Maybe not the safest electronics* but dirt-cheap and bright as @$%&.
Disregarding some safety issues* I was annoyed by the cumbersome way of attaching and detaching it to my bike.
Well, ok, the included mounting material some kind of works, but... Meh.
So I was thinking about some quick-release solution for days and days until I had some bright moment when I saw my mini spring clamps, pretty much identically constructed to these:
or maybe more like these:
Against all my expectations this worked so fine as it had been made for that purpose...
So see the next steps.
*Not waterproof as described and the low battery warning does not work, instead it suddenly switches off, leaving you in the dark. The included charger / power supply gets pretty hot if the battery is fully drained. You´ve been warned!
But disregarding those 'minor' safety issues, it works fine ;)
Step 1: Materials
CREE T6 Bicycle light kit or sth. equivalent
Mini spring clamp
Optional: piece of road bike inner tube
Optional: butyl sealant
PET soda bottle and twist-off cap
Optional: piece of foamed plastic
Optional: butyl sealant
(No extra pictures of the materials needed for the battery bottle, I forgot in fever... See annotations in the pics and have mercy.)
Step 2: Tools
Optional: lighter / torch
Step 3: Detach Old Fixture and Make the Lamp at Least Splash-water Proof
After detaching the holder you will see why this lamp is not "100 % waterproof" as described (not even mentioning the battery pack and the joint between lamp and battery pack).
Disregarding the unlikeliness of gravity-ignoring water "flowing" into the housing while it´s attached upright, you eventually might want to seal that gap. I used some tiny amount of butyl rubber sealant for that purpose.
Step 4: Preparing the Clamp
Then drill a hole into the clamp, preferably with a wood-drillbit which gives you some centering-assistance. Metal-/plastic drillbits tend to glitch out of center while drilling at low speed and you very likely don´t want that to happen.
Put in the (new and probably longer) screw all through and tighten it using a screwdriver. You can bend the clamp a little for easier accessability.
Step 5: Finished Part 1
If you also want a quick-release and water-proof battery containment which fits into your bottle holder and stores all the cables, then continue to the next step.
Step 6: The Battery Container
Cut out the middle section. Make a little slit into the upper section so you can squeeze it into the lower section of the bottle, see picture.
Measure the diameter of your cable and the length of cable you need from your bottle holder to your handlebar or wherever you would like to fix the headlight.
Drill a hole of that diameter throught the center of the cap of the soda bottle.
Then cut from that hole to the edge of the cap in a straight line preferably in an area with no threads.
If done so, you can twist the cap and insert the cable into the center without damaging it.
Once the cable is in place, twist back the cap to it´s original position.
This should be "splash-water protected".
Step 9: Welding PE (optional)
To close that cut in the cap and to make the cap (maybe) grip better to the threads of the bottle (?) you can try to weld it a little.
This is optional, has the capability of destroying your previous work and it probably would work fine without this step, so be careful.
Otherwise just skip this step.
Step 10: Add Padding and Seal the "bottle"
There´s plenty of room in the bottle to store all the overlength cables and even to pack a spare battery, but I did not think about pulling out the cable of a spare battery yet, since I don´t have one.
Join the two parts of the bottle and wrap some insulating tape around the joint. If you apply some steady tension while wrapping, it will look nice and also will be almost waterproof (if you don´t submerge it in water).
Wrap some rounds of insulating tape around the lid, too.
Optionally seal the cap with some of the butyl sealant.
Step 11: That´s It, Have Fun!
Now really almost waterproof (but still not suitable for diving).
Annoying cables and joints are stored securely and waterproof, but remain accessible and adjustable.
Step 12: Optional: Adding a Low-beam Light Mode/diffusor
As bright as they are, even on lowest setting, the much they blind opposing traffic.
This might be a workaround.
This lamp has 4 modes; "A": 1 LED on top on, "B": 2 LEDs on the bottom on, "C": all 3 LEDs on, and "D": a "strobo"-mode with all 3 LEDs flashing (which is pretty obsolete I think, maybe the "C" mode as well, since it isn´t that much brighter than "B").
But switching "A" and "B" really provides some opportunities.
I added a little heartshaped screen which diffuses parts of the beam emitted in "A" mode, but doesn´t effect "B" mode at all.
Now in "A" mode the lamp is still bright and visible for others, you still have a nice focus and a good illumination of the ground and boundary areas right in front of you, but the probably blinding light is diffused.
Now it´s impossible to directly look into the LED when the lamp is tilted a little downwards (i.e. focus 5-10 m in front of your bike).
If you switch to "B" mode, you still have the "upper beam headlights" for riding off-road or in poorly illuminated areas.
See annotations in the pictures.