[Solved] 5DII serious battery drain after UNinstalling ML

[mes]

Recently installed ML to my 5DII, everything seemed fine. Since it is said to use more power for standard photo mode and I do not need the extra functionality at the moment, I uninstalled ML by disabling the boot flag via the firmware update dialog and then formatted the card. Contrary to the instructions, I did not reset all the settings custom functions - well, at least not immediately (and I hope that is not why I am having this problem).
Since then, the battery drains extremely quickly when the camera is powered off. A new and fully charged battery is drained within 2-3 hours. Tried several batteries, no difference.

When I noticed that, I tried using a different memory card, no memory card at all, waiting before removing the card (of course), resetting the camera settings and custom functions via menu, reflashing the Canon firmware (2.1.12), resetting the camera by removing the battery and the clock battery and waiting for a few hours, using different lenses or no lenses at all and reinstalling ML. I also checked and cleaned the battery and memory card compartments. Nothing helped, the battery still drains - with both the the official Canon firmware and ML. But only when powered off, it does not when in standby/auto power-off.

I'm beginning to run out of ideas. Does anyone have a suggestion how to solve this problem?

[Walter Schulz]

According to Canon "reflashing" firmware with the same version will do nothing at all. Use EOS Utility and downgrade to a version prior to 2.1.12 and upgrade to 2.1.12 thereafter.
Evaluate if your problem persists.

Ciao, Walter

[g3gg0]

Contrary to the instructions, I did not reset all the settings custom functions - well, at least not immediately (and I hope that is not why I am having this problem).
Since then, the battery drains extremely quickly when the camera is powered off. A new and fully charged battery is drained within 2-3 hours. Tried several batteries, no difference.

it's quite impossible that ML caused smth like that.

can you use a battery adaptor and measure the current flow caused by the camera using an amperemeter?

[mes]

Thanks for the responses!

Just after posting this thread, I uninstalled and reinstalled ML again. Since then, the drain seems to have stopped. I have removed ML again and everything seems back to normal. No idea what exactly it was that caused the drainage and what stopped it, but so far everything looks fine again. I might try to recreate this phenomena at a late point in time and try to  find out, but I rely on my camera for the next few weeks.

One oddity I noticed: When the batteries were draining, there was one single battery that caused the red light by the CF slot to blink continuously when the camera was turned off. As it was a new cheap third party battery I had not yet used before, I dismissed it, assuming that the battery was broken. However, it does not cause the blinking any more now and the battery works as it should.