Nickel-cadmium, nickel-metal hydride and lithium-ion rechargeable batteries are widely used in various portable electrical devices (such as laptops, video cameras and mobile phones), and each rechargeable battery has its own unique chemical properties.
The main difference between nickel-cadmium and nickel-metal hydride batteries is that nickel-metal hydride batteries have higher energy density. Compared with the same type of battery, the nickel-metal hydride battery capacity is twice that of the nickel-metal battery.
This means that the battery can be used for much longer periods of time without adding extra weight to electrical equipment. Another advantage of nimH batteries; A greatly reduces the "memory effect" problem in the cell, so that the nimH cell can be used more conveniently. Nickel-metal hydride batteries are more environmentally friendly than nickel-metal batteries because they contain no toxic heavy metals.
Li-ion is also fast becoming the standard power source for portable devices, providing the same amount of power as nickel metal hydride batteries but with about 35 percent less weight, which is critical for devices like video cameras and laptop computers. Li-ion's complete lack of "memory effect" and lack of toxins are also important factors that make it a standard power source.
The discharge efficiency of nickel-metal hydride battery will decrease significantly at low temperature, and the general charging efficiency will increase with the increase of temperature, but when the temperature rises above 45℃, the performance of rechargeable battery material will degrade at high temperature, and the cycle life of the battery will be greatly shortened.