Batteries That Were Designed for a Solar Power System

Flooded Lead Acid

• Most standalone solar power systems operate on flooded lead-acid batteries. Flooded lead-acid batteries, once the standard batteries for automobiles, contain electrodes composed of grids of metallic lead. The material used for conducting electricity consists of electrodes with lead oxides that vary in structure when the battery charges and discharges. The material used for conducting electricity consists of dilute sulfuric acid. Industrial flood lead acid batteries may last up to 20 years. These batteries require regular maintenance, such as watering, equalizing charges and cleaning the terminals.

Deep-Charged

• The National Renewable Energy Laboratory states deep-charge lead-acid batteries offer the best option for residential solar power systems. Manufacturers developed this type of battery for off-grid solar energy systems. Deep-discharge refers to the battery's capacity to drain to a low level for a repeated number of cycles over a prolonged period. For example, a high-quality deep-cycle battery for a residential solar power system could drain 80 percent of its capacity and recycle to full charge 2100 times. This feature is important when selecting batteries for an off-grid solar power system that does not have a connection to conventional utility supply.

Gel

• Gel batteries contain acid, but manufacturers add silica gel to transform the acid into a jelly-like mass. One primary advantage of a gel-acid battery lies in the lack of a spill if a battery casing cracks or breaks open. These batteries require a slower charge rate, which prevents excess gas from harming the cells. When used in hot climates, excessive water loss can cause gel batteries to have a short life span life. Gel batteries make a good choice as backup for grid-tied solar power systems or for light discharge requirements.

Absorbent Glass Mat

• An absorbent glass mat (AGM) battery consists of a sealed unit that has a Boron-Silicate glass mat, soaked in electrolyte. AGM batteries do not contain liquid and can withstand heavy-duty use. The absence of liquid means the battery does not cause a spill when broken. The batteries do not expand or freeze in cold weather. Overall, AGM batteries have a higher quality, keep better voltage levels, have a slower rate of discharge and a longer life.

RV or Marine

• RV or marine batteries are appropriate for solar power system for boats campers and recreational vehicles. However, most batteries that come with RV will not deliver continual use over an extended period. The solar RV Panel website recommends AGM batteries. These batteries can handle jostling and the wear incurred in traveling and rugged environments. In addition, they have less of a tendency to releasing gas, if overcharged, when installed inside the RV.