Nickel-metal hydride battery
A nickel-metal hydride battery, also known as NiMH, is a secondary cell, meaning it is a rechargeable battery. They are used in cameras and other electronic devices. They are made in several sizes; AA is the most common. They are similar to nickel-cadmium batteries but store twice as much energy. They have a voltage of 1.2 V, the same as the nickel-cadmium battery. They do not contain toxic chemicals like the nickel cadmium battery does. They work by the oxidation of hydrides, such as lanthanum hydride, by nickel(III) oxide.
They have longer shelf life and are more durable than the lithium-ion battery. They are not as powerful for their size, although the best Ni-MH batteries are very close. They used to be more expensive than nickel cadmium batteries, but in the 21st century the cost is similar.
Nickel-metal Hydride Battery Media
Disassembled NiMH AA battery: Template:Ordered list*
Graph of NiMH cell voltage versus percent charge, for charging durations of one, three and ten hours.
NiMH cell that popped its cap due to failed safety valve
High-power Ni–MH battery of Toyota NHW20 Prius, Japan
Nickel metal hydride 24 V battery pack made by VARTA, Museum Autovision, Altlussheim, Germany
GM Ovonic NiMH Battery Module
