Intro: DIY Mobile Modular LED Worklight + Battery Pack From E-Waste
This is my first instructable, I've been an avid reader of instructables since my school days. Decided to make one for the heck of it. Be nice to me.
Having multiple lights for multiple uses has it's pro's and con's. But for me, having something that can be used on nearly all of my tasks greatly helps my economic problems.
I mainly work at my workbench and my car.
The room where my workbench is located has only one source of light, the ceiling light. That one source of light is not enough to illuminate the work area sufficiently. I've tried using small single CFL bulbs and it was too bulky for the small cramp workbench.
Another of my workspace is my car. As I'm living in an apartment the car is located far from any source of good lighting and power. Hence the need of an external source of lighting and power. Even though the car has it's own battery, I'd rather not run it down powering any light source.
What stuff I used
- LED strips
5630 SMD strips 2 meters (link)
- A plate of any sorts
- Salvaged from HDD
- Soldering iron
Optional stuff that you won't need but are recommended
- A salvaged ATX power supply unit
- 12V recommended
Step 1: E-Waste Salvaging (Magnets)
Another man's trash is another man's treasure.
Salvaging parts from discarded trash reduces cost termendously. In this case I'm salvaging neodymium magnets from harddisc drives (HDD).
- Philips screwdrivers
- Torque screwdrivers
- Clamp of any sort
First you'll need to remove the cover of the HDD by unscrewing all the screws on the HDD. And I mean ALL of them.
Most newer models eclusively use torque screws. This older model has philips screws which makes it easier to open.
After opening the top cover, proceed unscrewing the inner screws locking the magnets.
After removing the magnets from the HDD case, you'll find out that the neodymium magnets are glued to their holders and we'll extract them by using a vise to clamp the metal part.
DON'T clamp the magnets or you'll risk damaging the magnets.
Using pliers or in this case I used Clamp Pliers to bend the metal holder part. This will dislocate the magnet from the holder. Pry off the magnets using a flat screwdriver.
Now you have a valuable rare earth magnets to use. Hurray
Step 2: E-Waste Salvaging (Batteries)
I've got this USB powerbank from a while back. It was cheap and to my dismay totally useless. Forward 2 years, it's been sitting in storage. I might as well repurpose it while I can. I opened the case a while back so I don't have the pictures but it was a simple screw and clip opening job.
Inside there was 6 18650 li-ion batteries. Careful in disconnecting the wires so it wont short anything else.
I'm trying to make a 3s2p Li-Ion battery pack so it'll have an output around 10.8-12.3V to power the LEDs. It's currently connected in series so it outs 3.6V.
Step 3: (Optional) E-Waste Salvaging (ATX Power Supply)
ATX power supplies are a common thing in desktop computers. If you want cheap and reliable power supplies without splurging out much you can always tap a used ATX power supply unit (PSU). On a ATX PSU, there are 5V, and 12V and several other voltages but we're focusing mainly on the 5 and 12 volts rail.
On it self, we cant switch it on by just switching the incoming AC voltage on. It has an internal switch.
To switch it on we have to locate the 24 pin connector that usually connects directly to the motherboard.
On it there is usually a green wire. If we short the wire to ground (black wire), the PSU will startup and function.
An ATX PSU is a little bit bulky but I'll be using it at my work table so it won't be a problem. Buying a standalone PSU of comparable rating will probably cost 2-3 times as an ATX PSU.
Step 4: Making the Main LED Plate
I had a white plastic plate laying around. Rather than buying a new one I'll just make a use of it.
I had 5630 SMD LED strips from a previous build of mine. It was from my workbench ceiling. It wasn't very useful because it was only lighting my workbench and not much more. It is very bright. Bought it off ebay from China.
The LED strips can be cut to size and be placed wherever you want because it had double sided tape on the back. The adhesive was still good so I didn't bother applying new tape.
Step 5: Solder the Connections
On the strips there are only 2 connections which is 12V and 0V/GND. You need to either parallel them together or series them. I'd advise to parallel them because it'll be easier if one strip dies out on you the others won't be affected much.
After finishing soldering the LED strips, solder a connector of your choice to the 12V and ground (GND). This will make it easy to connect and disconnect from different sources for example batteries or PSU's.
Step 6: Adding Magnets on the Back of the Plates
Using the neodymium magnets we sourced from the HDD earlier, glue it to the back of the plate with glue. I used super glue. Any other glue can be used such as epoxy glue and contact adhesive. But I'm a cheap person so I used the cheaper option.
Step 7: Testing and Comissioning
Before testing on the LED strip, I'd advise you test the PSU first with a multimeter. The one I used had a good reading of 11.9V on the 12V rail and 5.1V on the 5V rail. Rarely you would get precise voltages especially on salvaged old ATX PSU's.
Connect the 12V and GND to the PSU and switch it up.
Using my multimeter I also got a current reading of 1 amp.
Using the power equation of P=IV
I=1 Amp, V=12 Volts
Considering it was LEDs, it's nothing to be amazed of.
Step 8: (Optional) Tripod Stand
I had a banner tripod stand laying around from my wedding. As it was doing nothing, I thought to myself why not just use it to hold the light.
Lucky me the tripod stand was made of steel tubes and not plastic. So I just attached the magnet part of the plate to the pole and it works as intended.
Step 9: Field Testing
Like I said earlier, the other workspace that I have is my car. Because I don't have a driveway or a garage, the parking lot is all I have to work with.
I intended to use the Li-ion batteries that I salvaged from the USB powerbank but, I didn't have the required balance connectors so I opt to field test using my older batteries that I used with my RC quadcopter.
Using a semi charged 2600mAh 3s LiPo, the light switched on pretty brightly. I say semi because I didn't charge it fully. Also to take note is that the battery was only capable to carry 1400mAh of charge due to age and previous usage.
I runned down the batteries till a cell was at 3.3 volts for safety reasons. It did take around 1 hour for the voltage to got from 4.1v to 3.3v.
Lighting was great. It illuminated the area sufficiently.the engine bay was ultimately bright.
I'll be putting the LED strip on my workspace. I'll update the instructable when I do.
I Attached the plate at my work area. It's a messy table, still it's a bright messy place.
I fully charged the 2600mAh Lipo battery I had. The thing is still going strong at 2hours 20 minutes.