The automaker created an entirely new set of tests for the Leaf.

Automakers typically run all new models through a whole series of safety- and quality-related tests. This serves to ensure that everything works as it should before a car is put into the hands of the general public.

When Nissan was developing the Leaf it ran into a problem: many of the tests that new models routinely go through are designed for gasoline-powered cars, not for electric cars.

Nissan's Technology Development Division, led by Kouji Tanaka, was given the task of developing a new set of tests that would push electric vehicles to their limits.

The team brainstormed and came up with about a thousand hazardous scenarios that Leaf owners could potentially encounter on a daily basis.

"We created new tests after considering how the car would be used by drivers, the potential weaknesses in the parts and the environment outside the car," said Tanaka.

The tests included deliberately creating short-circuits in the Leaf's drivetrain and pouring highly-conductive liquid over the seatbelts.

Nissan engineers also talked to potential Leaf buyers to find out what their biggest worries were.

"Our customers are most concerned about electric shock, leaks on rainy days while charging up and what happens if the car drives through a puddle," said Tanaka.

To reassure would-be buyers Nissan drove the Leaf at a relatively high speed through deep water. The company also poured water on the Leaf's plug while it was charging.

When all is said and done, the Leaf was put through twice the amount of tests that gasoline-powered cars normally go through.

Developing the new tests was a timely and costly endeavor but they will be used again on future Nissan-badged electric vehicles.