Ni-MH batteries are divided into high-voltage Ni-MH batteries and low-voltage Ni-MH batteries.

Low-voltage nickel-metal hydride batteries have the following characteristics: (1) The battery voltage is 1.2~1.3V, which is equivalent to that of nickel-cadmium batteries; (2) The energy density is high, which is more than 1.5 times that of nickel-cadmium batteries; Good performance; (4) can be sealed, strong ability to withstand overcharge and discharge; (5) no dendrite formation, can prevent short circuit in the battery; (6) safe and reliable, no pollution to the environment, no memory effect, etc. 

High-voltage Ni-MH batteries have the following characteristics: (1) High reliability. It has good over-discharge and over-charge protection, can withstand high charge-discharge rate and has no dendrite formation. Has good ratio characteristics. Its mass-specific capacity is 60A·h/kg, which is 5 times that of nickel-cadmium batteries. (2) Long cycle life, up to thousands of times. (3) Compared with nickel-cadmium batteries, it is fully sealed and requires less maintenance. (4) The low temperature performance is excellent, and the capacity does not change significantly at -10°C.