I use my laptop mainly in the office so generally it would be connected to the charger all of the time. WIRED seems to think that this will kill my battery and that I should instead cycle between 80% and 40% capacity. Very well, I can’t change my habits but I sure can make stuff to have the same effect.

This project is a Bluetooth relay controlled by my laptop. I plug in the laptop charger into the output of the relay. A bash script monitors my laptop charge in the background and switches the relay on and off to maintain the mythical 80-40% charge level. I’m not fully sold on the idea of cycling the battery vs fully charging it. I’d love to hear from someone who knows their Li-ion battery chemistry.

I published a step-by-step tutorial for this, including the CAD files and all of the code. It got featured at Instructables.