The answer is that the battery needs to be activated, but this is not what the user has to do. I have visited the production plant of lithium-ion batteries. Before leaving the factory, the lithium-ion batteries go through the following process: the lithium-ion battery shell is filled with electrolyte-sealing-formation, which is constant voltage charging, and then discharging. This is done for several cycles to make The electrode is fully immersed in the electrolyte and fully activated until the capacity meets the requirements. This is the activation process-capacity division, which is to test the capacity of the battery. Select batteries of different performance (capacity) to classify, classify the battery, and perform capacity matching. The lithium-ion battery thus produced has already been activated to the user.

The nickel-cadmium batteries and nickel-metal hydride batteries that we commonly use are also released after being activated. The activation process of some of the batteries requires the battery to be in an open state, and then sealed after activation. This process can only be completed by a battery manufacturer.

There is a problem here. The battery from the battery factory is delivered to the user. This time is sometimes very long, ranging from 1 month to half a year. At this time, the battery electrode material will be passivated, so the manufacturer recommends the first use It is best to perform 3-5 full charge and discharge processes of the battery in order to eliminate the passivation of the electrode material and reach the maximum capacity.

In the three national standards for nickel-metal hydride, nickel-cadmium and lithium-ion batteries promulgated in 2001, the initial capacity of the battery has been clearly stipulated. The battery can be deep-charged and deep-released 5 times. When one time meets the regulations, the test To stop. This explains the phenomenon I said.

So called "second activation" is also possible, the user's first use of the "new" battery for as many deep charging and discharging cycles as possible.

However, according to the author's test (for lithium-ion batteries), the lithium-ion battery with a storage period of 1 to 3 months is subjected to a deep charge and deep discharge cycle treatment, and its capacity increase phenomenon is almost non-existent.