I’ve just received my “P5” light as purchased through GearBest here:
http://www.gearbest.com/led-flashlights/pp_71050.html
…for $15.47.
This light is also available from DX for $14.85: http://www.dx.com/p/zhishunjia-p5-3-x-cree-xp-e-q5-1000lm-5-mode-white-light-flashlight-black-silver-1-x-26650-323057
Contrary to GearBest’s description, this light did NOT have 3x XM-L emitters, but has three very cool-white XP-E emitters.
Although I really do like the external design of this light, is actually poorly built internally. The light does have a beacon switch that can be disabled by a long-press of the button. There is a charging port built into the side of the light, with a relatively fragile looking cover, but I have no way to test the charging function. This light is a surprising thrower, even with the triple emitters. It has a well defined hotspot with less spill than I was suspecting, but this is fairly well negated due to the following issue.
It is moderately driven at <2A on high, through the 3x XP-E emitters. Even at the reduced current, this light is hampered by the extremely poor heatsinking. After running a few minutes on high, some heat had transferred to the body of the light, but the output had visibly dropped, presumably due to thermal sag.
The second big frustration is the 5-mode (High-Medium-Low-Strobe-SOS) driver that starts in High, and has no way to turn off without going through the remaining modes. This is even more annoying if you are using the light on Low, as you get blasted by the full-brightness Strobe and SOS modes before the light will turn off. This driver also has extremely low frequency PWM on Medium and Low modes.
The three emitters on this light are wired in parallel. The individual aluminum bezels (emitter housings?) are threaded into the body of the light. Each housing has:
A GITD O-Ring
2x (!) plastic 18mm lenses
A plastic 18mm x 18mm reflector
The XP-E emitter
A thin threaded ring to retain the emitter, with no thermal compound/adhesive
A steel spring clip to prevent the retaining ring from backing out(?)
The wires are long enough to allow the housings to be unthreaded, and they can be pre-twisted when reinstalling. Unfortunately, this design means the PCB has minimal contact through the retaining ring, into the aluminum housing, and then, through those threads, into the body of the light. It’s a very inefficient thermal path, which greatly reduces the utility of this light. I think that assembling the head and then potting the base with JB Weld would improve heat sinking immensely, but the light couldn’t be disassembled for repair or modification any longer.
The threads on the light are not anodized so it is not possible to lock out the E-switch. My multimeter isn't sensitive enough to measure the parasitic drain present on this light.
I would not recommend this light to anyone. If this light had better heat sinking, better emitters, and a better driver, it would actually be an interesting piece. My intention had been to replace the emitters with XP-sized UV emitters to make a UV triple, but I don’t think this host is suited. I could install the emitters, but the poor driver and heat sinking render this light unsuitable for this purpose.