Sega Master System / Mark III / Game Gear
The biggest advantage to the Power Back was that it could screw on to the Game Gear for full time use. Although it screws on to the back of the Game Gear, it is not actually connected until you plug it into the power jack at the top of the Game Gear. It was criticized for adding more weight and size to the Game Gear, which itself was criticized for not being portable enough to be a portable console. When it was new, the Power Back could average about 8 hours of play, compared to 5 or 6 hours with alkaline batteries. The Power Back was released late into the unit's life time and was not released in Europe.