Have another 8s and 4s case on the way from Amy. This 8s one will have the wheel addition. I built my own wheeled carts for the other two stacks. This one will set lower to the ground and I will have room in the middle for one more. This will bring the number of 8s batteries to 6. Considering that the number of sun hours is on the decline in our part of the world, figured a little more storage capacity could prove helpful.