Originally posted by GUB When I had a hopelessly mixed set of rechargeable AA batteries I tested them by buying a budget single battery analogue clock. I parallel wired a torch lightbulb into the clock circuit as a load. I set the clock to 12 and then saw how far it got. Worked great but I don't know if it would adapt to the higher voltages of the camera batteries.
Could be worse for a battery, because it may get deep discharged and damaged. The ,method to measure the loaded Volume of a naturally empty battery is much better and reliable