This video will show you how to make a powerful rechargeable LED emergency light at home out of old laptop lithium 18650 batteries. This is a very cheap led light & can be easily made at home. You don’t need any special skills to assemble it. You can use it in different places of indoor and outdoor.
of 18650 Lithium LED light
Take any scrap battery pack of an old laptop and remove its battery cells from battery compartment.
Select a good working pair of cells in parallel and solder two small pieces of black connection wire to the negative side of it.
Bring the wires upward. Now take a small thick piece of sponge and stick it to the bottom of cell to increase its height.
Take 3 volts of led light plate and stick one side of a pair of Lithium batteries.
Connect one wire coming from downward to the negative point of led light plate.
Solder the positive end of a diode 1N4007 to the positive side of the Lithium battery pair at the top. Take one on/off switch and also solder its one end to the same place as shown in the following image.
Stick a piece of sheet to separate the components at top of the positive side of Lithium batteries to avoid any short circuit.
Assembling the upper part
Take a small piece of red wire and solder its one end to the positive point of LED light plate. And the other end of on/off switch. At this stage the basic circuit is complete. You can glow the LED light by pushing the on/off switch. Now we will prepare the charging circuit for lithium batteries. Take a charging socket and stick it at the top of the lithium batteries.
Solder the negative end of diode 1N4007 to the positive point of charging socket.
Take a 3v DC LED and solder its negative end to the negative point of the charging socket.
Take a 1k resister and solder its one end to the positive end of LED. And the other end of 1k resister to the positive point of charging socket with the diode.
Now insert the 5 volts adaptor’s jack into the charging socket and turn the power on. The LED should glow. The current will pass through the resister and will go to the LED positive while the negative of LED is connected with charging negative. And also the positive current will pas to the Lithium batteries through the diode. While the diode will not allow the return voltage.
Turn the power on and use its full brightness.
Warning: Do not keep charging the batteries for long time. This project do not have any charge protection circuit attached with it. Long time charging might explode the batteries. Try to attach a charge protection module to avoid any incident. Thanks for watching video and visiting the website.
List of components
used in 18650 Lithium LED light
- 18650 Lithium cell 3.7v x 2
- 1N4007 diode x 1
- 1k resister x 1
- LED red color x 1
- LED plate x 1
- On/off switch x 1