Compact 18650 COB LED work light.

thingiverse

This is a work-in-progress simple work light that runs on a single 18650 battery. It has only two modes: on and off, and it draws approximately 1W of power. Depending on the battery, this light will last for about 8-12 hours. There's room in the base for a 7135 current regulator IC, but I skipped that step and used four 10ohm resistors in parallel instead. This project is still unfinished, and it requires significant modification with a soldering iron to get it working properly. I had to put the positive (red) wire outside the case because there wasn't enough room for it inside. I connected the LEDs using thin resistor leads, and then coated the entire area with epoxy to protect those connections from damage. The battery contacts and spring came from an old 18650 holder that was really cheap. The threads needed some wear-in before they'd work properly - they were too tight at first. LEDs can be found on eBay here: https://www.ebay.com.au/sch/i.html?_from=R40&_trksid=m4084.l1313&_nkw=60x8mm+led+1w