Picture of Flashing Bike Bottle Light
When you bike in the dark, you know you're supposed to have a light somewhere so others can see you, but sometimes that added bulk is just too much. There's got to be a better way! Now, without further adieu, I present to you....
The Flashing Bike Bottle Light!
Not only can you produce flashing red luminosity, but you can actually drink from it, too! It is powered by two AA batteries that are easily accessible from the side of the bottle. It also has a fully waterproofed LED/switch assembly hidden inside the lid, all while still retaining the ability to be drank from! The part are inexpensive and minimal, so let's get started!

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Step 1: Parts and Materials

Picture of Parts and Materials
Many of the parts I used to make my bottle light could easily be swapped out for similar ones if necessary. The main parts you'll need are:
- A plastic water bottle (size of the bottle depends on the size of your bike's bottle cage)
- A flashing LED that takes about 3 volts
- A 2x AA enclosed battery case
- A small toggle switch
- Two AA batteries (rechargeable is better)
- Velcro (to attach battery case to bottle)
- 150+ grit sandpaper
You'll also need a hot glue gun, an X-acto knife, an electric drill, and a soldering iron

Step 2: Modifying the Cap

Picture of Modifying the Cap
The first thing we'll do is drill a hole for the toggle switch. Depending on the switch you use, the hole size will be different, but most of the time, the manufacturer will print the diameter on the packaging.
After drilling a hole in the center of the cap, screw the switch securely into place. We won't be needing to take it out again.
Next, poke 2 holes to the side of the switch for the battery case leads, and push the leads through.
tybeetom1 year ago
Great simple LED bottle-light.....!
komecake5 years ago
  This would be uber awsome if I had a place to put a bottle cage. I actually had to make an over the should one since my bike didn't have a place to put one. I'm thinking I'll adapt this idea somehow though... hmmm...
copy mines brighter and its universal ha!
cool but I don't get what makes it flash.
The LED itself has a tiny IC inside of it, so there is no need for a separate flashing circuit.
Herminator6 years ago
NICE :D one thing, it doesnt look very bright :(
Radioactive_Legos (author)  Herminator6 years ago
The lack of brightness in the video is actually due to the camcorder's exposure settings. In "real life," however, it is very visible. Thanks for the comment!