Solar batteries, also known as solar energy storage systems or solar storage batteries, come in various classifications based on their chemistry and design.

1. Lead-Acid Batteries:
   • Flooded Lead-Acid Batteries: These are the traditional, less expensive lead-acid batteries with liquid electrolyte (sulfuric acid and water). They require regular maintenance and have a shorter lifespan.
   • Sealed Lead-Acid Batteries (SLA): Sealed lead-acid batteries are maintenance-free and are commonly used for smaller-scale solar energy storage.
2. Lithium-Ion Batteries:
   • LiFePO4 (Lithium Iron Phosphate): These batteries are known for their long cycle life, high energy density, and safety. They are commonly used in residential and commercial solar storage systems.
   • NMC (Lithium Nickel Manganese Cobalt Oxide): NMC batteries offer a good balance between energy density and cycle life, making them suitable for a wide range of applications.
   • NCA (Lithium Nickel Cobalt Aluminum Oxide): NCA batteries have a high energy density and are used in some high-end solar storage solutions.
   • LFP (Lithium Ferrous Phosphate): LFP batteries are known for their safety and long cycle life. They are often used in residential and commercial energy storage systems.
3. Flow Batteries:
   • Flow batteries use liquid electrolytes stored in external tanks and are known for their scalability and long cycle life. Vanadium redox flow batteries are a common type used in solar energy storage.
4. Sodium-Based Batteries:
   • Sodium-ion batteries are a potential alternative to lithium-ion batteries. They are still in the early stages of development but offer advantages in terms of cost and resource availability.
5. Hybrid Batteries:
   • Some batteries combine multiple chemistries to achieve a balance of performance and cost. For example, a lithium-titanate battery can be combined with a lithium-ion battery to provide fast charging and high energy density.
6. Nickel-Cadmium Batteries (Ni-Cd):
   • Nickel-cadmium batteries were once commonly used but are less prevalent today due to environmental concerns associated with cadmium. They still find use in some specialized applications.
7. Advanced and Emerging Technologies:
   • Various emerging battery technologies, such as solid-state batteries, lithium-sulfur batteries, and others, are being researched and developed for solar energy storage. These technologies aim to provide higher energy density, longer cycle life, and improved safety.
8. Saltwater Batteries:
   • Saltwater batteries, also known as saline or aqueous batteries, use a saltwater electrolyte and are considered safer and more environmentally friendly. They are used in some residential solar storage systems.

Each type of solar battery has its own advantages and disadvantages, including factors like cost, cycle life, energy density, safety, and environmental impact. The choice of a solar battery should consider these factors, as well as the specific requirements of the solar energy system and the user’s energy storage needs.