You'll know more when you buy a Giant charger.Just to clarify the different opinions on CANbus.
Are we saying that with the battery removed from the bike and plugged directly into an original giant charger with the adapter that it still may not charge ?
So the charger and battery working independently off the bike will not work unless giant link them with a code ?
Because the motor , battery, charger. And so controller are all linked by CANbus software that will not let any of the parts work independently?
My Shimano bike is part of a community scheme containing Yamaha, Giant, Bosch and Shimano systems. My direct experience is mainly Shimano, but when borrowing other bikes short term with different motors, there is no worry about which charger accompanies which bike.
Bosch do some funny stuff between display and motor, @Shockwave can tell you more about that, but Giant just do a smart charger and a fast charger, no mention of any dealer intervention needed to make them work together.
I have three chargers and five batteries and two motors in my Shimano collection, any combination works. I'm pretty certain you can buy a charger, see it work and stop worrying about that aspect of the bike!