Efest Purple IMR 18650 3500mAh 3.7V Li-ion High-current cell 

Product detailsEfest Purple IMR 18650 3500mAh 3.6V - 3.7V Li-Ion Cell (Flat Top)
Li-Ion battery with a discharge current of up to 20A pulse and 3500mAh capacity
Suitable for rechargeable batteries, with sufficient capacity.

• Capacity 3500mAh
• Min. Capacity. 3350mAh
• Rated voltage 3.6 - 3.7V
• Charging voltage 4.20V ? 0.03
• Discharge voltage 2.5V
• Discharge current constant 10A
• Discharge current pulse 20A
• Positive pole flat (FlatTop)
• Protection circuit (BMS) no (unprotected)
• Diameter 18.50mm ? 0.2
• Height 65.2mm ? 0.2
• Weight 48g ? 1
• Charging method CC-CV
• Manufacturer Efestpower

For the charging of lithium-ion batteries, a special charger is required, which charges the batteries according to a special charging procedure. (CCCV = constand current, constant voltage.) The batteries must not be charged via a voltage of 4.35 volts, as there is a risk of fire or explosion. It is advantageous to charge the batteries only up to approx. 4.2 volts, since this significantly increases the service life or number of charging cycles (possibly up to a doubling). Only lithium ion chargers may be used for charging. However, the cheap chargers sometimes have the disadvantage that they do not switch off safely after the end of the charging process, but the rechargeable batteries with a small charging current, which can be dangerous. Batteries and batteries are not included in household waste! Please dispose of these as prescribed by law in the municipal collection points or in the intended [mostly green] containers of the trade.

Note: Lithium cells may only be operated with protective electronics!

Safety instructions:
Please note that lithium cells may only be used by qualified persons.
Incorrect handling or short-circuiting can lead to fire development or explosion.

Other features:

Lithium-ion batteries are thermally stable and are not subject to any memory effect.
They are based on lithium and have a high energy density.