Technology progression chronicled by GM's vehicle battery packs

Battery pack on the left belongs to the Chevy Volt and the one on the right, to the ’97 Chevy EV1. The Volt’s battery utilized lithium-ion cells to produce the same 16kWhrs as the older, and 800 lbs heavy, EV1 lead acid unit. Next up: glovebox-sized units that you can swap out like a power drill pack. Okay, I just made that up, but that be sweet.

Flickr via OhGizmo