Here are some common types of batteries used in combination with solar panels:

1. Lead-acid batteries: These are the most traditional and widely available batteries. They are relatively affordable and can be a good option for small-scale solar energy systems. However, lead-acid batteries are heavy, have limited lifespan and capacity, and require regular maintenance.

2. Lithium-ion batteries: Lithium-ion batteries have become popular due to their high energy density, longer lifespan, and lightweight design. They are more expensive than lead-acid batteries but offer higher efficiency and greater storage capacity. Lithium-ion batteries are available in various types, such as lithium iron phosphate (LiFePO4) and lithium nickel manganese cobalt (NMC).

3. Flow batteries: Flow batteries are batteries where the electrolytic fluid is stored in external tanks. They offer the ability to adjust storage capacity by simply increasing or decreasing the size of the tanks. Flow batteries have a long lifespan and can offer high cyclical stability, but they are currently more expensive and less widely spread than other types of batteries.

Choosing the right battery for your solar panel system depends on several factors, including the desired storage capacity, lifespan, efficiency, available budget, and any specific requirements. It is recommended to contact a professional solar energy system installer to get advice tailored to your specific situation and needs. They can help you choose the most suitable battery for your solar energy system.