You somehow messed up your Manjaro config. Sleep and hibernate was working last time I checked. Sounds more like it isn't hibernating at all and then discharges the battery completely.
As for "proprietary looking charge cable" you mean the barrel jack connector? That's about as non-proprietary and standard as it gets, you can literally buy them in any hardware store.
As for "proprietary looking charge cable" you mean the barrel jack connector? That's about as non-proprietary and standard as it gets, you can literally buy them in any hardware store.