The lithium battery IC (overvoltage protection board is mainly composed of maintenance maintenance) and MOS tube (over-current maintenance), is used to protect lithium battery safety equipment Lithium battery with large discharge current, low resistance, long life, no memory effect, such as widely used by people, lithium ion batteries in the use of banned overcharge, over discharge, short circuit, otherwise will make battery fire and blast killed defects, so the use of rechargeable lithium batteries have a maintenance board to protect the safety of the batteries.