This Tenergy Plug-In Type Ni-MH/Ni-Cd Battery Charger (9V Block) Model T-2299 is a versatile and reliable option for charging your rechargeable batteries. It is compatible with a wide range of batteries, including AA, AAA, C, and D 9V batteries, and has a capacity of 230mAh. This charger is ideal for use with smoke alarms and other precision devices that require low drain batteries. The chemical composition of this charger is NiMH, and it is designed to be a rechargeable battery type. With its multipurpose application, this charger is a must-have for any consumer electronics enthusiast. It is easy to use and comes with a range of features that make it an excellent choice for charging your batteries.