Battery energy storage is becoming a more and more popular additional device in solar energy system. The two most common types of battery chemistry are lithium ion batteries and lead-acid batteries. As the name suggests, lithium-ion batteries are made of metal lithium, while lead-acid batteries are made of lead.

With different chemical properties, the performance and cost are also different. Although both lithium-ion and lead-acid battery options are effective storage solutions, the following are their comparisons in key categories: