Panasonic Eneloop Pro 2550 mAH (was Sanyo 2500XX) AA Batteries - Sixteen Batteries with Free Battery Holders Sixteen 2550 mAh low discharge batteries and four 4 cell battery holders Pre-charged and ready for immediate use Can be recharged up to 500 times with no memory effect - a full charge every time Provide high performance in sub-zero temperatures to -4 degrees Farenheit Batteries maintain 75% of charge after 1 year of non-use