Stinger battery quickly dying

I just bought a brand new stinger with battery and ac/dc chargers off of ebay. I charged up the battery in the slow charger for 10 hours prior to use. The light dims(not nice and white) in about 10-15 minutes of use. I understand per the instructions that a few charge/discharge cycles may be required to achieve full capacity, but 10-15 minutes of use is ridiculous. Is this normal? Is the battery defective? Do I need to show proof of purchase for streamlight warranty repair? I guess I can print them out my paypal/e-bay transactions? Help! Thanks.

That is most definitely not right. If you had one bad cell, you'd get about the normal runtime but at greatly reduced brightness. The fact that you get short runtime and dim indicates an overall undercharge situation. Just to be sure, cycle it a few more times. Charge it for 12 hours, discharge to dimming and repeat at least one more time. If you're pack is not giving you the full brightness and runtime, you might possibly have a charger problem.

Wilkey

Check the battery's voltage just off the charger, and a few hours later before installing in light. Should be around 4.2 volts fresh off charger, and approximately 3.9+ volts in a few hours.

Bill

Thanks for the information so far guys, I'll do those things and keep you guys updated.

I was charging the battery before I posted on this problem, so the battery was on the charger for about 18 hours. I tested it fresh off of the charger and got 4.18-4.19 volts.
A few hours later it dropped to 4.10-4.11 volts. I'm going to run the battery in the stinger now and see how it goes. Cross your fingers.

So far, so good. It really hasn't dimmed much at all. Nice and white beam, still plenty bright. I think that last charge did it. Problem solved, guys. Thanks for all your help.