A portable luxeon bike light

Create a portable bike light with enough power to see where you're going.

The goals here are:

* Enough light to see the road.
* Battery life of at least two hours.
* Easy to attach and remove.

Step 1 A note from the future

I'm already at work on the next version of this bike light, and I thought I would share the details, since you may be more interested in that design.

* Battery -- Makita BL1830. The arrangement of 8 AAs works well enough, but swapping out eight batteries at a time is a nuisance. The Makita weighs about 700g, but mounting a slide connector to the bike would make for easy use.
* Light: Cree XR-E, from the brightest bin. LEDs from Cree and Seoul Semiconductor now outperform the Luxeons, though Cree seems to be the easier to find optics for.
* Connectors. I definitely want to switch from a single connected wire to a detachable cable, using EIAJ connectors, for example.

I'm still pretty happy with the Cateye as a mount, though I'd love to hear from you if you have mounting scheme that works better for you.

Comments

[insanityideas]

I too also built a light like this using the same referenced indestructable for guidance (I used a mosfet out of a computer power supply rather than a buckpack, and have 3 brightness settings). I have a suggestion for mounting for you, having had one of these Cateye lights I know they are a bit all round iffy. I used the plastic mounting bracket that you get for bicycle reflectors (virtually free from any bike shop). They are adjustable for position and fit just right around handle bars. Then you just wack a hole and a bolt through the casing of your light. Use a nylock nut to stop it coming undone. This worked for me because I was using an aluminium box (basically a mini electrical wiring junction box), which was also the heat sink. And I was designing a light I could just leave on the bike all the time. This meant I wanted something that wasn't quick release, so that people couldn't easily knick it. I have become fed up with all the different things you have to quick release off a bike when you lock it up, and figure lights can be made to look like they arn't worth the effort of stealing. This has drawbacks for anyone that wants a detachable light... but is very cheap and effective fix for anyone that doesn't care about detach-ability.

[Scott_Tx]

FYI you can get 3 watt Luxeon K2s from this place for $3 each: Kaidomain

[altadenarida]

What's your thought on Luxeon K2s versus the Cree XR-Es? I'm really on the fence at this point. Since I'm going to an 18v Li Makita, I guess the big question is which is best driven by that battery, in the "4 bulb" range. Whatever you're buying, be sure you understand the "binning" procedure of the manufacturer, which is usually spelled out in the spec sheet. That'll help you get the brightest, truest light you can afford.

[Scott_Tx]

The Crees are brighter but those are a good second place for 1/3 the price. That page also has some current regulators on the cheap too.

[joejoerowley]

Cool! I bet is really bright! Great Instructable!!

[altadenarida]

Thanks, yeah, it is really bright! Right now, though, it only really works for less than four hours at full burn. For me, that's about three trips home from work. That's why I'm so excited about the Makita-based light. More burn and a single "slide out and throw in the charger" approach would make commuting easier.