UltraFire SZ18650 9900mAh (Yellow)

DSC_3684

Official specifications:
UltraFire%20SZ18650%209900mAh%20(Yellow)-info

The latest battery scam from China.

DSC_3683

DSC_3685 DSC_3686

DSC_3687
DSC_3688
DSC_3689

UltraFire%20SZ18650%209900mAh%20(Yellow)-Capacity

I tried 3 cells, there were surprisingly well matches, but below* rated capacity and not able to deliver much current.

UltraFire%20SZ18650%209900mAh%20(Yellow)-Temp-3.0

They do stay cool.

UltraFire%20SZ18650%209900mAh%20(Yellow)-Temp-5.0

Also at "high" current.

UltraFire%20SZ18650%209900mAh%20(Yellow)-CapacityTimeHours

UltraFire%20SZ18650%209900mAh%20(Yellow)-CapacityTime

UltraFire%20SZ18650%209900mAh%20(Yellow)-Energy

UltraFire%20SZ18650%209900mAh%20(Yellow)-PowerLoadTime

UltraFire%20SZ18650%209900mAh%20(Yellow)-TripCurrent

UltraFire%20SZ18650%209900mAh%20(Yellow)-Charge



Conclusion

Any brand name cell is cheap compared to these, when looking at $/mAh. For cheap cells look for brand name 2600mAh cells, never something above 3500mAh.

The rating is, of course, bad



Notes and links

*"Very much below" is probably more correct.

Disassembly of UltraFire 9900mAh 18650 battery

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