DIY Long Battery Life Bicycle Indicators





Introduction: DIY Long Battery Life Bicycle Indicators

About: I like to make stuff in my free time. Especially programming, cooking, electronics etc. Lately I'm making tutorials about stuff I made the last few years.


LONG BATTERY LIFE. Circuit is completely turned off when not blinking.





Step 1: Video

Step 2: Parts List

2 x LED's (I used car LED's working on 12v that I found in a car parts shop for under 5 bucks)

Multi-pole switch

9v battery connector

9v battery

Small solder board

555 timer ship + socket

2 x 240 Ohm resistors

1 x 100 Ohm resistor

1 x 500 Kilo Ohm resistor

1 x 270 Kilo Ohm resistor

1 x diode 1n4148 or 1n4001 (most standard diodes will work)

1 x capacitor 100 micro farad

1 x capacitor 1 micro farad

1 x capacitor 10 nano farad

Electrical wires

Housing (for circuit and battery)

Step 3: Putting It Together

Solder everything together on the solder board.

If you use ready-to-use LED's, you have to bridge the resistor in the LED casing.

Step 4: Circuit Ready

When you soldered everything together, it's time put it in the housing.

It should look something like this.

Step 5: Final Notes

I made this circuit as a request of a friend.

He painted the indicators and mounted them to his bicycle.

He is making a step by step tutorial on how he mounted the blinkers on his bike. This will soon appear on the website.

To see updates and more info on this project, please visit the website at

Please leave suggestion and comments below.

Thanks for reading,

Tom Heylen



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    14 Discussions

    Be better if the signal lights were separated out to each side a little more. They're so close together that from any distance drivers would probably have difficulty telling which one is blinking.

    1 reply

    That is a very good comment. When dark, blinkers always work in relation to a center light. When there is a center light, it does not matter how far the indicators are separated. I show you a picture how my friend uses his normal lights together with the indicators. Thanks for the comment.


    It's too bad you didn't list a brand and part number for the lights. I like them but can't find them anywhere.

    Hi, how much is the voltage drop on leds, can you tell me?

    This is super awesome mate ! Would you please be kind and upload a video. I would really appreciate. Also what changes one have to do if its 1.5v or maybe 3v (1.5 + 1.5) Since the battery of 9v is not cheaply available in my country.

    1 reply

    I would go for 3 x 1.5 v = 4.5v to power the circuit. You have to
    change the 100 Ohm resistor to whatever your LED's require. This is
    probably a 300 Ohm resistor. Also have to replace the 2 x 240 Ohm resistors. To calculate: R < V led / I 555.

    I love this idea! I always hate the "arm indication" because sometimes is not safe! Where is the box mounted on the bike? I would add two extra LEDs for the front, maybe on the handlebar. In this way it would be visible also for the cars coming from the front.

    Great 'ible! You should intergrate a rear light, with bulit'n brake light! Just a push switch to the brake lever :) Would'nt be too difficult with your expertice :)

    Hi Sir, is there any chance that u can build a flashlight or somethin like an emergency lamp that the battery will last for a year ? thx u ^_^

    Also looks AWESOME. You should go into mass production ;)

    1 reply

    Lol. I like the hobby part and share to the world. You want to pud it in mass production, go ahead... no patents on this one and I wish you the best.

    That's a novel and unconventional use of a 555. How did you come up with it?

    1 reply

    I've been struggling with this circuit for a while since I wanted it to
    be battery efficient. Luckily I have a friend who is a master in
    electronics and a doctor in physics who helped me out with this circuit.