THE ROCK BATTERY TYPE Today, there are three distinct types of lead acid batteries being manufactured. Any of these can be designed and built for either starting or deep cycle applications. Those battery types are the wet cell acid, gelled acid or advanced absorbed glass mat (AGM) styles. There are various quality levels available for each type. Final pricing is dependent upon the product design, processing and manufacturing costs. This includes the amount of lead, methods of pasting and curing the plates, degree and type of inter-plate insulation, the quality of the case and the sealing method used. Generally speaking, higher quality means higher cost. The oldest type of lead acid battery is the wet cell or flooded type. This is the least expensive type of battery and it is the most familiar. Therefore, it’s the choice of many racers. The next type of battery is the gelled acid design. These were introduced over 30 years ago and are widely touted for their increased efficiency and safety features. Their acid is immobilized by adding "fumed" silica to the sulfuric acid solution and then sealing the battery. During charge and discharge the gel can develop voids or cracks. These voids and cracks impede acid flow and result in the loss of battery capacity. The latest and most advanced battery technology is the Advanced AGM-style. It was developed to provide increased safety, efficiency and durability over all other existing battery types. In Advanced AGM batteries the acid is absorbed into a very fine glass mat so it is never free to slosh around. Secondly, since the plates are kept “moist” with electrolyte, gas recombination is more efficient. Additionally, since the AGM material has an extremely low electrical resistance, the battery delivers much higher power and efficiency than the older types of batteries. Lastly, Advanced AGM batteries offer an exceptional life cycle.