Unlike lead-acid batteries, AGM ones have a chemical structure with no electrolyte of a liquid type. The unique AGM batteries composition makes them significantly safer to use than their lead-acid counterparts. As for recharging, they were designed for a slow and low charge. Attempts to do this thing fast will destroy the battery itself. For this reason, the best AGM battery charger is required to charge a glass mat battery.
The vast majority of the devices used for AGM recharge are equipped with special microprocessors that collect information about the power elements. As a result, this processor monitors the state of charge and regulates the voltage and current.
AGM Battery Charger Reviews
The NOCO Genius 5 is a 5A charger that provides both charging and diagnostics of your battery. This small (4.61 x 3.43 x 7.95 inches only) device is designed for daily use and has a zero chance of being recharged.
This model can be the best AGM battery charger in terms of multifunctionality, as it not only can charge your battery but also can protect it from desulfation and work as a maintainer. As a result, it contributes to a trouble-free engine start and increased battery life.
There are LED indicator lights on the unit’s face panel that inform you about the condition of a battery and, of course, show the charging level.
The device has the ability to charge dead batteries with the help of a special sensor that detects batteries that are lower than 1V. You can also use a Force mode which gives you control over the charging process for more accuracy.
The unit is optimized for any weather conditions thanks to the temperature compensation function. This means that the NOCO Genius 5 has the ability to avoid problems associated with extremely high and extremely low temperatures.
- It features IP65 protection, so can be used in wet conditions.
- This model can work with all types of vehicles.
- The device has an auto memory and automatically returns to the last selected mode.
- The display indicators are too small.
- The charger may take longer to charge the battery than specified in the user manual.
The NOCO Genius 10 is a smart multi-voltage charger with fully automatic work. It functions without overcharging, so you can use it for all-season charging of a healthy battery (up to 230Ah).
This 10-Amp charger has wide functionality which allows controlling the charging process manually, restoring damaged batteries, maintaining the charge in a battery that is not in use, etc.
The charger has an ultra-compact design, having 4.41 x 4.48 x 9.1 inches in size. Despite such size, it provides two times more power than smaller models. The face panel contains one Mode button and a number of different LED indicators that show battery charge level, as well as the results of battery diagnostics.
The thermal compensation function optimizes the charging process to different weather conditions.
This AGM deep cycle battery charger comes with two 8 x 1 inches self-tapping screws, mounting brackets, and a strap, so you will get everything you need right out of the box.
- The unit has universal input (100-240 VAC, 50-60Hz).
- The maximized AC power provides 99% of power factor correction.
- The clamps have needle-nose profiles to fit battery terminals of any shape and size.
- The charger is not waterproof, so be careful when using it outside.
- The indicator shows only non-digital charging status, so you won’t be able to see exact numbers.
Battery Tender 021-0123 — AGM battery charger 12V
This device is well-protected from sparks and reserve polarity. A good choice to recharge and maintain the 12-volt lead-acid batteries (Gel Cell and AGM). A four-step charging program is used for this. Armed with an 80-hour safety timer, there will be no overcharge, and the power of the battery stays well-optimized. Can automatically switch to the float mode after a complete battery charge. LED indicators are used to monitor the state of charge. If the voltage drops, the work of the Battery Tender 021-0123 will not stop. The tool is completely automatic and quite easy in use. It has a low weight and goes together with a 12-feet output cord. The five-year warranty period is on.
- If you touch both connectors, there is no chance of a spark.
- Store and use it in the unheated garage without any problems.
- Does not overcharge the battery as it has overload protection.
- This is not a 100% charger. Used only to maintain batteries.
- Despite the long warranty period it quickly breaks.
- Customer service not very polite.
The CTEK has a patented 8-step charging system. It checks the battery status while charging it. Such a system ensures maximum battery life and performance. Pulse charging technology also increases battery life. It charges 12-volt lead-acid batteries (Wet, MF, Gel, AGM, and CA) with four separate modes of operation. Protection against short circuit and reverse polarity is also available, and the patented desulfation function restores slightly sulfated batteries. The charger is safe for children and can be used in any climate. The design is compact, with special mounting holes. A good choice for any batteries up to 150 Ah. Two interchangeable connecting wires are attached. One with clamps and another with eyelet terminals. The CTEK (56-353) MULTI US 7002 can be named as the best AGM battery charger because of its multi-step charging system.
- Equipment is protected by the five-year warranty.
- Various modes for charging.
- Absolutely safe and spark-protected.
- Compact size good for easy transportation.
- There is no ability to jump-start batteries, solely charge.
- Deep cycle batteries are not supported.
- Not as durable as larger models.
This model from Schumacher works as both a charger and an engine starter. As an engine starter, it has enough power to start SUVs and trucks, not to mention smaller vehicles.
This model also has an integrated battery tester that helps find out about the overall condition of your battery (charge level, electrical problems, etc.) to quickly prevent any issues.
The Schumacher AGM battery charger features a multi-stage charging system which is vital to ensure maximum safety of AGM batteries. For even more precision, it also has auto-voltage detection.
In terms of design, this model is not among the most compact ones, measuring 11 x 10 x 8 inches. However, thanks to such a size, the charger has a large and convenient control panel with big LED indicators and a large start/stop push button in the center for ease of use.
