Smart Garden Replacement Rechargeable Solar Light Batteries 1/3 AAA 80mAh 4 PackPLEASE NOTE that 2/3AA and 2/3AAA and 1/3AAA is not the same as AA or AAA they are "two thirds" or "one third" the size of the either AA or AAA and is a different type of smaller battery.PLEASE CHECK YOUR EXISTING BATTERIES IF YOU NEED the 2/3 or 1/3 type batteries your old batteries will be clearly marked as 2/3AA or 2/3AAA or 1/3AAA. Can be used in any device accepting 1/3 AAA batteries but you need to match the mAh rating to the correct batteries for your device in order to see correct performance or operation of your equipment.150mAh - 600mAH Batteries are suitable for solar lights because the solar lights automatically recharge every day and only use small amount of power to burn a small LED. Ni-MH stands for Nickel Metal Hydride and is the chemical substance inside the battery which creates the electricity. Ni-MH batteries are far superior to Ni-Cd batteries as Ni-Cd is older technology and the batteries do not survive for the same number of charge and discharge cycles as Ni-MH do.PLEASE CHECK YOUR OLD DEVICE BATTERIES, PARTICULARLY THE VOLTAGE AND mAh RATINGS AND CONFIRM THAT YOU ARE PURCHASING THE CORRECT REPLACEMENT BATTERIES FOR YOUR DEVICE.