When your smartphone battery life is significantly low (red) and you have to put on hold your social life utilising the phones capabilities until you get home to recharge.
Person 1 - Hey, you cool to hang out?
Person 2 - Yeah, sounds sweet.
Person 1 - Okay, where you want to meet?
Person 2 (5 hours later) - Hey, sorry. Interrupred, couldn't reply to anything. 2% when I finally got home.