The Issues On Battery Encasement Safety Continues

Electric car made from batteries
Electric car made from batteries

The recent tsunami disaster in Japan has not only brought adversity to the Land of the Rising Sun, but it has also provided insight into one of the brightest spots in the car industry today, Nissan’s all-electric Leaf.

Nearly two dozen Leafs were caught in the tsunami wave that devastated the region after the earthquake. The electric cars were recovered and the observations gleaned have provided Nissan a distinct advantage in the safety of their Leaf. Not a single one of the cars caught fire as their batteries remained intact, encased in an airtight steel exoskeleton. Aside from this, the battery array was surrounded by two more layers of protection to keep the 660 lbs battery array completely safe even in disaster situations.

According to Bob Yakushi, Director of Product Safety at Nissan North America, “Considering how they were tossed around and crushed, we think that is a very good indication of the safety performance of that vehicle.”

This design decision of encasing the battery pack of the Nissan Leaf in steel may be the reason why federal investigators are not as keen on investigating post crash fire risks in the Leaf as compared to the Chevrolet Volt. The Volt’s battery array is placed on a T-shaped tray with a plastic cover.

This design has been much criticized after batteries from the Volt used in crash tests caught fire under the auspices of the National Highway Traffic and Safety Administration. This has lead to a formal investigation as to the safety of the Volt and defects are now being scrutinized.

The Leaf though was not spared the inquiry as the Volt did. For its part, the NHTSA said that the Leaf and other electric vehicles “had not raised safety concerns about other vehicles other than the Chevy Volt.”

The reason for such design, according to a spokesperson from GM, Robert D. Peterson, was to use a cover that did not conduct electricity, hence the choice of a plastic cover. Other carmakers though have taken Nissan’s lead in putting a steel structure around the batteries, such as Ford with its Focus electric compact car version. This decision for the Focus though was made long before the safety issues with the Volt were known to the public.

The Leaf also does not have a liquid cooling system, which the Volt has. According to Nissan, laminated circuitry reduced the heat produced in the batter array. The Focus and the Tesla Roadster have liquid cooling systems for their batteries. Tesla for its part though has enclosed each battery pack’s cells in steel for protection and heat dissipation purposes.