Really, these batteries provide seemingly endless power. They hold their charge for weeks with very little loss. I can use one battery for drilling and driving throughout an entire (moderately sized) project. They are extremely lightweight and charge in twenty minutes or less usually (in hot weather it takes longer).
All three of mine slide on and off easily, with no issues of binding or falling off. With all the praise comes a VERY important caveat. DO NOT run these batteries into the ground.
The instructions state that as soon as you notice a loss of power, stop and charge. If you over-discharge Li-Ion batteries, you can seriously degrade the life of the battery. These batteries are 1/3 cheaper on Amazon.com than at the home centers, so buy from here! Also, only the cells themselves are made in Japan, all other parts are made and final assembly is in China.
The Makita 18-volt LXT battery produces 280-percent more lifetime work with 2-times more cycles. Charging at any time will have no effect on the battery and a self-discharge keeps battery cells active and ready for use. It has a better fit and a longer run time (280 percent longer runtimes). Buy $69 Makita BL1830 18-Volt LXT Lithium-Ion Battery