Battery University Table of Contents. An Idiot's Guide to Deep Cycle Batteries. I have to disagree with most of Mr. Sterlings' pronouncements as they are just plain wrong. Quoting from the referenced article: "So in my simple mind the AGM is about 3 times more expensive than the standard one. And the Gel, about 5 times more. Comparing marine batteries (Gel, Absorbed Glass Mat (AGM), flooded lead acid) Battery Types: Flooded versus AGM and Gel. On the kinds of batteries we may use on board: The most common kind of battery in Marine use today is the lead acid battery.
Using an electrolyte consisting of sulphuric acid, these cells can store impressive amounts of electrical energy in a relatively small space. This energy is stored in chemical form within lead grids mounted inside the battery. The reliance on lead grids and paste explains the great heft of lead-acid batteries. The battery universe is further divided along the lines of battery construction.