Nobody explained how batteries worked when we were kids at school. The curriculum may be improving, but folk still call our factory and ask basic questions every consumer ought to know. We dedicate this page to exploring sealed lead-acid battery fundamentals, so our customers will understand the product better before they order from us.
Two Different Types of Sealed Lead-Acid Batteries
Lead-acid batteries store, and deliver electricity through a chemical reaction between lead, lead dioxide, and sulfuric acid. Cheaper ones flooded with a liquid sulfuric-acid-solution are where you have to top up distilled water. However, these are now largely replaced by valve regulated ones in the consumer market.

Valve regulation uses a one-way pressure-relief system. This innovation suppresses hydrogen gas output, by ensuring the negative plate absorbs the oxygen produced by the positive plate.
There are two types of these VRLA ‘valve-regulated lead-acid’ batteries on the market. The AGM ‘absorbent glass mat’ variety, use fiberglass-mesh separators containing the sulfuric-acid-solution electrolyte. However, the GEL type have a silica dust in their electrolyte solution that turns it into a putty-like substance, or gel.
Exploring Applications for Sealed Lead-Acid Batteries
That’s enough exploring sealed lead-acid battery technology for now. At this point you may be wondering which one is better, an AGM or a Gel battery? The following information should help you decide which type is better for your particular need.
- AGM absorbent glass batteries are able to discharge at a high rate. This makes them the preferred choice for electric auto starters.
- GEL batteries with silica dust in their sulfuric-acid-solution discharge at a lower rate, and withstand corrosion, shock, and vibration better.

That said, both types of VRLA valve-regulated lead-acid batteries are almost maintenance free, and offer a good balance between cost and lifetime. They are safe and reliable, and can function effectively in a wide range of temperatures almost wherever you go. Discover more about our Gel Deep Cycle batteries here.
More Information
AGM Battery Versus Gel Battery: Which Is Better?