It probably won't though I have been screwed a couple times when my USB power brick tried to charge itself off my phone because I hadn't pushed the button to switch the port from drawing power to delivering power.
Is there some sort of protocol in USB-C for two devices with batteries to negotiate which should charge the other. Though I imagine the iPad could just refuse to deliver the high power states/not have the circuitry.
Doesn't the Macbook require a certain minimum power to be available before it will start trying to charge though. IE if I plug it into an old .5A USB charger would it try to charge off the 2.5W? That's most of what I meant when I was talking about providing enough power.
Is there some sort of protocol in USB-C for two devices with batteries to negotiate which should charge the other. Though I imagine the iPad could just refuse to deliver the high power states/not have the circuitry.