This is example of why my next headlight will be an expensive bike-specific one. My P7 simply can't stay in one mode for more than 2 miles without switching or flickering, and that's with paper spacers and magnets to secure the battery. And, I've got one completely dead battery out of the two I bought with the light. The Magicshine system doesn't seem to be faring much better, at least by anecdotal evidence.