@rdtsc I am wondering if you can answer a question I have. I have 2 18650 Lithium Ion cells in series. 1 charges to 3.18 Volts and the other charges to 4.20 Volts. Of course these types of cells are not well tested. Hence the variation in cell health. 3.18 Volts isn't a healthy cell. 4.20 volt cells are healthy cells.

@rdtsc The 3.18 Volt cell has a capacitance of 2,000 mAh and the 4.20 Volt cell has a capacitance of 2,200 mAh. What is the full capacitance?

@rdtsc I changed the battery size and capacitance that came with my 5 Watt laser. Which has actually turned out to be 5.25 watts and not just 5 watts. Surprisingly 1,300 mAh battery capacitance only lasts 4.5 minutwe on runtime.

@rdtsc I know that the capacitance will be affected by the other cell not having the same charged voltage. So I can't just use a formula or simple math to figure out the capacitance

@ScientistSmithYT No more than 2000mAh. Once the lowest capacity cell is discharged, further operation will push current from the still charged cell through the discharged cell and destroy it.

Battery capacity in parallel adds (more or less.) Battery capacity in series is limited to the capacity of the smallest cell.

What JRE said. :) Also do not use the term "capacitance" when referring to a battery's potential energy. "Capacitance" is a physical characteristic of capacitors (electric field), while "capacity" is measure of a battery's potential electric charge. Both move electrons in a similar way, but stem from a fundamentally different physical principle. Caps = Capacitance, Batteries = Capacity.

Happy Friday! Almost no more work this week.

@JRE Ok thanks :)

@rdtsc Oh, ok got it Thank you for correcting me. :)

@JRE I got another question. When I have a circuit that is powered by a battery. And in that circuit I have a resistor in series to the load. Given we use ohms law. We calculate using the current and voltage. A certain wattage or power is dissipated in the resistor. When we use the formula for watts in place of voltage. The voltage it gives us is the output voltage correct?

@JRE The reason I ask such a dumb question is because I'm having a brain fart right now. And I need to figure it out within the hour. I think it does and then I think it doesn't. So I've got myself confused.