The charge is not overly heavy (12.65 pounds) and has an integrated carrying handle. It requires a 120V outlet and comes with a long, 100-inch extension cord for far distances.
- The SC1281 has reverse hook-up protection which means that the charger won’t work if clamps are reversed.
- This model meets the UL Safety standards which means that it’s completely safe for your battery.
- The charger is controlled by a microprocessor which automatically adjusts the amperage rate.
- The manual says about the presence of a desulfation mode but doesn’t say how to activate it.
- Clamps seem a little bit weak.
- The LED indicators are not bright enough, so they are hard to see in the daytime.
With this AGM charger, there will be no fear of battery failure because of sulfation. The automatic full-time desulfator effectively prevents this. Battery life is up to four times longer than batteries requiring little maintenance. The reverse polarity and short-circuit for safety are present as well. A smart temperature sensor adjusts battery voltage during charge. Up to eight batteries at the same time can be connected to the BatteryMinder 128CEC1. For use, there is a need for Y-Connectors 210AY which are sold separately. The 90-240V AC 47-63 Hz input allows using it all over the world. Certified by the California Energy Commission, it meets all efficiency and low energy consumption standards.
- The universal device, suitable for different batteries.
- Quite cheap and environmentally friendly.
- Can predict battery failure.
- Rejects weak batteries as defective.
- The charger cannot detect batteries with an average sulphation level.
This AGM battery trickle charger can charge those batteries that others can’t. It perfectly charges and maintains 12V AGM and flooded batteries. Easy operation thanks to a quick selection accompanied by the LCD charging indicator. For smartphones, cameras, and tablets, the Optima Digital 1200 has a USB port. Does its job very quickly. The performance of the battery will be maximized without the risk of recharging.
- Modern digital 6-speed charging.
- Charges a fully depleted battery.
- Recognizes and charges the battery with 1.25 V voltage.
- Short wires.
- Sometimes it becomes very hot.
NOCO Genius G7200 — best marine AGM battery charger
Universal AGM battery maintainer for fast recharge of AGM, Wet, and Gel batteries. It can work with both 12-volt and 24-volt types. Do not worry about overcharge as modern technology automatically monitors and maintains this process. There is also Repair Mode for batteries which are left uncharged for a long time. The NOCO Genius G7200 can be converted into a five-amp constant current and voltage power supply or be used as a DC power source. An optimized charge mode is a guarantee of safe charging and maintenance of batteries. The spark-proof technology and reverse polarity protection are also onboard. In addition, there is a five-year warranty period.
- Suitable for different batteries.
- It is capable of charging a deep cycle AGM battery two times faster than a conventional charger.
- Will not work on a fully discharged battery.
- Doesn’t work with small batteries for bikes.
A few words about AGM technology
Absorbent Glass Mat constructed in another way than traditional flooded batteries. The AGM uses a so-called starved electrolyte. Between the plates is placed an ultra-thin fiberglass mat impregnated with battery acid up to 95%. This material is packed between the plates and lightly pressed for greater fixation. Since the plates and mats are packed tightly enough, there is no vibration. Such vibration absence helps to avoid internal battery destruction over time during operation. Thus, AGM is durable and safe. In AGM vs standard battery charging competition, the standard win, as their charge is less complicated. The price for AGM durability and safeness is the need for special charging equipment and increased time of recharge.
How to charge AGM battery?
The right approach to AGM battery charging is an extremely important step in ensuring its long-time service. This type of battery is used in a very wide range and correct charging is a key-note of its work for long years. If the AGM batteries are not properly charged, then they will become obsolete prematurely and begin to discharge much faster than before. Also, improper charging of the AGM battery leads to severe heating of the cells, damage to the battery, or even its destruction within a few hours. Just follow four tips and recommendations for charging AGM batteries and it will serve you for many years:
- Buy a recommended charger.
- Understand how charging affects different types of batteries.
- Charge batteries only at the correct temperature.
- Do not worry if the battery gets warm (but not really hot).
At what voltage you must charge the AGM battery?
The optimal numbers of voltage are from 13.8 to 15 V and with the maximum current. However, the last one depends on the characteristics of the charger. When charging lasts for some time and battery voltage approaches the maximum, the charging current should decrease in proportion to AGM voltage increase.
How to determine the charging time?
Everything is simple – the lower the battery charge, the longer it will recharge. The standard charging time of AGM series is between a couple of hours and up to 12 hours or more. Check the temperature of the battery from time to time. If it exceeds 125 degrees Fahrenheit – stop charging it immediately.
Is it possible to charge the AGM battery with standard chargers?
As mentioned above, the AGM battery designed for slow and low charging. Thus, only the use of a charger with microprocessors which adjust the voltage and control the current charge level is allowed. Overcharging can destroy your battery. Thus, standard chargers cannot be used to charge an AGM battery.
How to charge a fully discharged “dead” AGM battery?
So, your AGM is “dead”. What to do now? How to “resurrect” it?
- Buy a modern charger with AGM settings.
- Help a charger to find a deeply discharged AGM battery. To do this, put the several batteries, one of which is completely discharged, in one row. Connect this construction to the charger.
- Take AGM battery to a professional who knows this technology. Most experts will provide “check and charge” procedures for free or for a very small fee.
As practice shows, AGM batteries that may look like a dead one are completely OK. They are just deeply discharged.