Maintenance method of lithium-ion battery pack
　　Lithium battery core overcharge to voltage is higher than 4.2 V, will start to produce side effects. Of charging the higher the pressure, the higher the risk also follow. Lithium battery core electric pressure is higher than 4.2 V, the anode materials within less than half the number of lithium atoms left, store usually break down at this time, let the battery capacity to produce permanent decline. If continue to charge, due to the storage of the cathode has been full of lithium atoms, subsequent anode materials of lithium metal accumulation in the surface. These lithium atoms from lithium ion to the cathode surface to grow in the direction of the dendritic crystal. The lithium metal crystal through the diaphragm paper makes is negative short circuit. Sometimes in short circuit batteries before the first explosion, this is because in the process of overcharge, electrolyte materials can produce gas cracking, such as making the battery shell or blow up pressure valve is broken, and let oxygen in and accumulation in the lithium atoms on the surface of the cathode reaction, then exploded. Therefore, lithium batteries, be sure to set the upper limit of voltage, can simultaneously to the battery life, capacity, and security. The ideal maximum charging voltage of 4.2 V.
　　Lithium battery core discharge voltage will be lower limit. When the batteries voltage below 2.4 V, part of the material will begin to be destroyed. And because the battery self-discharge, put the more the longer the voltage is low, therefore, discharge when had better not to 2.4 V. Lithium battery discharge from 3.0 V to 3.0 V during this period, the release of energy accounted for only about 3% of the battery capacity. Therefore, is an ideal discharge cut-off voltage of 3.0 V.
　　Charge and discharge, in addition to the limit of voltage and current limits can also be necessary. When the current is too large, lithium ions to enter the store, would gather in the material surface. After these lithium ion for electronic, can produce lithium atoms in the material surface crystallization, this has to do with the overcharge, will cause the risk. One thousand battery shell is broken, and would explode. Therefore, the protection of lithium ion batteries, to include at least: charging voltage upper limit, lower limit discharge voltage, and current limit. Generally lithium battery pack, in addition to the lithium battery core, there will be a piece of protection plate, the main protection board is to provide the three protection. Protection board, however, these three protection is obviously not enough, lithium battery explosion or disengaged from around the world. To ensure the safety of the battery system, the battery must be the cause of the explosion.