If you get enough like-minded individuals together, they can accomplish quite a lot. Take, for instance, a group of fans on the MyNissanLeaf forum who wanted a more accurate way to tell how much further they could drive their Nissan Leaf. They accomplished this goal by coding up a device that plugs into the OBD-II diagnostics port and returns the exact state of charge of the battery.
You might be wondering how that is any different than the existing state of charge meter on the instrument panel. Well, the problem with the OEM panel is that state-of-charge is shown as a 12-segement display on the dashboard. Since the Leaf's range can be anywhere from 47 to 138 miles, a single segment on the gauge could represent as little as four miles left. This lack of granularity can lead to some serious range anxiety when you are down to 1 bar and not really sure how much that bar means. Yes, there is the range output shown right besides the charge gauge, but that is only based upon your most recent driving habits, and only the driver knows what type of roads lie ahead.
With the new device, Leaf owners can see the exact state of charge as a percentage of battery life remaining, allowing them to extract every last mile without worrying about being stranded on the side of the road.