Power is the limitation that limits the parts (weapons and gadgets) that you can attach into the chassis.The power capacity is depended on the chassis.More-stared chassis often has more higher power capacity than low-stared chassis.For example,you cannot attach a 8 power chainsaw into a chassis with only 7 power capacity.The amount of power used by parts is stacked.
There are only two ways to increase the power capacity of the chassis,either fuse the power toolboxes into the chassis,or upgrade the skills that gives extra power capacity to certain chassis.
1 star chassis is not recommended because power is less.
5 star weapons are also not recommended because they occupy much power.