SmarToools RB40 AA 1.5V 2600mWh USB Type-C Rechargeable Li-ion Battery (Sold as a 4-Cell Pack)

The SmarToools RB40 is a rechargeable AA battery that charges through its own USB Type-C port, sold here as a 4-cell pack. Unlike ordinary NiMH rechargeables, which sit at 1.2V, it holds a constant 1.5V output through an internal converter, so it behaves like a fresh alkaline cell in equipment that expects full alkaline voltage: remotes, wireless mice and keyboards, wall clocks, torches, toys and small instruments. Each cell is lithium-ion, rated at 2600mWh, and charges directly through the Type-C port on the cell itself from a 5V input, so there is no charger cradle to buy, store or lose. A full charge takes about 2 hours from empty, and an LED indicator shows charge status while it runs. Protection circuitry guards against short circuit, overcharge, over-discharge and overflow, and the cells are rated for up to 1200 recharge cycles, so one pack stands in for a great many disposable batteries over its life. For a household that works steadily through AA cells across a television remote, a wall clock, a wireless keyboard and a child's toy, recharging a set costs nothing beyond the electricity and removes the errand each time something dies. Keeping charged cells aside is also sensible for a torch when the power goes. Charge all four before first use and rotate them as they run down.