First I think we should acknowledge that the range extender exists in nothing but a graphic created in a Tesla design studio desk. In fact, I do wonder if it was thought of in just the last few weeks before the reveal, as the range was not what they had promised. I understand they don't plan to even ship until the end of next year, so, probably no design yet. Perhaps with this discussion we can help them make some decisions!
Simplest option. Have a 240 volt output that connects, via the on board 240 plug, to the charger. That is already acknowledged to provide bidirectional charging. Can it be used while driving? Can it only be used when we stop (to charge the battery)? Certainly the current transfer rate will be relatively slow so it will have to be active at any time the vehicle battery is less than whatever the maximum setting is. Even then, it might not keep up when one is pulling a heavy enough, or aerodynamically challenging enough, trailer.
Best option. Have a dedicated connection that links directly to the high voltage battery. This would allow the greatest transfer with the least amount of trouble. It will still require sophisticated circuitry to ensure that one doesn't get a gigantic arc when connecting the two batteries together. So, in that sense it's not as good as the simpler method above, since it requires creating more circuitry. This would also seem to be the method that would make it most likely to be able to use this range extender pack as a substitute power wall. Or at least in conjunction with some existing power walls.
Horrific option. Have a cable that runs from the battery to the charge port connector. Maybe even use the portable charge connector to do this. Clearly this would make for some interesting difficulties while driving, but might still work. Certainly hope they don't go this way!
What am I missing? Do you think Tesla has even thought this far yet? Certainly seems like a rushed solution. Although, I actually think it's a good one. Especially if they devise a way for us to easily use it for backup power for the home, when we don't need it in the vehicle. It could even be made with cheaper LFP batteries.
Simplest option. Have a 240 volt output that connects, via the on board 240 plug, to the charger. That is already acknowledged to provide bidirectional charging. Can it be used while driving? Can it only be used when we stop (to charge the battery)? Certainly the current transfer rate will be relatively slow so it will have to be active at any time the vehicle battery is less than whatever the maximum setting is. Even then, it might not keep up when one is pulling a heavy enough, or aerodynamically challenging enough, trailer.
Best option. Have a dedicated connection that links directly to the high voltage battery. This would allow the greatest transfer with the least amount of trouble. It will still require sophisticated circuitry to ensure that one doesn't get a gigantic arc when connecting the two batteries together. So, in that sense it's not as good as the simpler method above, since it requires creating more circuitry. This would also seem to be the method that would make it most likely to be able to use this range extender pack as a substitute power wall. Or at least in conjunction with some existing power walls.
Horrific option. Have a cable that runs from the battery to the charge port connector. Maybe even use the portable charge connector to do this. Clearly this would make for some interesting difficulties while driving, but might still work. Certainly hope they don't go this way!
What am I missing? Do you think Tesla has even thought this far yet? Certainly seems like a rushed solution. Although, I actually think it's a good one. Especially if they devise a way for us to easily use it for backup power for the home, when we don't need it in the vehicle. It could even be made with cheaper LFP batteries.
