Get more power and runtime for your tools with the AEG 18V 4.0Ah FORCE Battery Twin Pack. The two batteries feature the new compact bucket design, making them 23% smaller and 10% lighter than previous generations. Smart electronics in this battery provides overheating and over-current protection so you can push your tools harder. A built-in fuel gauge makes it fast and simple to check how much charge is left without using a battery charger.