Xtar 18700 2600mAh (Black)
Official specifications:
- XTAR 18700 2600mAh Protected Li-ion Battery
- Voltage: 3.7V
- Battery Capacity: 2600mAh
- Cell: Sanyo lithium cell inside
- Size(mm): 70 (length) x 18 (body diameter)
- Net Weight: 48g
The battery is called 18700, because it is nearly 70 mm long, but protected 18650 can be just as long, only unprotected batteries are 65 mm long.
This battery has a high voltage at low loads.
The two batteries has slightly different internal resistance and trip current (This might be related).
Conclusion
The high voltage can be an advantage in smaller (i.e. 3-4 watt) lights where the battery replaces two CR123 cells.
It is 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