cr0m08 said:I don't know for sure, but I would think the ground connection wouldn't matter that much. Except to say that if all ground connections are common "before" the shunt (on the controller side of shunt), then the measurement of current will include all sources of power drain? So in other words, even the current of the CA itself is being measured if connected as in the pic from the ebikes.ca site? Would that be right?
Exactly correct. You can put the ground wire on either the S+ (controller side) or S- ( battery side) of the shunt. If you put it on the controller side, then the current of the CA and more importantly any accessories (like a front bike light) plugged into the CA's power tap will also show up as current on the CA screen. If you put your CA ground on the battery side of the shunt, then it won't show accessory current of devices plugged into the CA.
Most people prefer the Cycle Analyst to show the current draw from bike lights, USB chargers etc. hooked up to the CA and so that's why by default we put the ground on S+. But some prefer it the other way without this current showing up, that way when you're drawing say 500 watts you know it's 500 watts going into the motor, and not say 480 watts to the motor and 20 watts into the headlights.