Berkeley, Calif.

WITHIN weeks of when Nissan first began delivering the Leaf to buyers last December, do-it-yourselfers were looking for ways to make the new electric car — an engineering marvel from one of the world’s leading automakers — even better.

Among those who applied their 21st-century engineering skills to tinkering pursuits that date to the dawn of automobiles was Gary Giddings, 69, a retired engineer and a passionate supporter of electric vehicles.

“At this point in my life, my goal is to spend whatever time I have trying to help E.V.’s become successful,” Mr. Giddings said. He is using his Ph.D. in electrical engineering, earned at the University of California, Berkeley in the free-speech 1960s, to correct some of the Leaf’s shortcomings and to squeeze more performance out of it.

Mr. Giddings and a dozen or so Leaf-driving eco-enthusiasts quickly focused on a glitch that annoys many Leaf owners: a battery-charge gauge that is notoriously untrustworthy. This dashboard readout can mislead drivers into believing that the battery pack is about to run out of juice when in fact there are plenty of miles left in the electricity tank.