I've done a search but cannot find any threads.

After owning and using 10 dSLRs over the years, many of which use the same batteries, I have accumulated quite a few BP-511(a) batteries. Most of them are Canon, but a few cheapies that came with 3rd-party grips as well.

I want to test them all to see how well each holds a charge (and then mark them somehow), but it seems like a real waste of time and shutter actuations to charge each battery and rattle off shots until the battery dies.

Does anyone know if there is an easy, effective way to test BP-511(a) batteries?

Don't use your camera and add needless shutter actuations. I would suggest hooking them up to a 12 Volt light bulb and seeing how long it takes to discharge.

Thanks for the reply. I wonder if discharging the batteries with this method would damage them (maybe cause them to over-heat?).

Maybe I should revise my question and ask whether anyone knows a safe, effective way to discharge the batteries completely and monitor how long it takes. I have two new Lenmars that I'd like to drain and re-charge a few times before a wedding on Sunday as well as the testing I'd like to do on some of my genuine Canons.

I built a constant current battery tester many years ago. Basically you need to choose a reasonable discharge rate depending on the type of cell(s) and then make sure that the cutoff voltage is above the safe limit for the number and type of cells. Record the time from start to cutoff with a digital timer, so you don't sit around watching it.

EBH