Online shopping. It is sold on many online platforms. Including factory direct sales. Or the battery meter at your local electrical mall. 3If the quantity is large, you can order from the manufacturer. 18650 is the creator of lithium-ion batteries - a standard lithium-ion battery model defined by the Japanese company SONY in order to reduce costs. 18 means the diameter is 18mm, 65 means the length is 65mm and 0 means. Cylindrical battery.
Type Differences
Lithium batteries are labeled 3.7V or 4.2V. It's just that the manufacturer's labeling is different. 3.7V refers to the platform voltage (i.e. typical voltage) of battery discharge during use, while 4.2V refers to the voltage when it is fully charged.
Common rechargeable 18650 lithium batteries have a voltagestandard 3.6 or 3.7 V. When fully charged it is 4.2 V. This has little to do with the power (capacity) of 18650 batteries. from 1800mAh to 2600mAh (the capacity of 18650 battery is mainly 2200~2600mAh), the main capacity even has a capacity of 3500 or 4000mAh or more.
Add a discharge resistor outside the 18650 battery and discharge the 18650 battery alone. If the discharge voltage is less than 2.0V and it still discharges, it means the battery itself has no resistance. protection shield. If there is a protective plate, the discharge voltage is normal. Remember to use a voltmeter to check the voltage of the 18650 battery from time to time during the discharging process to avoid over-discharging the 18650 to 0V. Over-discharging to 0V would cause great damage to the lithium battery and even damage it.
Certaines 18650 still have protective plates.