Bests & Worsts Reviews from Amazon

Compact, inexpensive, take with you (throw it in your carry-on) kind of power. I bought this for the numerous times I'm out and about, not near a charger. Turns out, this works pretty well! Bottom line, you'll get to 40% iPhone battery charge in 1 hour and 80% in 2 hours. I did a few tests myself: first, drained my iphone 4 to zero. Next, I attached the Stitchway UltraPower 1900, fully charged, onto my iPhone 4. Using a stopwatch, I recorded the following: 15 mins = 11% iPhone charge 20 mins = 14% 31 mins = 22% 48 mins = 33% 59 mins = 40% 70 mins = 48% 95 mins = 65% 119 mins = 79% 125 mins = 79% 151 mins = 79% I stopped timing after 151 minutes. I suspect it takes much longer to get the remaining 20% of battery charge. Enjoy!