On older models there is no way to select a different charge speed, it will always attempt to use the fastest available (16,10,6)
If the newer models allow you to limit the charge (do they, is there a setting??) then this would likely be the limit for all connections - the car can not tell the difference between the 13A evse Brick and a charging post. they both use the same EVSE protocol.
Under the EVSE Protocol the allowable charge rate is controlled at the Post or your connecting cable, or the EVSE brick. some cars can also set another limit on top, (I don't know if newer Amperas can or not?).
Contrary to what Parax says, the newer models have a setting for 10A or 6A, and the ”brick” does not have a switch on it, but the car charges at 16A with a dedicated charger (nothing special about the charger AFAIK). So somehow the car knows whether it is the brick or not - I guess if the charger says its max is less than 16A then the car assumes the brick. So the answer is yes it should charge at 16A if the charger is capable of that.
I'm happy to be corrected, I can only speak for the older version..
I'm interested in how the car knows its on a brick rather than a post? Maybe it assumes all 10A chargers are bricks?Though I guess it's not beyond GM to do something different..
On mine (June 2013) you select the charge rate 10A or 6A from the car and it specifically says on the display that this only relevant for the GM supplied brick - there is no selection on the brick itself anymore (i understand there used to be a switch?). When you plug in to a dedicated wall charger (home or public) it will use 16A regardless of your setting for the brick. (in fact my home charger is 30A capable but will still only use 16A - it has a dialogue with the charger and just knows!).
The way to look at this is actually simple if you don't try to over complicate it.
First and foremost, regardless of where the charge rate is set (brick, car), it is the car that determines the charge rate used. As soon as you realise that it becomes a lot easier to understand.
The car will choose to charge at the lowest rate of...
- rate set in car (for newer models)
- The setting on the brick (for older models)
- The rating of the type2 cable (16/32A)
- The rating of the post (16/32A)
So, for example...
- If you set 16A on the car but plug in using the brick it will charge at 10A (or if using an older brick with the switch 10/6A)
The car doesn't know it's a brick. What it knows is that the EVSE into which it is plugged is 10A. That comes from the charge controller in the brick. When you plug into a 32A post the car knows that the post could deliver 32A from the charge controller in the post.
It doesn't actually "default" to 6A - you make the selection on the in car menu and it remembers it for ever (unless you one day change it back to 6A). So in that sense if you set it to 10A once upon a time and leave it and plug in as you describe above it will "default" to 10A if you see what I mean...