This Duracell Ion Speed 4000 NiMH Battery Charger offers amazingly fast charge times of 1 to 2.5 hours (To approx. 85% of full charge when using 1300mAh up to 2500mAh 2xAA NiMH Batteries) with 4000 mW of charging power. It recharges any rechargeable AA and AAA NiMH battery from any brand. You can recharge two or four batteries at a time and, with the LED Charge Status Indicator, you’ll know when charging is complete. It also features an Auto Shutoff so you won’t use any unnecessary electricity. It even has a bad-battery indicator along with nine smart safety features. Plus, the Duracell Rechargeable Pre-Charged NiMH batteries are guaranteed to last 10 years or 400 recharges, whichever comes first. Battery Type: NiMH; Battery Size: AA; AAA; Charge Time: 1 to 2.5 h.