Lithium batteries differ from other battery chemistries due to their high energy density and low cost per cycle. However, "lithium battery" is an ambiguous term. Lithium batteries have six common chemicals that have their unique advantages and disadvantages. For renewable energy applications, the main chemical is lithium iron phosphate (LiFePO4). The chemical has excellent safety, good thermal stability, high current rating, long cycle life and abuse resistance.

Lithium iron phosphate (LiFePO4) is an extremely stable lithium chemical compared to almost all other lithium chemicals. The battery is assembled with a naturally safe cathode material (iron phosphate). Compared to other lithium chemistries, iron phosphate promotes strong molecular bonds that can withstand extreme charging conditions, extend cycle life, and maintain chemical integrity over multiple cycles. This makes these batteries excellent in thermal stability, long cycle life and abuse resistance. LiFePO4 batteries are not easy to overheat and are not "thermally out of control", so they will not overheat or ignite under strict misuse or harsh environmental conditions.

Unlike submerged lead acid and other battery chemistries, lithium batteries do not emit dangerous gases such as hydrogen and oxygen. There is also no risk of exposure to corrosive electrolytes such as sulfuric acid or potassium hydroxide. In most cases, these batteries can be stored in tight areas without the risk of explosion, and a well-designed system does not require active cooling or ventilation.