Why Charging an AGM Battery Is Different and How to Do It

JAN.09,2024

Automotive Lead-Acid Batteries: Key Features

The superior performance of AGM batteries surpasses that of both conventional and improved flooded batteries. They are swiftly replacing other batteries as the manufacturer’s first option. Because AGM batteries may be used as deep cycle and starting batteries, they are also suitable for use in boats and recreational vehicles. Deep cycle AGM batteries have an extended runtime between charges without deteriorating the battery.

Nevertheless, AGMs do require recharging. Naturally, charging a lead-acid battery that is among the most advanced would differ from charging a standard automobile battery.

How Is An AGM Battery Charged?

Remove all jewelry, put on safety glasses, and move outside or to a well-ventilated place before doing anything else.

Fit your AGM battery charger into the socket. Observe any further guidelines provided by your particular charger.

Attach a backup power source to the OBD-II port for onboard diagnostics.

To keep the negative terminal of the car from touching any metal, disconnect it and cover it with a rag, glove, or other object. Although the negative cable is typically black, you can also check the cable for the minus (-) symbol.

PLEASE NOTE: On your charger, be sure to select either Absorbed or AGM for the battery type. When you attach a smart charger, it might recognise the voltage and type of battery, but don’t rely only on it. Your AGM battery’s voltage should be matched by selecting 12 volts.

Attach the charger to the vehicle’s battery posts. Make sure the indication lights are set to Absorbed or AGM by checking them once again.

For an AGM battery to be fully charged, start the charger and give it two to eight hours.

When the charger is finished, disconnect it from the battery. The indicator light on your charger will turn off when the battery finished charging completely. Once more, keep the charger’s clamps away from the unfastened negative clamp on the battery.

Reattach the negative terminal of the car to the battery. Cut off the backup battery. You’re now prepared to embark on a new journey.

Your car’s battery will warm up after charging. The water in the battery evaporates if it becomes too hot. The liquid inside so becomes increasingly acidic. This implies a considerably faster internal deterioration of the battery. You can solve this by gradually charging your battery. Its charge should be increased without its temperature being raised.

How Long Does the Recharging Process Take An AGM Battery?

Approximately two to eight hours, it is based on the power specifications of the AGM battery, its current level of drain, and the amps of the charger. Generally speaking, AGM batteries charge far more quickly than conventional flooded batteries.

As a general rule of thumb, to calculate how long it will take to charge a battery, divide its amps by the amps of your charger.

Regular lead-acid batteries often have fewer amps than AGM batteries. Your AGM deep cycle or dual purpose batteries are what you have for this reason. Compared to a normal automobile battery, an AGM battery has a higher amp capacity. The high Ah ratings that an absorbed glass mat battery possesses over a flooded battery of the same dimension demonstrate this.

An AGM battery rated for 70 Ah is the MTZ-48/H6. It could be refilled in 14h using a small, 5ah AGM compliant charger (70ah / 5ah = 14h). However, it could be charged completely in 3.5 hours with a 20-amp charger. It would be impossible for a typical car battery to charge at 20 amps for longer than 20 minutes, much less three hours.

Always wear safety goggles and protect your hands and eyes when charging an automobile battery. Remove whatever jewelry you may have.

In What Ways Might My Charger Be Able to Charge AGM Batteries?

Your battery charger is compatible if it has an AGM or Absorbed setting on its display face.

If you’re not sure it, look online or at a reputable battery retailer for an AGM-compatible charger.

An AGM battery can endure for many years in your vehicle, boat, or recreational vehicle. The best way to ensure that it lasts as long as possible is to keep it charged using the appropriate battery charger.

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