The “AGM” in “AGM battery” stands for “absorbed glass mat.” This refers to the construction that enables the battery to store electrolytes. This type of battery may also be referred to as a sealed lead-acid battery, and should not be confused with a gel battery.
An AGM battery comes with certain rules regarding how to operate the battery without damage. A key component of proper usage for AGM batteries is proper charging.
When charging, the voltage must not ever get above 14.7 volts (V) for a 12-volt battery or 7.35V for a 6-volt battery. Depending on the way the battery will be used, the ideal charge voltage could be less.
Most chargers for AGM batteries charge in stages to keep the battery from getting too hot and to maximize the battery’s capacity. The three stages are bulk, absorption and maintenance.
Determining the battery to use
When deciding which battery to use, there are a variety of factors to consider.
If you are replacing a known battery in a component, the sizing work will already have been completed for you, which makes the process of selecting a new battery much easier. If, however, you need to start from scratch in selecting a battery, the process will be a bit more difficult.
To maximize the life of your AGM battery, the design of the system should utilize 20 to 50 percent of the battery’s capacity but not all of it. Full discharge is defined not by when the battery reaches 0V but, rather, 1.75V per cell.
In a 12-volt battery, then, approximately 10.25V to 10.5V is the target you’re looking for.
To size a battery for an application, you will need to know at least two things:
- How long the voltage will be needed
- How much current will be needed
Current is very similar to flow. Given these two parameters, a 20-hour rate capacity selection chart can be used to determine the size of the battery you will need to purchase. There are some battery manufacturers that go the extra mile in helping you make this selection by publishing specifications for each battery they manufacture. These specifications can be general or specific but must include rating charts that will aid in the design process.
During that design process, it is important to remember that the battery is a storage device. This means that what you remove in terms of energy (watts or amps) from a battery must also eventually be returned to the battery somehow.
Interested in learning more about the proper use of AGM batteries and what you need to consider when determining the kind of battery you need for your specific applications? We encourage you to get in touch with the team at Texford Battery Co with any questions you have about the process of battery selection and usage. Work with our team of experts, and we’ll arm you with all of the details and advice you need to make informed decisions. We look forward to assisting you soon!
Categorised in: Battery Service
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