I’m trying to use LED’s in a Halloween project. I have several fairy light strings that each contain 20 tiny LEDs. When purchased they were provided with twin button cell power modules. Each contains two 2032 button cells for a 6 V power supply. I have a lead acid 12 V battery I want to use to run the entire project. I have several 12 V programmable light strips and want to power the fairy lights also at 12 V. I do not have specs for the Individual LEDs in the light strings. I do know the entire string runs at 6 V as I said and I know the current the entire string draws. There are two colors one string green one string purple they draw current differently. How can I calculate the current limiting resistor so I can replace the 6 V or two button cell power supply with a 12 V power supply. Any help would be gratefully appreciated.