Originally Posted by Rob_E

I got this, but then I was charging an iPad, an iPod, and a phone. For just a phone, you could go with something much smaller and somewhat cheaper, I imagine. Actually, my battery is not a good candidate because it does not charge from USB. Any good candidate should charge up from USB, and another nice feature would be the ability to be charged and to charge another device at the same time. Then you could possibly have the battery charging while it was charging the phone, so when you got off the bike, both the phone and battery would be topped off. Of course if you're not using your phone extensively, then that might be overkill. My old, non-smart phone would last for a couple of days as long as I remembered to turn it off when going through dead zones or poor reception areas. I'm less optimistic about my iPhone.