Why does high efficiency matter?
Higher efficiency means longer run time at a given brightness level from the same set of batteries. The difference in run time between 96% and 85% efficiency is not that dramatic — about 45 minutes of extra run time on the High setting out of more than 6 hours. But there are other advantages of high efficiency. The energy wasted in the DC-DC converter turns into heat inside the circuit, introducing failure modes and reducing reliability. The 85% efficient circuit must dissipate almost 4 times as much heat. A further advantage of high efficiency is that it can run brighter. Turbo mode is thermally limited after a few minutes of operation in still air. A 96% efficient circuit permits nearly all the heat to be emitted by the LEDs, while an 85% efficient DC-DC converter requires the LEDs to run about 11% less bright in order to maintain the same temperature.
