BOSCH 18 Volt Lithium-Ion Cool Pack Battery, 1 x 4.0Ah Batteries

The Bosch 18 volt 4.0Ah Lithium-ion CoolPack battery has unique CoolPack technology that uses a passive cell cooling system. Passive cell cooling allows for better performance and a greatly improved run time, so you only need to stop when the job is done. The interchangeable battery is compatible with any 18-volt Bosch Lithium-ion power tool, allowing for added flexibility while you work.
Features:
Extremely robust: Fully functional even after a 3 metre drop onto concrete
Cool pack technology for up to 100 percent longer lifetime (cf. battery without Coolpack)
Bosch Flexible power system – battery suitable for all tools in one voltage class
No self-discharge, no memory effect
Superb runtime and up to 65 percent more runtime than 3.0Ah batteries
Optimal protection of the cells
Battery 100 percent compatible with all tools within its voltage class
Fuel gauge – indicator showing remaining battery life
Robust housing which can survive a 3-metre drop 
Lightweight and compact
Long life due to CoolPack technology
Special heat dissipating at the base of the pack protects cells inside from overheating
Specifications: Battery Capacity: 4.0Ah
Battery Type: Lithium-ion
Battery Voltage: 18 volt
Length: 115 mm
Height: 56 mm
Width: 74 mm
Weight: 0.6 kg