Lead acid batteries come in two basic architectures: deep cycle and starter types. The deep cycle battery is designed for maximum capacity and high cycle count and is the most used type of batteries in  photovoltaic energy generation. This is possible using thick lead plates. Typical applications: are golf carts, wheelchairs, people movers, scissor lifts and RVs. Starter batteries, in comparison, are made for maximum CCA (cold cranking amp). The battery maker obtains a CCA status by adding extra plates to get a large surface area for maximum conductivity. The plates are thinner. Capacity and deep cycling are less important for automotive because the battery is being recharged while driving. If continuously cycled, the thin lead plates of the starter battery would wear-down rather quickly. As a rule of thumb, the heavier the battery, the more lead it contains and the longer it will last.

Sealed Batteries (AGM and GEL Batteries). Alternative energy industry works very extensively with two type of sealed batteries: AGM or Absorbed Glass Mat batteries and on the other hand GEL batteries. In both cases we talk about Captive Electrolyte Batteries. Some of the general features of Captive Electrolyte Batteries are: 1.They do not require water addition or a regular maintenance making them the preferred choice for remote applications. 2. Are working very well in cold temperatures. 3.Are equipped with a relief vent for overcharge pressures. 4. Are spill proof and very easy to carry. 5. Are not the best solution for overheated environment. 6.They are equipped with a Catalytic Recombination Cap or CRC, a features witch allows the Oxygen Gas relies from the positive plates to recombine with the Hydrogen Gas relies by the negative plates and recombine in water and replenish the electrolytic solution.

AGM  (Absorbed Glass Mat) is a special design glass mat with the electrolyte absorbed into fibre glass mats which are sandwiched between plates AGM batteries contain only enough liquid to keep the mat wet with the electrolyte and if the battery is broken no free liquid is available to leak out.

Gel Cell batteries contain a silica type gel that the battery electrolyte is suspended in and allows electrons to flow between plates but will not leak from the battery if the case is broken.

AGM Batteries are the most used type of batteries as sealed batteries. The ratio they are used is 1 to 100 (  1 Gel Cell by at least 100 AGM) AGM is preferred when a high burst of amps it is required. They have a higher life expectancy; measured as cycle life or years remaining.

Gel Cell Batteries are typically more costly and do not offer the same power capacity with the same physical size of AGM battery. The Gel Cell excels in slow discharge rates and slightly higher ambient operating temperatures. Gel Cell Batteries must be recharged correctly or the battery will suffer premature failure.