Capacitor smoothing question

Author	Message
Volhout Guru Joined: 05/03/2018 Location: Netherlands Posts: 5919	Posted: 01:03pm 10 Mar 2025         Mixtel90 said   No, you misunderstood. :)  I meant that using a simple resistor as a load is inaccurate for primary cells. Rechargeable cells usually have a much shallower discharge curve, although some lead-acids can be a bit iffy as they age. With a shallow curve a resistor has much better accuracy as the start and end currents don't vary by all that much. Hi Mick, As long as the resistor is a constant value (we are not measuring the resistance) it is absolutely usable as an accurate sink. We know the voltage at any time (that is what we measure), so we also know the discharge current (ohms law). So with every measurement we discharge the battery with a known quantity (not the same all the time, but known value), so we can calculate accurately what the cells capacity is. It may take 7 hours, or 8, or 10... doesnt matter. We know exactly the capacity... twofingers project Volhout Edited 2025-03-10 23:41 by Volhout