To get this thread back on topic....... The Vamo is struggling at 9 watts with a single 18350 using a 3 ohm Cisco 306. The battery dropped from 4.2 volts to 4 volts in very little time then it started tripping protection circuitry. 8.5 watts is working so far with the battery reading 4 volts. Edit: Spoke too soon. 8.5 watts is tripping the protection circuitry, though not as bad. Stacked 18350s have no problem.