So the other day my wife said that she needs some portable lights, for some twilight markets that she’s going to. I had a nagging feeling that we had a solution somewhere in our home, but I couldn’t think of exactly what it was, so we went to look at Bunnings. And let me tell you, they had a HUGE range of unsuitable options that were all various combinations of:
- Too expensive
- Too weak
- Too focused
- Requiring AA or AAA batteries
- Having built in batteries that won’t last the whole evening.
What I needed what something that would:
- Use high capacity, rechargeable batteries
- Ideally use replaceable batteries, so that I could have multiple batteries ready to go (giving extended run time)
- Produce plenty of light (ideally 2000+ lumens)
- Spread the light well over one or two tables (not so diffuse that you can’t see well, but not so focused that it’s like a spotlight)
- Cost little or no money
- Reuse existing materials, to reduce waste (because the environment is important)
So in my head I crammed together all of the spare parts and bits and pieces that I have laying around the house and garage, and here’s what I came up with:
- We have plenty of standard LED lightbulbs of various power ratings and good brightness (shout out to the Lightbulb Audit), 240V AC.
- We have plenty of bedside lamps
- I have a 12V DC to 240V AC inverter in the car.
- I have a 16-24V to 12V power supply on a wheelchair robot, that’s gathering dust in the garage.
- I have multiple 20V cordless tool batteries (for the electric lawn mower), with enough capacity to power a light source for hours and hour. These are Xfinity (i.e. Aldi cordless tools) batteries. We have 2x4Ah and 2x4Ah batteries.
When I put them together in that order, I had a system that will achieve all of my requirements. All that it needed was some 3D printing to connect it all together and make it look flash. I also needed to buy a lighter socket from Jaycar, so that I didn’t have to dodgy up the connection between the DC converter and the inverter.
Check out the 3D models on Thingiverse if you want to print a copy for yourself: https://www.thingiverse.com/thing:3867871
In the end, it all connected up neatly together, and actually looks really good! I think I’ll upgrade it in the near future to include a USB output (I have a 12V to 5V USB charger adapter laying around) and maybe include a set of 20V and 12V output screw terminals, just for the heck of it. And maybe I’ll make some other random DC tool attachments!
You can see in the photos some red “speed stripes” on the battery connector… I may have trial fit the connector before I’d finished removing all of the support material post-printing, which caused a delamination crack, so I had to use my 3D pen to weld it back together along the crack.
After some testing, I confirmed that I can get about 1.5 h of run time, using a 2 Ah with 3 lamps totaling 19.5 W rated power.
For the parts I used:
Crimped spades: https://www.jaycar.com.au/male-spade-red-pk-100/p/PT4512
Batteries: Xfinity cordless tool batteries (Available intermittently from Aldi)
DC-DC converter: Unsure. Just needs to be rated for 20V input and 12V output, as high a current rating as you can get. I’d say aim for 2A minimum to run a couple of lights. Ideally much higher.
DC-AC inverter: 150W 12V DC to 240V AC inverter. Available from Jaycar.