These Smart Garden replacement rechargeable solar light batteries are AA sized with a 600mAh capacity and come in a pack of 4. They are designed with a lower power rating suitable for solar lights, accommodating the repeated on/off cycles they experience for a longer lifespan. Ni-MH (Nickel Metal Hydride) technology is used, which is superior to older Ni-Cd technology. It's important to check your old device's batteries for voltage and mAh ratings to ensure you purchase the correct replacements. These batteries are suitable for solar lights as they recharge daily and use small amounts of power for LED operation.