Anwser:Two of the most common terms that we hear from customers are AGM and GEL, which are often mistaken for the other more than half the time. We have already explained what exactly an AGM battery is, now we will be taking a look into what sets a true GEL battery apart from the rest of the sealed lead acid pack.
Okay, first and foremost, the term GEL is short for gelified electrolyte lead acid. In other words, a true GEL battery will actually contain a gelatin in place of the typical free flowing electrolyte (battery acid).  A special gelling agent is added to the electrolyte to reduce the movement of acid inside of the battery – the process literally turns the acid mixture into a gooey Jell-O like substance. Due to this mixture of Jell-O like acid, the GEL battery is designed with special one way safety valves in place of open vents typically found on wet-cell batteries (non-sealed), this method of venting allows the internal gasses to recombine back into water in the battery, greatly reducing gassing.