I need a bit of help here guys :D I have a something here that's effectively a battery that can supply around 1.5V I believe at a few micro-amps to a few milli-amps for an unknown amount of time. The problem is.... they are all infact unknown quantities and I want to figure out what this batteries capacity is. I hear that the way battery companies measure their batteries capacities are to drain a battery at a fixed current until the voltage reaches "terminal voltage" and they use that time in hours to determine the capacity by multiplying the current draw and the time it took to drop down to terminal voltage. Now the problem is theres no information given on how they actually do that and I was wondering if anyone know how to create the circuit necessary to draw a constant current so I can determine the capacity. If anyone knows what this "terminal voltage" is as well, that would be helpful to know :) Thanks!