OEM

There are three primary types of VRLA batteries, sealed VR wet cell, absorbent glass mat (AGM) and GEL cell. Gel cells add silica dust to the electrolyte, forming a thick putty-like GEL. These are sometimes referred to as "silicone batteries". AGM (absorbent glass mat) batteries feature fiberglass mesh between the battery plates which serves to contain the electrolyte.

Both designs offer advantages and disadvantages compared to conventional batteries and sealed VR wet cells, as well as each other. Due to their construction, the GEL cell and AGM types of VRLA can be mounted in any orientation, and do not require maintenance, which is called "Maintenance Free". They are widely used in large portable electrical devices, off-grid power systems, hybrid storage systems, and similar roles.