DieHard Rechargeable Nickle Metal Hydride Batteries now come in AA and AAA with convenient AC charges to optimize the use of these exceptional batteries. DieHard is an iconic American brand and is amongst the top 6% of most trustworthy brands in the United States. DieHard brand power has been ANSI tested by independent labs and has proven to provide superior performance across all cell types, from general purpose to the most demanding high drain applications.