1000 lumen+ bike light from $7 flashlights

I found a particular cheap Cree flashlight that lends itself well to being used as a bicycle headlamp if you gang 4 of them up together.  This is a really easy one to build.

This light is rated around 280 to 300 "Chinese Lumens", i.e. it's probably in the 200 - 250 lumen range in reality, but that's still pretty bright.  It uses 14500 LiPo batteries, which are very close in size to AA cells but are a higher voltage.  You can use AA cells but the flashlights will give something more like 100 lumens each if you do.

These are Q5 crees, so be careful that you don't get a dimmer version such as a Q3 because they're sold in identical enclosures.  Also these are frequently sold at a discount so Google for coupons or check on sites such as Slickdeals for a good price.

Unfortunately because of the batteries and accompanying charger, the cost of the components is more than the cost of the four flashlights (ie under $30), but if you already have some of those cells and a charger (or just want to get some anyway to try stuff out) then this is a cheap build, otherwise if all you want is a very bright light off the shelf, look around for a good price for a Magicshine of equivalent output, it'll take up less space on your handlebar and won't cost that much extra - maybe $60 total.

This bundle will get hot if you turn on all 4 lights for an extended time and are not actually cycling, which is needed to keep the temperature down due to air flow.  However it does have the advantage that you can get an extended run time by simply not turning on all four at once!

Step 1: What you'll need

• 7W 280 lumen focusable cree Q5 flashlight (X 4)  (Alternative supplier) NOTE!!! not Q3 which can look identical
• 14500 batteries (X 4)
• Battery Charger
• Fire-retardant safety bag  Optional but highly recommended
• zip ties
• "Two-fish" strap
• optional small Philips screwdriver

 

Comments

[Bilal Bin Siraj]

Ref step 2
perhaps you would like to leave one of the lenses that give you a directed spot light way ahead of the other three LED's flood effect.
try that and let us know the difference

[rimar2000]

Good idea, but

1. Really do you need that big amount of light?
2. Do not dazzle the oncoming? That would be dangerous for you.

[gtoal]

1) Yes
2) It's no brighter than a motorcycle heardlight. Do motorcycle headlights make motorcycles more risky?

Trust me, in the US, car drivers are generally so bad that it's important that both oncoming and tailing vehicles see you (and side-on vehicles - I have a lot of retroreflective tape on my bike and am currently adding EL wire.).  Lighting up the road ahead of you is almost a side-benefit.

I never once felt at risk biking in London for years, but here in a small Texas town I feel like I'm taking my life in my hands every time I go out.

[glorybe]

You are at risk. I bicycle to get around myself and also spent over 40 years on motorcycles. Crashes are a fact of life and often simply can not be avoided. Think about how many cars are struck from behind while at a light or stop sign. Modern cars have all kinds of lights and warning devices and are large and still get smacked. Wearing a helmet and gloves are a beginning but still one needs lots and lots of medical and disability insurance. On top of all of those problems we also have people that actually want to smash into others these days.
We all take our chances and it sort of sucks.

[rimar2000]

Well, congratulations. I'm sick to come across at night, in poorly lit streets, cyclists dressed in black, riding a black bicycle, without lights nor cat eyes, nor reflective stripes. And sometimes, to complete the picture of terror, carrying a child ...