Maha PowerEx MH-C401FS4AA27 - Battery charger - battery - rechargeable - AA x 4 - 2700 mAh Charge AA / AAA NiMH or NiCD batteries in 100 Minutes Accurately and Coolly Unique FLEX negative pulse charging algorithm allow the battery to accept a more complete charge The new FLEX negative pulse algorithm also significantly enhances battery life. Manually Switch between 100 minute fast charge and 5 hour gentle charge The MH-C401FS is the first charger on the market to offer the choice between a 100-minute rapid charge and a slower, gentler 5-hour charge Four Independent Charging Circuits Limited Lifetime Warranty