It might be possible, if the cell phone charger provides 5v. The standard iPhone brick does not provide enough to power mine, but I am using a BlackBerry one I had sitting around. I am also a fan of the Anker charging hubs, I have a few of those around as well, so I can charge multiple USB devices (GoPros, helmet cam, phone, tablet) at once. that works as well.
Check the power output to verify it is pushing enough.