Sorry, I must not have been clear. The batteries that Surefire sent with the Fury Intellibeams did and do work. They just don't perform as long or reliably as the Orbtronic 3500 mAh High Drain with button top. This picture helps explain part of the problem.
Surefire obviously designed the Fury Intellibeam to match with their 18650 with USB charger included. That battery is much longer than most 18650s. And, they did not install a spring on the LED side, so a 18650 that has a button top is required. Many lights are designed either with two springs, or with a design so that the head will make solid contact with flat top batteries. The Cloud Defensive and Panasonic 18650s in the picture do not work in the Fury (they work perfectly in the Cloud Defensive and Malkoff lights). But, the Orbtronic works perfectly in the Fury. I am glad that Surefire designed it so that it does have the capacity to handle other batteries than just it's own. I much prefer that design to the one in the original PR1 Intellibeam that was designed for a propriety battery.
It is pretty simple to have some batteries that are set aside for a special light. And, the Surefire Fury Intellibeam really is a special all purpose light for me.
Hope this helps.
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