With I/O board free, we can focus on the fan.

This Delta electronics fan is held in place by three screws with rubber vibration damping mounts, and is rated for 5 V and 0.33 A.

A fan can be a death sentence for battery life in any portable device, so it makes sense that rumors have it that the graphics are drastically underclocked when you're undocked.

In addition to saving power by pushing fewer pixels, this ought to also let the Switch save juice by running the fan quite a bit less.