I admit I short charge my lights all the time. But there's no way around it - if I have a detour or decide to do an extra training ride, I simply can't get caught out in the dark without lights. Same with the cell phone - you'll find yourself batteryless when you need it most.

For sure, I'll try and deep discharge as much as I can , but it's too impractical for my critical items like hi-lumen lights (and phones).