Deep-Cycle AGM Battery

Deep cycle batteries are designed to provide sustained power over long periods. The level of discharge is deeper compared to other types of batteries. With Absorbed Glass Mat (AGM) batteries, you gain a maintenance-free deep cycle battery for use in a variety of situations.

AGM batteries differ from flooded lead–acid batteries in that the electrolyte are held in the glass mats, as opposed to freely flooding the plates. Very thin glass fibers are woven into a mat to increase the surface area enough to hold a sufficient amount of electrolyte on the cells for their lifetime. The fibers that compose the fine glass mat do not absorb and are not affected by the acidic electrolyte. These mats are wrung out 2–5% after being soaked in acids just prior to finish manufacturing.

The plates in an AGM battery may be of any shape. Some are flat, whereas others are bent or rolled. Both deep cycle and starting type of AGM batteries, are built into a rectangular case according to Battery Council International (BCI) battery code specifications.

AGM batteries are one of the main types of sealed rechargeable batteries. Unlike a flooded battery, the environment is sealed to keep the electrolytes inside. The electrolyte is entirely absorbed inside the unit, eliminating the need to add water.

As with other deep cycle batteries, an AGM battery includes lead plates and electrolytes. Fiberglass is included between the plates to hold the electrolyte in place. A glass mat separator is used to wick electrolytes between the plates. The design allows the fiberglass to become saturated with electrolytes.

The electrolyte is moved from the glass mat separator to the battery plates as needed to carry an electrical charge. The mat holds enough electrolytes to deliver its entire capacity. Thanks to this design, if the battery is damaged or tipped, the electrolyte does not spill.

People often refer to AGM batteries as maintenance-free. You do not need to add water to service the battery. The sealed design of a deep cycle AGM battery allows it to be used in a wide variety of applications.

These types of batteries were originally used in everything from motorcycles and military aircraft to submarines. It is a recommended option for situations where battery maintenance is difficult to carry out. Other applications include backup power for off-grid power systems.