I got a Canon Speedlite 430 EX II just a couple of weeks ago and noticed a surprising and annoying feature: If I leave batteries in the flash unit, even with the flash switched off and removed from the camera, the batteries will be dead in a day or two.
This happened to my twice with the expensive Energizer Advanced lithium batteries, so needless to say I was unhappy. But most devices I can leave the batteries in, and it won't drain much as long as the power is off. Is it something I am doing? Or perhaps there is something is wrong? What would be draining the batteries in this case, and is it normal?