Did you know the MacBook has a setting to power off the keyboard backlight after a period of inactivity? I didn’t. This is the same concept as the Energy Saver feature for your display.
The setting is here: System Preferences > Keyboard > Keyboard > Turn keyboard backlight off after X secs of inactivity.
This isn’t something I would use all the time but it could come in handy in a pinch. Give it a try the next time you’re in a situation where you need to conserve your MacBook’s battery power.