Lithium-ion (Li-Ion) has a terminal voltage of 3.6V. Chemistry: lithium cobalt oxide (LiCoO2). Used in mobile phones, laptops, cameras, etc. Available in many cell sizes and variants e.g. 18650. Charging of Li-Ion is in stages, first with constant current and then switching to constant voltage when the cell has reached 4.2 volts. Suitable charging current is 0.7-1C. Typical working voltage is 3.0 to 4.2 volts with a cutoff voltage of 2.5V. Charging and discharging faster than 1C reduces the lifetime of the cell. The main disadvantage of Li-Ion technology is that it is vulnerable to overcharging and high temperatures. Another disadvantage of Li-Ion technology is the high cost of cobalt (Li-Ion cells contain about 17% cobalt).