Power Arduino with a cellphone

Step 3 Connect the charger

Cut of the connector off the wall wart. Check which wires are positive and negative by plugging in the wall wart and using an led to test. For me the wire with the white bad was positive and the other was negative. strip the connectors wires. Now you can either solder the negative wire to the gnd terminal on the connector or strip some insulation off the middle of the negative battery wire and solder it to that. I did the second choice. Then solder the positive wire to the empty terminal on the connector in between the 2 other wires. This one goes to 5v on the arduino.