Batteries are everywhere—remotes, headlamps, toys, wireless mics, torches. And for a long time, single-use batteries have been the default. You use them, bin them, replace them. But that convenience comes at a steep cost. As...

Lithium-ion and nickel metal hydride (NiMH) are two of the most popular technologies for consumer batteries. Before lithium-ion was popular, NiMH competed with NiCad batteries for market dominance. But these days, lithium-ion is the clear winner. It...