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By phinsil6
#145318
Hello,
I have been trying to use the LiPo Battery Charger/Booster from Spark fun (http://www.sparkfun.com/products/10300) along with a 3.7v LiPo Battery (http://www.sparkfun.com/products/8484) . Theoretically, since the charger/booster outputs 5v, i should be able to charge an iphone with it. however, even when everything is fully charged, nothing happens on the iphone end. setup is pretty simple: battery to charger, charger to usb cable to iphone on 5V out pin. and yes i do read 5v on the usb cable, so there actually is voltage going to the phone. so what is the problem here? why wont the charger charge the phone?

Thanks
By Duane Degn
#145319
Your charger probably needs to communicate with a PC before it will draw much power from the USB port. A device has to request power from a PC over USB before drawing more than minimal current. Since your charger isn't able to communicate with a PC it never starts its charge cycle.