Consistent 1.5V and 3.25 hour charging time are game changing. Stop buying single-use batteries and get a modern solution. Designed for performance convenience and reliability, our D batteries will help you reduce waste and save money and time. Fast Charging Lithium Battery 1000+ Charge Cycles  Convenient USB Charge Port Just plug any USB-C or micro USB cable or use the included cable to charge four batteries at once. Built-In LED Charging Indicator Paleblue Batteries let you know when they are fully charged. On-Board Smart Technology Provides Safe Charging No more batteries ruining expensive electronic devices!