Smartphone battery life sucks and carrying power banks around with you is one way to keep your handset juiced up. But it's easy to forget to bring a power bank or to charge them up to take with you in the first place. This contraption that you can build yourself could be a good alternative to keep your phone charged up, albeit at the expense of your friends' handsets' battery life.
Hardware hacker Rulof Maker, has made a small portable device can suck the battery from one phone to another. This was done through modifying a few electronic bits and combining them into a gadget that he can carry around on a keyring so he'll never forget to bring it.
What you'll need for this project is a motor from an iPhone fan, a circuit board from an inexpensive USB power bank, a Lightning-to-USB cable, a small wood block and some soldering skills.
Maker's gadget is made to steal battery from iPhones but there's no reason you can't use a micro-USB or USB Type-C cable for this project.
You can watch the video above for detailed instructions.
This post is part of our Evil Week series at Lifehacker, where we look at the dark side of getting things done. Sometimes evil is justified, and other times, knowing evil means knowing how to beat it. Want more? Check out our evil week tag page.