1. Electric forklift truck batteries can be installed and used in time when they arrive outside the factory, resulting in long-term storage. Long-term storage will inevitably lead to self-discharging, which will lead to capacity shortage. Because long-term storage of batteries is incorrect, it is necessary to charge the batteries once every other time.

　　2. Corrosion of positive plate of forklift battery results in insufficient capacity due to deformation.

　　The positive plate of forklift battery is the main factor affecting the working life of the battery. The capacity of battery charge-discharge cycle of electric forklift truck, especially the capacity decline under deep cycling, is closely related to the quality deviation of positive plate.

　　3. Softening and shedding of active material on positive grid

　　Microscopically, there are macropore and micropore in the active substance. The size of macropore is more than 0.5 cm. It is composed of many small pore. With the discharge cycle going on, the surface of the active substance shrinks, forming core and coral-like structure. The aggregation of small pore in multiple discharge cycles increases, which makes the macropore increase continuously, destroys the positive structure and causes the active substance to fall off.

　　The main reason for these problems is the high current charging and discharging of forklift battery. In order to avoid the occurrence, the current of charge and discharge should be guaranteed and the phenomenon of over-charge or over-discharge should be avoided.

　　4. Corrosion deformation of positive grid

　　The corrosion rate of the grid depends on the composition of the alloy, but the higher the storage temperature, the faster the corrosion rate, the deeper the discharge depth and the more serious the corrosion.