Spark 18650 2600 mAh (Black)
Official specifications:
- Nominal voltage: 3.7V
- Protect circuit: 5A
- Capacity: 2600mAh
- Cut-off voltage protection: 3.0V
- Charging voltage protection: 4.2V
- Assembled in Germany with Sanyo Japan cell
Inside the envelope the cells was only wrapped in a piece of paper.
This battery has a high voltage at low loads.
Conclusion
This battery uses a Sanyo cell, this is a good quality cell and as can be see on the curves the two cells does track very nicely. There will be no problem with series applications of this cell. The high voltage can be an advantage in smaller (i.e. 3-4 watt) lights where the battery replaces two CR123 cells.
The PCB current limit is placed about 30% above the cell specification, this is a good value.
All in all a very good battery.
Notes and links
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