inputs.text: like carrying portable outlet - far external battery packschargers go one great utility seems retain charge long time quickly recharges iphone 4s example lightweight smarts turn not connected though downside theres no direct way manually turn two usb output ports sufficient current another port 21a vs 1a charge many larger devices ipads traveling without regular access nearby outlet serves portable refueling station adding minimal bulk weight im go im flying halfway around world business makes handy useful travel companion portable electronics