OLIGHT Omni-DOK Universal Charger and Rechargeable 18650 Batteries for Flashlight Camera Rechargeable lithium battery with 3.6v or 3.7v of nominal voltage: 18650, 17670, 16340, 14500. Rechargeable NiMH batteries: AA, AAA Four-hour charge time for 18650s; Ability to simultaneously and safely charge different types of batteries Overcharge protection stops charging when a cell has reached a full charge Three-blink notification of improper installation, unsupported batteries, or a shortage