21700 3.7V 4000mah Lithium Ion battery Cell

21700 is a model of lithium ion battery, 21 stand for the diameter is 21mm, 70 stand for the length is 70 mm, 0 stands for cylindrical battery, 21700 battery has a high energy density,the performance of this battery is very good during the work and it is widely used in electronic field.

  • 21700 3.7V 4000mah Lithium Ion battery Cell


    High-grade flashlight, portable power source, wireless data transmission device, electric thermal clothing, shoes, portable instruments and meters, portable lighting, portable printers, medical instrument, Electric Car etc.


    — Working voltage :2.4~4.2V.
    — Nominal capacity :4000mAh.
    — Max discharge current: 5C.
    — Working temperature: charging: 0 ~ 45 ℃
    — discharge: - 20 ~ 60 ℃


    1. Do not immerse the battery in water or allow it.
    2. Do not use or store the battery near sources of heat such as a fire or heater.
    3. Do not use any chargers other than those recommended.
    4. Do not reverse the positive(+) and negative(-) terminals.
    5. Do not connect the battery directly to wall outlets or car cigarette-lighter sockets.
    6. Do not put the battery into a fire or apply direct heat to it.
    7. Do not short-circuit the battery by connecting wires or other metal objects to the positive(+) and negative(-) terminals.