What happens if you're connected to something that can't deliver 26 amps? Does it take what it can from the wall, and the rest from the battery?
I'd suspect yes.
I would bet that just about everything is run FROM the battery pack... and the chargers simply replenish that reserve. If the charger is supplying that energy "real time" at the same rate as the draw, then it's largely academic... you might as well say that the load is being supplied by the shore power.
It's a giant laptop, really.