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A phone charger question. Answered

My phone takes 5volts to charge. I took apart a 9volt battery and took out one of the mini 1.5volt batterys. Then added a USB female end and an led. If I add a led to use up the extra 2.5volts will it work for charging my phone or will it over power it and not charge at all?


the circuit that your describing will not work, a LED will function as a resister how ever they are vary delicate and will not allow a sufficient current intensity to charge your phone, what I suggest is that you use a voltage regulator you could get more info on it at https://www.instructables.com/id/SKH2HLJFAQDXA9N/

Using a linear regulator like the 7805 wastes some power as heat. If it's a Motorola, then you need a 30 ohm resistor in the right place. Judging from the schematic you drew, though, you probably already smoked the phone.

it a good thing that you had the led in place or this circuit could destroy your phone because you have some weirs crossed, the way it should go is the negative end of the battery should go to the black weir and the middle pin of the regulator then connect the right pin of the regulator to the red weir, then the left pin to the positive end of the battery, the led is not needed. the green and white wire is normally used for transferring information so they should not be connected to any thing.

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so ignore green and white altogether, or connect them? they tell the phone to turn on the flashing charging picture right? mine doesn't flash but you know what i mean.

the green and wight weirs are only used for transferring information such as files in other usb device. for charging you phone you only need the red and black weirs. the green and wight weirs should not be connected to any thing. since the a battery and regulator and battery can't send or receive files it doesn't need the green and wight weirs. so cut them then cover them with tape so you don't get a short circuit. if it still will not work then the problem might be where the power goes in. do you plug the normal charge in a usb or a separate round plug if so then you need to make a new plug to charge not the usb, you can find out more on this at http://www.metacafe.com/watch/621701/usb_cell_phone_hack_charge_it_with/

I got a voltage regulator but the guy didn't know what the hell he was selling so i had to guess. I'm fairly certain i got the right one but it still doesn't work. i also got 2 green 2.6v LED's if that helps. the one I'm using now is a yellow one. I dont know what it takes. i got it from and old PC. Can anyone either tell me whats wrong with it or give me any pics. That would be a great help. Thanks.