Blog - Chargers and charging

QUESTION: Are the lithium cells charged before shipping to the customer?

ANSWER: No. The cells are not charged. They are shipped in the same condition as received from the factory. The cells are shipped with 50% and less energy left in them. The cells must be charged to full and balanced (equilibrated) by the customer before the installation of the battery pack.

For safety reasons it is forbidden to transport the batteries that are fully charged. In case of an accident the fully charged cells would release all energy and could cause serious damage. The less energy is left in the cells during transportation, the safer the transportation is.

During the manufacturing process, the initial charge is made at the factory. Following this initialization charge, the introductory charge and discharge cycles may be performed at the factory to verify the cells specification, capacity and internal resistance. After these test cycles the battery is usually left at 50% capacity, ready for the shipping.

This capacity is sufficient for the 12 to 15 months of the storage. Since the self-discharge rate is bellow 3%, the cell will not discharge by itself, and it stays in a perfect condition all the time. (Additionally if the cells should have some internal problem, the cell would get self-discharged to empty condition during the period of storage)

If the cells are to be stored for one year or more, we recommend to make the full balancing charging before the storage of the cells. The charging should be repeated once in 12 to 15 months.

Prior to installation of the battery pack, the cells must be individually charged to the full voltage level as specified by the manufacturer.  This will make the battery pack consistent and fully balanced (equilibrated).

See also the cell charging FAQ.