Deep cycle batteries are designed to be deeply discharged, usually down to between 45% and 75% of it's total capacity. This capability is attributed to the thick plate structure. In contrast, a cranking battery, which consists or smaller plates, is designed to deliver short bursts of high output. Deep cycle batteries can be wet cell or dry cell -VRLA (Valve Rulated Lead Acid). VRLA can be broken down into two categories : AGM (Absorbed Glass Matt) and Gel. Many people use these terms synonymously, but there is a difference in design structure. AGM batteries utilize woven matts to withold the electrolyte, preventing the free flow of acid if the battery case is punctured . This also more allows for a more versitile mounting of the battery because there is no chance of spillage. Gel batteries also possess this non-spillable trait, but contain their electrolye in a difference manner. Gel batteries utilize a gelatin additive that keeps the electrlytle immobile. Both AGM and Gel batteries require no maintenance, are considered to be less hazardous than conventional wet cell batteries, and are ideal in applications that may induce high vibrations.
Deep cycle batteries are typically utilized in applications where the application requires a deep depth of discharge. The most common use of deep cycle batteries are marine applications, such as trolling motors. There are many other uses for deep cycle batteries, including golf carts, industrial sweepers, solar power, wheelchairs, uninterruptible power supplies, and telecommunications. Some car manufacturers are even switching to AGM technology for their factory stock batteries. AGM and Gel automotive batteries, like the ones manufacturered by Optima and Eastpenn/DEKA, arepopular in high performance applications.
Dual Purpose vs Deep Cycle : What's the difference?
Dual purpose batteries combine characteristics of the deep cycle battery and the conventional cranking battery. A hybrid of the two, dual purpose batteries are designed to not only provide a deep depth of discharge, but also have the cranking capaiblities you would find in a conventional starting battery. Dual purpose batteries can be found in both conventional wet cell and VRLA.
Conventional Wet-Cell Deep Cycle Marine Battery
VRLA High performance Gel Battery; Dual Purpose
VRLA AGM Uninterruptible Power Supply / Power Chair Battery