Canon vertical grip on/off button - Does 'on' drain battery?

[buurin]

Does leaving a vertical grip in the 'on' state drain the battery?

I am under the impression the switch simply disables the buttons on the grip.

I have 3rd party grips (opteka & meike) but I assume they behave the same as the Canon.

Thanks

[cdifoto]

On for the grip just activates the buttons.

[DDCSD]

The status of the on/off button should have no effect on the battery, assuming that there is no defect in the grip (stuck button or similar). You are correct that it simply disables the buttons.