Panasonic BK-3HCCA12FA eneloop Pro AA High Capacity Ni-MH Pre-Charged Rechargeable Batteries, 12 PackPanasonic eneloop Pro high capacity Ni-MH “low Self discharge” batteries utilize Panasonic's advanced rechargeable battery technology providing up to 2550mAh (AA batteries)/ 950mAh (AAA) of power and the ability to be recharged up to 500 times. eneloop Pro battery cells deliver consistent power performance, maintain 85% of their charge for up to one year, come pre-charged by solar power (at the factory) and are ready to use out of the package. These eneloop cells also have increased power, added storage life and extreme temperature performance down to -4 degrees Fahrenheit.Panasonic BK-4HCCA4BA eneloop pro AAA High Capacity Ni-MH Pre-Charged Rechargeable Batteries, 4 PackPanasonic BK-4HCCA4BA Eneloop Pro high capacity Ni-MH “low Self discharge” batteries utilize Panasonic's advanced rechargeable battery technology providing up to 2550mAh (AA batteries)/ 950mAh (AAA) of power and the ability to be recharged up to 500 times. Eneloop Pro battery cells deliver consistent power performance, maintain 85% of their charge for up to one year, come pre-charged by solar power (at the factory) and are ready to use out of the package. These Eneloop cells also have increased power, added storage life and extreme temperature performance down to -4 degrees Fahrenheit.