You never know when a backup battery might come in handy. You could be sitting there, recording your son giving the high school drama performance of his life when, all of a sudden, that low battery warning pops up. Filming HD video drained it faster than you thought, didn't it? Fortunately you bought that iClever Intocircuit 15,000mAh battery on Amazon. Or you will have bought it after reading this post, and your son's play is actually a week from now.
This pack provides 5V/3.1A output through two USB ports, there's a tiny LCD screen that tells you how much of a charge remains, and an LED flashlight comes included because why not? You can currently get it for $28.99, as long as you enter the coupon code INTOCIR1 at checkout.
If that's too much money, there's a smaller battery available for $10 less. It comes with a 11,200mAh capacity, but the small display and flashlight are still included. It goes for $18.99 after using the $2 off coupon INTOCIR2. Try not to get those mixed up.