Windyfire 18650 2000mAh (Green)



Official specifications:

• Brand/model: Windyfire
• Type of Battery: IMR 18650/2000mAh
• Size(mm): 18mm(Diameter) x 65mm(Length)
• Positive Shape: Button top
• Weight(g): 42±2g
• Nominal Voltage: 3.7V
• Nominal Capacity: 2030mah(0.2 C Discharge)
• Mininum Capacity: 2000mah(0.2 C Discharge)
• Discharge Cut-off voltage: 3 V
• Standard Charge: 0.4 A /4.2V
• Maximum charge current: 2A
• Quick Discharge Current: 4A
• Max Discharge Current: 10A
• Initial Impedance: Max:40mOhm
• Cycle Life: 310times: discharging capacity>85%, 510times: discharging capacity>60%
• Temperature Characteristics: -10°C/0.2C >80% Capacity; 20°C/0.2C =100% Capacity;60°C/0.2C >95% Capacity
• Charging Time: Standard charge : 5-7hours, Rapid charge : 2-3hours
• Operating environment: Charging, 0°C ~ 45°C ; 65±20%RH, Discharging, -20°C~60°C ; 65±20%RH
• Storage environment: Temp(-20°c -35°c) / Relative humidity (45-75%)

A fairly low capacity cell without any high current ability.










The cell does very good up to 7A, the curves are tracking nicely and with nearly constant capacity. This is a very good result for a 4A rated cell.















Conclusion

The cell looks to be of good quality, but the capacity is fairly low for todays batteries. If the price is low, this cell will be interesting.
This cell gets an acceptable rating.



Notes and links

The batteries was supplied by Windyfire for review.

How is the test done and how to read the charts
How is a protected LiIon battery constructed
More about button top and flat top batteries
Compare to 18650 and other batteries