OC-3 = digital
Digital usually = high current draw
High current draw = short battery life
There's your explanation.
Digitech pedals are the most frightening examples of this. They kill batteries in a mere few hours.
Analog pedals, especially analog overdrive/distortion/fuzz pedals, tend to be the most battery-friendly pedals on Earth. But as you work your way up to complex effects and digital effects, the average current draw is much higher.