Lithium ion batteries provide the highest energy density, have no "memory effect", have a wide operating temperature range, great charge retention, initial high cost, high service life, and are rated non-hazardous for air transportation and disposal. The cells come in various cylindrical and prismatic sizes. Lithium ion cells are 3.6-3.7 volts (nominal) and range between 500 to 5,000 mAh in capacity. They can be used for fairly high discharge currents. The energy density by weight is 105-130 Wh/kg and by volume is 270-325 Wh/litre. These cells have a cycle life of over 500 cycles and discharge at about 10% per month. The operational temperature range is from -20 degrees C to +60 degrees C.

Common applications for the lithium ion batteries are pagers, cellular phones, camcorders, computers, and medical equipment.