Not sure about the pedal board problem, However I have found that if theres a cable in both the input and output of the pedal it drains the power. Regardless if the cables are connected to anything else such as the amp.
My advice is if your not using the pedals make sure they arnt plugged into anything.
Some boss products do tend to eat battery life though, not sure about single effects but my multi effects did, aswell as my friends micro recorder.
Hope this Helps.