Problem is that magsafe means wireless charging which is highly unefficient. It's not that big of a deal for stationary applications, but for attaching a spare

Problem is that magsafe means wireless charging which is highly unefficient. It's not that big of a deal for stationary applications, but for attaching a spare battery (which is itself limited by its capacity) you are probably wasting 30% of it on the overhead of the wireless power transfer.