Introduction: 18650 Battery Charger, Transformed From Galaxy S Charging Cradle

About: an electric engineer with State issued license

It's a simple work to transform Smart Phone Charging Credle to a 18650 Li-Ion Battery Charger as following steps.

1. Remove label of the back side and unscrew 2 screws with Philips #1 Screw Driver.
2. Open the slicing cover and remove it - just apply force to untrck.
3. Cut away about 17mm of top halves like photo.  Cut a bit more edge side to fit in the 18650 Battery. I have used 4" Angle grinder for rough cutting, trimmed with cutter and finished with files.
4. Provide a negative terminal, possibely a spring metal but good normal >0.5mm tin plated steel sheet.
5. Make V cuts(@4 places) bottom side for heat-and-push-in with soldering iron.
6. Provide positive terminal in proper size and glue to the proper position. I have used a piece of sponge double side tape.
7. Soldering positive terminal to B+, negative terminal to B- and a 1.5kOhm 1/4W resistor between sensor terminal(middle) and B-.
8. Apply a piece of masking tape, not to make short circuit with the resistor.
9. Assemble it.
Remarks:
a) Because of the lost of one coupling part of the two halves, cutted side would be loose - apply a drop of super bond to secure it.
b) The 5V supplying micro USB connector should be connected after installation of the 18650 Battery. - Because of the soldered 1.5kOhm sensor curcuit, we are cheating the circuit.

The charger works perfectly because the similarities of the battery capacities, Gallaxy S and 18650.