DIY mini flashlight keychain

Hello readers. Today I propose for consideration this interesting homemade product.


This is a miniature flashlight, and since its dimensions are very modest, it can easily be hung on a bunch of keys. He certainly won’t bother you there, but he will also help you in an unforeseen situation.

Tools and materials

I assembled this flashlight from three coin-type batteries, personally I used AG5, but you can use others, the main thing is that the diameter approximately matches the LED. Light-emitting diode I took a fairly powerful one, 1 watt, such power of course reduces the battery life, but the brightness of this flashlight is impressive. I ordered these LEDs They are sold on Aliexpress and on the radio market.

You will also need heat shrink tube and a stationery needle. The tools you will need are a soldering iron, wire cutters, tweezers and small pliers.

The process of assembling a miniature flashlight

First of all, we need to find LED negative terminal, align it with pliers and solder it to the negative side of one of the batteries as shown in the photo.





Next you need to bend the soldered contact so that the thermal pad LED and minus batteries are connected.

Before continuing the assembly, we need to check whether we have done everything correctly and whether it will burn Light-emitting diode. To do this, we press two more batteries and connect the free contact of the LED with the plus of the outermost battery.


If everything works, we continue, if not, we look for the reason, perhaps the polarity of the LED is reversed, then you should resolder the battery to the other foot.
Now you need to put heat shrink on the batteries. We select the required diameter and length of heat shrink and put it on the batteries. Leave the LED and the remaining positive contact free.




We warm up the resulting structure using a lighter.
While the heat shrink is warming up, you need to squeeze all the batteries well with your fingers so that subsequently there is reliable contact between them.


Next we need a stationery needle, the sharp edge of which should be soldered to the positive terminal of the LED.



Bend the leg of the LED, press the needle to the body, and bite off the plastic ball.


We bend the remaining tip of the needle into a semicircle and then bend it so that the resulting semicircle practically touches the positive contact of the upper battery.


Check and adjust the needle if necessary. You need to make sure that the flashlight glows when pressed moderately and does not light up due to accidental touches.


The flashlight is almost ready. Now you can put on a small ring and then cut off the required amount of heat shrink again. Now we put it on the entire flashlight and warm it up over the flame of a lighter.





The excess can be cut off with nail scissors or a stationery knife.


Well, at this point we can consider this homemade product ready, we check it and if everything is in order, you can safely hang the resulting mini flashlight-keychain on your keys.




The resulting flashlight shines very brightly for its miniature size.This is certainly not a flashlight for every day, but rather for an emergency. Well, let’s say if the light in the entrance goes out or illuminate your way to the car at night so as not to get into a puddle. Personally, this homemade product has helped me more than once.
With this I say goodbye, good luck to everyone!

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