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   Nickel metal hydride batteries are hydrogen ions and the metal nickel composite power reserves more than 30% of the nickel cadmium battery, more light than nickel-cadmium batteries, longer service life, and to the environment pollution-free, no memory effect. The disadvantage is that the price of nimh batteries are much expensive nickel cadmium battery, performance is worse than lithium battery.

   Class of lithium battery was invented by Edison by lithium metal or lithium alloy as the cathode material, the use of water battery electrolyte solution. Battery using the reaction equation is as follows: Li + MnO2 = LiMnO2 for the REDOX reaction, the reaction of discharge. In the past, because the chemical nature very lively, lithium metal for the processing, storage, use and the environmental requirement is very high, so the lithium battery has not been applied for a long time. With the development of modern science and lithium battery has now become the mainstream. Rechargeable lithium-ion batteries due to its relatively common nickel cadmium/ni-mh battery has a (relatively) small size, light weight, low self-discharge rate, no memory effect, the advantages of widely used in many new mobile device. We usually use mobile phones, notebook computers, mobile devices such as PDA batteries has been gradually replaced by lithium batteries. Nickel metal hydride battery memory effect is not very  obvious, a bit, to be urgent need, I don‘t have to electric light after filling, use at ordinary times is best is after the light enough.

   Lithium battery is greater than the energy of battery cabinet; A single lithium battery voltage is 3 times of the nimh batteries; No memory effect, can be in charge. But also can‘t use the charger, such amounts of charge and discharge, will affect the battery life. Lithium battery should not be stored for a long time, time is long will permanently lose capacity. It is best to charge 40%, after put in a refrigerator for refrigerated box. Lithium battery charging requirements and nickel cadmium/nickel metal hydride batteries, lithium rechargeable battery monomer voltage of 3.6 V (3.7 V) some battery block may be nominal. As the battery is full, the lithium battery voltage will gradually rise, this is also a sign of whether lithium batteries full of, general manufacturers recommend suspending charging voltage of 4.2 V (in the case of single section lithium battery). Commonly used for lithium battery charging pressure limiting current limit method, if a friend wants independence for lithium battery, need to pay attention to its charging method and nickel cadmium or nickel metal hydride batteries used by constant current charging method is different, can‘t use normal/nickel metal hydride rechargeable nickel cadmium battery charger.