The internal 4400mah rechargeable lithium-ion battery can charge a dead iphone 6/6s up to two times! with a 1a charge output, you wont have to wait long while bringing your smartphone back to life.Need some extra light.This battery has you covered.With the built-in ultra-bright led, you're provided with plenty of light to find your phone in the abyss under your seat, in your carry bag or wherever you may need it.This portable backup battery conveniently has an led indicator that allows you to always know exactly how much juice is left.You'll be able to try that out for yourself right out of the package, as this battery comes pre-charged!