I want to make an USB nokia charger for my 7650. The usb port outputs 5V, max 500mA. The charger that came with the phone says it outputs 5,7V 800mA. Seeing that both amps and voltage is a tad LOWER than the that of the carger - would the possible malfunction ruin my cell, or just *not work* ?
You could ruin your usb port by trying to draw too much current. Chances are that the charger is rated at 800mA so that the phone can be charged as well as recieve/make calls. Hook up your multimeter and see what it draws on charge and when making calls or using other functions... Most lithium cells are 3.6V so a slightly lower voltage should not cause problems for charging of the cells.
Ok. Yes, its a 3.6V li polymer battery. Honestly, I don't know where to measure this thing when charging. I obviously cannot measure at the phone, and the charger is a mean mofo when it comes to showing its guts. any ideas?
I have made a cable to power and charge my Dell Axim X30 from the USB port. The supplied PSU is 5.4v and 2.41A. It works perfectly. (very useful because I can keep the PSU at home and use the cable at Java training, where the AC outlets are either used or hard to reach and USB ports on the front of each PC) Other owners of that SFF have also made cables.
mod a usb port... wire the + and - of a usb socket on your computer directly to a molex connecter. that way you can pull pretty much as much current as you want ;