Bosch introduces its newest Best Built power tool battery technology, the BAT621 5.0 Ah 18V Lithium-ion FatPack battery. According to the company, the product is “the lightest and most compact FatPack style battery on the market, with the longest runtime,” and features patented CoolPack technology for longer recharge life.

Compatible with the complete line of Bosch 18V Lithium-ion power tools, the Bosch BAT621 is built with high-capacity, low-resistant lithium-ion cells which are designed to increase the overall capacity from current 4.0 Ah batteries by 25 percent. The Best Built CoolPack heat conductive housing is designed specifically to cool internal pack temperatures for longer recharge life.

According to the company the BAT621 offers an identical weight and size footprint of the previous Bosch 4.0 Ah and 3.0 Ah 18V batteries. The pack comes standard with a fuel gauge.

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