jremington:
The battery capacity depends on the load you apply, so it makes sense to use the intended load.Don't let the battery voltage drop below about 3.0V or it will be destroyed.
Yea i have had a few of them go bad trying to drain the down to nothing. They are UltraFire YF 18650 4800-mAh.
I have been having trouble locating a datasheet for them, this is what they look like,
