Here in this video i am showing, how to make rechargeable led emergency light from old/used 18650 lithium cells. The light so powerful where I used 4 LEDs of 1 watt each. I used here 3 pieces 3.7 volts lithium cell 18650 from an old laptop battery. All three cells are joined parallel to increase amperes which will increase the running time thrice. I also used here a free charge protection board from used or damaged mobile battery. The board prevents over charging the cells.
used in rechargeable emergency led light
Here are the basic components used in this project. There are one watt LEDs with positive & negative pins. I used 4 pieces of them to make a 4 watts pannel. I also used LED base plate / heat sink for proper heat dissipation of LEDs. 330 ohms resisters and one 1N4007 diode is also used here in this project.
LED light panel is made on the vero board where all components can easily be fixed on it.
Take small piece of wires and solder them on positive and negative points of the LED base. We will insert them into the vero board’s holes and solder them at the back.
Below image shows all four LED bases inserted into holes of vero board properly.
Now put all LEDs onto the base with polarity. Positive terminal of LED will be solder with the positive point of the base and negative terminal to negative point as well.
Take one on/off switch and one charging socket and properly insert into the holes of vero board at left side corners.
Take one green color LED and solder its negative leg to the negative point of charging socket. Also take one 330 ohms resister and solder its one end to the positive point of the charging socket. After that join both remaining legs of LED and 330 ohms resister together and solder it. This LED will act like a charging indicator. It will glow when you will insert a 5 volt charger pin into the socket.
Here I showed the back connections of green LED and 330 ohms resister, as I explained above
Take two pieces of naked wires as the length of vero board. One wire will join the positive terminals of all four one watt LEDs together. And the other will join all negative terminals of all four 1 watt LEDs. Likewise all four LEDs will be connected each other in parallel.
This is the finished board looks like the following image.
Connecting battery bank:
This is the battery bank of 3.7 volts where I used 3 lithium cells from an old and damaged laptop battery. This post is already available at this site. Where I showed that how to get free charge protection board and make a battery bank. I am not going to explain it in detail. You can click on the link above, if you want to read the article or want to see the video.
Take a large piece of steel thick wire and wrap around the battery bank. Also twist it at the end and turn 90 degree upward to make a post.
Solder one end of thick steel wire with the vero board as shown in the below image. The wire should grip the board tightly.
Twist the two positive and negative battery bank output wire around the twisted pole of steel wire.
Connect and solder the the black negative wire to the negative line of LEDs. And solder the positive wire to on/off switch.
You can leave the battery bank opened or use any empty box to keep it safe. I choose an old electrical pvc box for this purpose.
Testing finished product
Here I inserted 5v Nokia mobile jack pin into the charging socket to recharge battery bank. The green 3v LED should glow which acts as charging indicator light.
Here is the final product in action. A 4 watts LED panel provides enough brightness for everything clearly visible in the room or outdoor. This rechargeable emergency LED light can be used for car maintenance as well.
I hope you enjoyed the project. Please share it among your friends. Thanks you.