DIY Led Light Bomb Using Old Laptop Battery




About: Being a science student i love to indulge in projects related to engineering as i love to learn things practically...

  1. Its time to have a blast of light in my workspace....
So in this instructable i am going to show how to make yourself a rechargeable,ultra bright led light out of an old laptop battery.

Thanks for reading this instuctable. Please rate it and visit my youtube channel for the complete video illustration of this project.

Step 1: Wooden Box (enclosure)

I started up by making an enclosure that packs the battery pack as well as a switch, a charging port, the heat sink and the led panel itself.
I have decided to use bidding wood panel to make this box.The height of the box is 3 inches so i have selected the wood accordingly and selecting a nice pattern to give the box a neat look.
Four sides are cut at 45 degree angle using a miter saw and it really help putting the sides altogether neatly.Afterwards adding up a base plate cut out of a 3mm plywood sheet and then put up using four screws.Moreover some triangular wooden pieces are glued at the top side of the box to reinforce the box and to provide a base for the aluminium sink.
The dimensions of the box is totally dependent on the dimensions of the battery you fetch from the laptop battery and choosing the heat sink and led panel accordingly.

Step 2: Battery Pack

To me this is the most fun part of this instructable.
Usually buying new lithium polymer cells for such type of project can sometime cost too much.So i have come up with an idea of using old laptop batteries to save some $ and add a bit of creativity to the project.
The battery pack that i have got is from an old toshiba laptop ratted at 11.1v 4000Mah.
Well the battery pack have surely lost some of it capacity but still all the six cells are in good condition.
While selecting a battery pack always:
.Check the individual cell voltage,anything inbetween 3.7v to 4.2v is good to go.
.Make sure the cells are flat on both sides,usually the swelling on lipo cells shows their deficiency to put up a good capacity.

Step 3: Switch and Charging Jack

Now I Added up a switch and a charging jack on the box.To wire the up i simply connected the battery terminals to the jack while the switch is connected in series.
I have used a regular 6 mm charging jack as most of the 12v chargers usually comes with the compatible pin.

Step 4: Putting It Altogether

Now gluing the aluminium heat sink at the top.I have got this nice big heat sink from an old PC.
After that i have glued down the led panel.
This is a 12v Led panel usually available from you electronics supply store.
PROS: This Led panel is extremely bright so it can light up a good sized work place.
CONS: The led panel gets very hot if used alone so always use a good sized aluminium sink to ensure the temperature must be kept as low as possible.

After putting it up altogether, its time to light it up and use to put some extra light in your workplace or it can be used for photography as well.

On one complete charge the light goes on for more than 2 hours, So i guess for an old laptop battery it fairly good to go with.

Thanks for reading this instuctable. Please rate it and visit my youtube channel for the complete video illustration of this project.

Abdul Samad.



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    11 Discussions


    2 years ago

    Nice build, where did you get the LED from?


    2 years ago

    Hi, did you re-use the charging control circuit, are the cells series or parallel? someone may have a nasty cell bursting experience without some more details on the wiring side of things.

    1 reply
    DIY KING 00snowy1998

    Reply 2 years ago

    No i have not been using the charge control circuit that comes with the laptop battery.
    As the Led needs 12v so i have connected 3 cells in series and the connect it with the remaining 3 cells in parallel to increase the capacity.


    2 years ago

    Athough the overall design looks fantastic I'm slightly disappointed that theres is no fan inside the base. Without is the heatsink can handle far less power I'd guess about 10-20W at this size.

    1 reply
    DIY KING 00nqtronix

    Reply 2 years ago

    you are right..... i would have been much better to use a fan ....may be from a pc .... as the heat desipation in the current case is not very good....
    Thabks alot for suggestions .... i will definately try it next time