Measuring battery endurance on real data

How to actually measure your laptop’s battery endurance You charge your laptop to 100%. The applet says “9 hours remaining”. You sit down to work and the thing dies in 4. Sound familiar? There’s a simple reason: the number the firmware (or your DE’s battery applet) shows at full charge is a projection based on the instantaneous power draw at that very second, or on some generic OEM spec figure. If it samples while the laptop is idling with the screen off, you get 14 hours. If it samples w...