Lead Acid batteries are the most common batteries used for energy storage in either off-grid or grid-tie systems. The three main lead acid battery technology are Flooded, AGM and Gel.
Flooded lead acid battery is the traditional technology, unsealed with liquid electrolyte. They are unsealed and therefore have to be kept upright in a vented area and insulated. It is the cheaper option.
The technology VRLA (valve-regulated lead-acid) battery are non spillable, deep cycle, free maintenance and can be mounted in any position, since the valves only operate on overpressure faults. They are also safer for the environment, and safer to use. VRLA batteries are low self discharge. Two main types of VRLA batteries are AGM and Gel.
AGM (Absorbed Glass Matt) battery is a type of valve-regulated lead-acid battery (VRLA) feature fiberglass mesh between the battery plates which serves to contain the electrolyte. AGM up to 5 times faster charge than with Flooded technology. AGM is preferred when a high burst of amps may be required.
Gel (VRLA) battery is add silica dust to the electrolyte, forming a thick putty-like gel between the plates. The viscous electrolyte prevents the cell from leaking when damaged. Gel batteries excels in slow discharge rates and slightly higher ambient operating temperatures. The charging voltage must be limited to a very precise range or the battery will suffer premature failure. It is the expensive option.
To sum up, flooded batteries might be good for lower installation cost but they need a correct maintenance. AGM batteries are the best if you are interested in a maintenance free storage system after the installation. Gel batteries are recommended for higher ambient temperatures but you need to be careful with their charge profile.
You can find more information about Flooded, AGM and Gel batteries in Rekoser’s website. If you are unsure which battery is best for your application, please email our us for help making the correct decision.