Battery Tender model is its two-color LED indicator light. Since there is no screen, the lights let you know if the battery is getting a charge. It isn’t waterproof or water resistant, so don’t leave it outside, nor is it designed to be super durable, so handle with care.

Specs
  • Brand Battery Tender
  • Model 021-0123
  • Weight 1.8 pounds
  • Amps 0.75
PROS

Microcontroller technology verifies correct connection

Fast charge

Simple to connect

Compact and easy to carry around

CONS

Not waterproof or water resistant

Not that durable

Cord feels flimsy

How We Selected the Products 

We researched dozens of AGM battery chargers to help you find the right option for your needs. We weighed those assessments against our own expertise, which includes nearly 20 years of experience wrenching in our own driveways. We also prioritized well-known, high-quality charger brands and owner reports that spoke to construction quality, ease of use, and durability. 

Our product selections, rankings, and awards for this story are based on research. While we haven’t conducted real-world testing on all of these products yet, we’ve looked at consumer testimonials and data, tutorials, and general discussions on social media and in forums. We also consider price and specification in the context of the segment. And, of course, we rely on our institutional knowledge of the automotive landscape to weed out weak products.

Buying Guide/What to Look for 

What to Consider When Buying an AGM Battery Charger

We’ve put together a list of the things you need to know if you need a new AGM battery charger.

The most common types of AGM battery chargers

It’s important to understand the various features and capabilities of an AGM battery charger, as it isn’t just a device used to charge your battery. You will find three different types of battery-enabling devices — the charger, the maintainer, and the restorer — and they all work in various ways to make sure your battery is functioning correctly. Some options on our list tackle multiple features, so read closely. 

Charger

This is what people will generally go for when it comes to topping off a battery. In basic terms, it does exactly what it says. These types of battery chargers breathe new life back into batteries drained of power. They are the most common type of battery chargers and are equipped to handle several types of batteries, and they come in a variety of amperage and voltage options to restore the juice back into your dead battery.

Maintainer

The maintainer keeps the battery charged while the vehicle is not being used. While it won’t fully charge the battery or restore dead cells, the maintainer will ensure the battery doesn’t lose its charge while stationary, so it will be ready for your next outing whenever you are.

Restorer

One of the least common types of battery chargers, a restorer breaks down contaminants built up in the battery’s cells that can block the battery from getting power. Batteries that are blocked are unable to function properly and will lose their charge or not work at all. Restorers clear the cell blockage so the battery can get more power. A restorer is typically found in heavy-duty garages, mechanic shops, and workshops. 

AGM Battery Charger Tips and Tricks

Be aware of a few things before you purchase your AGM battery charger. Not all are created equal, so focus on specific features instead. Here are a couple things to look for before making a purchase.

Discharge rating

One of the main features is the discharge rating of the battery charger. Each one will come with its own rating, and they aren’t all the same. The rating will be denoted in ampere hours. Ampere hours measure the amount of current a battery can provide in just one hour. A 100-aH battery is able to provide up to 100 amperes of current in a single hour.

Safety

Battery chargers use electricity and can be dangerous when in use. The best battery chargers are equipped with their own safety features to protect you, the battery, and the charger. Many will come with an automatic discharge feature that controls the amount of juice that flows from the charger to the battery. Once it reaches a certain amount or fully charges the battery, the charger should shut off so you don’t use too much electricity or risk overcharging your battery. Other chargers come with protections to keep from damaging the battery in case the cables are improperly attached.

Tips for using AGM battery chargers

Knowing how to take care of your battery charger can save you time, effort, and money in the long run. There are several things you should understand about them before connecting one to your battery. 

Tips

  • To get the best out of your charger, clean the cables before each use. Dirt or dust can build up and reduce the amount of charge you get.
  • The white powder collecting on your battery terminals is dried sulfuric acid. Don’t touch it as it can burn your skin. Consider using gloves or a wire brush to get rid of the acid safely. 
  • Always make sure you connect the correct cable to the correct terminal. Know which cable is the positive and the negative charge before connecting them to the battery. A plus sign stands for positive and the cable is red, while a minus sign stands for negative and is black.

AGM Battery Charger FAQs

Q. What’s the difference between an AGM battery and a regular car battery?

AGM (absorbed glass mat) is a newer technology compared to the conventional lead-acid battery that was invented 160 years ago. Regular batteries are made from thin lead plates  that are flooded with sulfuric acid and water. AGM is made from glass mats cushioning the ultra-thin lead plates. The additional plates mean faster recharging and a longer lifespan. Some estimates claim that an AGM battery will last three times longer than a conventional car battery. 

Q. Will any battery charger charge an AGM battery?

No, some chargers are designed to provide small amounts of power over a longer time, while others are designed to provide a lot of power at once. Our buyer’s guide will steer you to some of the best chargers to use with AGM batteries. 

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

It is, generally speaking. If you place your hand on the battery during charging, it should feel a bit warm. If it is getting too warm during the charging stage, it makes sense to take it off the charger to let it cool, then resume charging. 

Final Thoughts

Our choice for the overall best AGM battery charger goes to the Noco Genius Battery Charger. The latest charger from Noco is smaller and more powerful than the previous version. It features multiple bank ports, making it a versatile and effective option. It features a sturdy design, a strong amperage output, and it’s waterproof. So no matter your task, the GEN5X3 is up to the challenge. 

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