inputs.text: imax power imp500 best external battery backup units available - main device iphone 3gs purchased battery months ago anticipation lot traveling going year researched external batteries couple weeks compared imp500 products no contest imp500 hands wanted something small lot juice going stuck boring airports airplanes several hours time imp500s 5000mah capacity allows recharge phone several times needs recharged imp500 advertises 400 capacity standard iphone battery far right money imp500 no longer need even remotely conservative use devices last trip typical airport delays actual flight time surfed played games watched 3 movies course 9 hours drained internal iphone battery twice since left home imp500 able top times plenty juice spare fact got 2 full iphone charges decided plug totally awesome battery capacity expected take fully recharge recharged much faster though would turns although output ie much juice push recharging devices rated 600ma input ie much juice accept recharged rated 1000ma therefore even though 4x capacity internal iphone 3gs battery takes 2x time recharge totally awesome size unit makes portable especially consider capacity put relativelytiny size perspective size weight pack playing cards provided retractable usb charging cable included adapters also extremely convenient although imp500 seems marketed towards iphone users adapters allow used many devices ive used miniusb adaptor not charge phones also run garmin gps unit forgot cable many times say awesome unit comes iphoneipod adapter miniusb adapter third one dont recognize trapezoidal half height miniusb adapter think blackberry adapter havent needed one yet nice know 3 mostpopular adapters come indicator lights unit also helpful easy see give clear indication much charge leftunless use power button turn unit charging blink intuitive style tell pics unit looks good smooth surface rounded edges make easy hold slip pocket backpack whatever finally price couldnt believe saw expected battery like one fits needs cost significantly mainly thats competitors seem charging deal product awesome