A 3.6V battery was used in cell phones a long time ago when the battery was three Ni-Cad or Ni-MH cells that charged to 4.2V.
Now cell phones use a 3.7V lithium battery cell that charges to 4.2V.
The charging circuit is inside the phone. The simple power supply is not a charger.
Most cell phones use a battery charger IC that has its schematic on the datasheet.
Charging circuits for cell phones or anything else can be quite simple or very complex. Follow the attached link for several battery charger circuits. They may or may not have a 3.6v battery model, but the changes needed to the circuits should be fairly straight forward. If you don't find what you need, do a Google search for "cell phone battery charger schematic" or
"3.6V NiCad battery charger schematic". Also, for more hits, you can try replacing the word "schematic" with the word "circuit". If you still strike out, reply and I'll try to help you.