Tuesday, October 13, 2009

Make yourself a Nokia N series USB Charger cable

Many a times I forgot my charger at home and the battery died while at work. Carrying a charger worked opposite as I forgot it at work. Earlier I used my mobile for internet access and it required charger to be plugged in to avoid disconnection. Plugging laptop and phone to their chargers and connecting via cable caused chassis current due to unbalanced ground connections. Nokia had a data cable + charger cable but its not available around here. I could buy two chargers but creating a chargerless solution for yourself seems more attractive :)

Follow these simple steps to make yourself a Nokia N series USB Charger cable. This can work for older Nokia phones as well if you get the right connector. Nokia chargers, like most other chargers, are nothing but 5VDC adapters without any intelligence. The phone handles all charging functions using this 5VDC supply.

  • USB cable - This can be any USB cable as long as you don't need it for anything else. It needs to have typical USB connector to connect to your laptop or desktop. Connector at the other end can be anything as it would be discarded anyway.
  • N series connector - I bought a cheap Nokia adaptor charger adaptor cable. One end of this connects to older Nokia chargers and other end connects to the handset. This is officially called CA-44
  • Wire stripper/cutter tool
  • Insulation tape
  • Digital Multi Meter with continuity tester
 Steps to follow

  • Cut the USB cable in between. You can cut it to desired length. It need not be as long as it is.
  • There would be four wires inside - Red  (+5V), White (Data+), Green (Data-) and Black (GND). You need to open insulation of Red and Black wire.
  • Cut the charger adapter cable near its female end. This adapter cable is usually shorter in length so cut near unwanted connector to get maximum length.
  • Using multimeter find out which wire connects to outer conductor of charger pin. Connect this wire to black wire of USB cable.
  • Connect red wire on USB cable to other wire of charger pin.
  • You can solder these connections or use insulation tape to properly cover up the cable. Soldering is preferable as it will make the cable less prone to accidental pulls or rough use.
  • Test that there is no short between connectors after the joint has been covered up.
  • Connect the cable to computer and phone and check. 
Enjoy your new charger :)