Easy2LED Glow in the dark X-ML (second build)
Hi everyone this will be my second build of a diy bike light. This time its a helmet mounted single led unit with both light and battery being mounted to the helmet.
Here is the list of bits used:
-2x Ultrafire 18650
-Cree XML T6 Led
-PMW 5 mode AMC 7135 2800ma driver
-DIY LED housing
-Ledil, FA11937_LXM_RS_Cree XML, 21mm optic, spot
-Magicshine 1m extension cable
-Lacquer (clear coat)
-18650 battery holder x2
-5A 125-250v A.C Normally closed Micro switch
It was a nice easy assembly using arctic sliver thermal adhesive to glue both the driver and the led to the housing.
Soldering was a little fiddly but was a simple + and - to led and the same to the driver. I split the 1m extension cable in half and glued one end into the housing using araldite. To get the cable into the housing I drilled the appropriate sized hole into the base of the aluminium housing on the flat section as this seemed the easiest option.
To seal the units front glass I used some plumbers tape on the thread to add some water resistance, then to seal the back cap I used a washer slightly smaller than the original thread.
The lens simply falls into the opening and centres onto the led with the screw glass cap to secure it but to add a little more to the lens I made it glow in the dark after being used.
To do this I bought some glow powder of ebay and mixed it with some lacquer to form a glow paint/paste. After popping the optic from its cradle I covered the inside of the cradle with white paint then the glow paint letting each dry before replacing the optic. Now after being lit the optic glows for approximately 5 minutes.
The battery pack I wired up myself, using two battery holders I wired them up in parallel to keep the 3.7 volts but doubling the amp hours. The micro switch was wired in line to the positive feed. This all connected to the other end of the 1m extension cable.
The next step for the battery is a little case possibly made up of some old wetsuit to keep the water off.
The bottom images are the light on 1.High and 2.Low
Nice work. How you mount it on the helmet and aren't light and battery a bit heavy to be both mounted on the helmet?
Here are some photos of how its mounted to the helmet, and the answer is velcro, lots and lots of velcro.
The battery pack it wrapped in velcro and then attached using velcro to the rear vent opening. The light is also attached with.... you guessed it velcro via a small stainless steel z-shaped bracket.
The velcro works really well keeping everything secure.
The weight is at the limit of being usable with the batteries on the back. So far I have tested it on cycle paths etc where its smooth and there are no problems, with no real feeling of a weight on the back of the helmet, however this might become apparent when I take it out on some trails with the added bumps and turns.
The battery pack is wired up in parallel however so I can run it of a single 18650 causing no problems at all except the need to switch batteries half way through.
I like to wrap battery packs in self-fusing silicone tape for waterproofing, and cover with some heat-shrink for protection. A 2-cell pack on the back of the helmet's not bad.
I really want to seal it up this way but at the moment need to take out the batteries to charge in the ultrafire charger.
If any one has any tips or a link on how to adapt the ultrafire charger built for two 18650 batteries that would be great.
So that I would just connect a single connector to the battery pack (two 18650 in parallel) that would be great
I made a connector from a charger so I could just plug in battery packs. EL34 has instructions on his web page. Now I just suggest a $10 charger from eBay for my friends that plugs right into the Magicshine connector.
The link seems to be blocked, but search for
DC4. 2V 1A Intelligent/Smart Charger for 3.6V 3.7V LiIon LiPo Battery Pack USS
I think the problem is that with your batteries wired in parallel, your DX charger would charge the pack if you mod it as seen in this post/pic below, but since you were plugging both batteries into only one channel of the charger, it would take twice as long to charge:
LED Bike Lights 22
Ah ok, so I could link the +ive -ive from one of the charger sides to the parallel battery pack via the connector to charge both batteries at the same time?
I don't mind about it taking longer to charge its just as long as I don't over load the charger with two cells in parallel?
Nice job adleysh, helmet lights are the way forward,
i`ve just done one with a small P60 drop in light wired up to a pair of 18650 in parallel (total 5Ah), just unplug the light and plug in the charger, XM-L pulls only 1Amp so i`ve got at least 4 hours riding time!
that's a tidy little light adleysh, nice job! Charging 3.7V packs is a piece of cake, all you have to do is what adrenaljunky showed with a spare male MS plug wired onto one of those charger channels. If you don't want to open up the charger, you could do the same with a piece of wooden dowel/ rod the length of a 18650 and 2 wood screws. Screw the ends of the wire to the ends of the piece of wood, plug into pack, pop into charger - easy! Just make sure you get it the right way round
Cheers guys, It a pretty effecient little light only had to charge the batteries once so far. Will give your tips a go and wrap the battery pack in self seal then heat shrink.
Also will give the "jam and ram" wood approach in the charger a go.