How to Charge AGM Battery in Simple 7 Steps?

GM is an abbreviation of Absorbent Glass Mat and the AGM battery is such a battery that has a combination of acid and lead. These batteries are developed to meet the higher demands of current in modern vehicles of this era. Many start-stop apps are also run on these batteries.

These batteries are entirely vibration resistant, tightly sealed, and do not require any special maintenance. The quality to recycle makes them far better than standard batteries. They entered the markets of the US and Europe in 2013 as the electrical requirement increased rapidly in modern sports cars and other devices.

There is a massive demand for these batteries throughout the world due to their simple method of charging and efficiency. A report by Marketwatch shows the sales of 14 billion US dollars in America in the year 2018. A rise to more than 16 billion dollars is predicted up to 2025. 

Their demand is increasing in Asia and South America, also as the local auto industry is growing.

Structure of AGM Batteries

There is a partition of the absorbent glass mat between the negative and positive plates of the battery. This is the main reason that the battery does not spill any acid due to the presence of this glass mat. This is also responsible for holding the battery at its place.

In the case of plastic, these plates are firmly pressed in the cells under a lot of pressure. These batteries have a better life because the compression does not allow plates to shed anything due to cycling. There are higher power and internal resistance due to this compression.

To charge AGM battery always see the condition of its terminals.

Benefits of AGM Batteries

These batteries have revolutionized the modern auto industry because of the following reasons.

  • They take a short time to charge.
  • They have complete resistance from vibration.
  • They are made for harsh weather conditions.
  • The capacity to bear an electrical load is high.
  • The acid is not spilled, and it does not require any maintenance.
  • There is no need to add water.

Charging of the AGM batteries

The importance of the charging process can be seen by the fact that it not only increases the battery life but also can renew a depleted battery. The modern chargers of the AGM batteries have such microprocessors that can assess the required voltage of the battery. The following steps must be kept in mind:

1. Attach an AGM battery with the Jumper Wire:

The first step in charging is to link an uncharged battery to a charged one with the jumper wires. You must properly connect the positive plate of the battery with the positive one of a charged battery.

This is a crucial step because if it is not done with care, the whole process of charging could fail. This single step will determine the fate of all other steps.

2. Always buy the Suggested Charger:

There are a lot of chargers available in the market based on the type of device they charge. There is a difference of power among the chargers. The demand for energy by the device selects the type of charger.

There is no feature of dual capacity in any charger. Always take the size of your battery into account before selecting your charger. The size of the battery is proportional to the size of the charger.

The size of the charger does not mean its physical size but the amperes which show its capacity.

3. Relate a Good Battery with the Charger:

The charging of an AGM battery directly depends on the type of charger selected. You must create a secure link between your old battery and the charger for the proper charging process.

If you do not choose the appropriate charger, it cannot charge your battery correctly.If the charger is of high-quality, it would immediately start to give the current to your battery.

This procedure is continued for some time. Your old battery must never be overcharged as it may seriously affect its performance.

4. Give an Hour to the Battery:

If you want to check, either your battery is charging or not give it an hour of charging. After one hour, check if it is turning hot. If the battery is hot, then it is charging appropriately, and if it is the same as before charging, it is not.

If your battery is extra hot, then there may be an issue with your battery. The temperature gives an idea about the health of the battery. Keep it charging; you must not halt its charging process.

5. Maintenance of an Appropriate Temperature:

The process of charging an AGM battery is fixed. These batteries are not charged with any conventional procedures. There is a fixed range of temperatures, the knowledge of which is necessary for you.

The temperature range of charging an AGM battery is from 0oC to 400oC. The rate of charging your battery highly depends on this range. Warming up of your battery is a sign of charging, but if the battery becomes very hot, you should quickly remove the charger.

When the battery is cool, connect it again.

6. Using a Voltmeter:

When the charging of the battery is completed by correctly taking all its steps, the condition of the discharged battery is checked. A voltmeter is required to calculate the amperes of an AGM battery.

Three are some specific volts which show if the battery should be charged more or not. 10.5V is considered an indicator to continue the process of charging. When the battery does not show any reading, it is a sign of a big problem in the battery.

The issue must be resolved before continuing the charging.

7. Know the difference between other batteries and AGM battery:

It’s a big misconception that charging an AGM battery is similar to charging your laptop battery. There is a lot of difference in charging a lithium laptop battery and an AGM battery. 

The charging procedures are completely different. There is a significant difference between the chargers of both batteries.

The selection of a compatible charger is essential in the charging process.


By following the steps mentioned above, you may easily charge your AGM battery. But you must collect as much knowledge about the procedure as you can. The choice of a charger plays a vital role in the charging of AGM batteries.

John S.

Hello guys! I'm a 37-years-old author, traveler, writer, blogger, and a camper. I enjoy life as much as I can and love to visit beautiful places in my RV. That's why while traveling I have decided to dedicate some time to share my experiences with everyone that might be interested in traveling, camping, and RVs.