Smartphone battery life is so shit, on every model, that I always plug my phone in. Even if the cable / socket is only going to be around for minutes. So no saving here. In the days of docks, I dropped phone on dock every time I was at my desk.
My first few phone models (Motorola StarTAC etc) had a battery life in weeks, and I usually had a charger/dock with space for keeping the phone and a spare battery fully charged.
So from here it sounds like you've made a feature of going backwards at a rate of knots.