Hi keezee, Welcome to DC.
In my opinion, it might be using a bit more power to get up to the temperature required. But once there I should imagine the slow cooker/crock pot is designed to hold that temperature using a lot less power than if it were on the stove top (hob) or in the oven.
Have you noticed it just at the beginning? or does the meter seem to continue through out the entire process?
Again, it should probably fluctuate, high at the beginning, then less, coming on sporatically to keep the temperature.