2200mAh is not enough to get most modern phones a full charge, and like all other power banks I seem to have, there must be conversion inefficiencies or storage loss, because I never seem to get listed charge into my phone equivalent to what the power banks list as their stated capacity. Nonetheless, if you keep your expectations reasonable, this is a happy size to tide you over until you can find a proper outlet to recharge your phone, earbuds, or whatever else you use that can plug into USB. As a plus, if you press the little power button a tiny white LED gives you enough light to find change in your car cup holder or your registration in your glove box, etc. Chunkier power banks will give you more charge, but mostly too big to easily fit in your pocket, whereas this is like the size of a roll of quarters. Not tiny, but also not annoyingly too big to carry.