Solar batteries come in four main types. The batteries are an important component of solar system. They store electricity for later use. We have summarised the four main types of solar batteries that can be used in power systems.
1) Lead acid
Boring perhaps. Ugly and bulky definitely. But also dependable, tried and tested. Lead acid batteries have been taking Aussies off-grid for decades. But they are rapidly being eclipsed by other technologies with longer warranties and lower pricing as solar battery storage becomes more popular. These batteries require maintenance just like unsealed Car batteries. Don't let that fool you. Lead acid batteries remain quite effective and cheap.
Lithium-ion (Li-ion) batteries are quite popular these days. They are being used in electric cars and this aiding their development. Today there are number of Li-ion batteries being used in homes, such as the popular Pylontech Li-ion batteries. Due to the fact that Li-ion battery technology is fairly new, batteries are still quite expensive but last for 10 years.
3) Gel Batteries
The gel batteries are virtually maintenance free as they use one-way open valves that allow the internal gasses to recombine into water, hence removing any need to check to top up distilled water or monitor water level. Strictly speaking gel batteries are just Lead-Acid batteries but with a more advanced mechanism of combining the chemistry that is more robust and user friendly. Gel batteries are non spill and don't need distilled water to be topped up every 2 to three months like the Lead-Acid counterpart.
AGM batteries differ from flooded lead acid batteries in that the electrolyte is held in the glass mats, as opposed to freely flooding the plates. Very thin glass fibers are woven into a mat to increase the surface area enough to hold a sufficient amount of electrolyte on the cells for their lifetime.
If you want to know more about battery technology read this good article on Gel and AGM batteries.