Battery Breakthroughs and Issues

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In a breakthrough discovery, German scientists have developed a new fluid that can assist in cooling the large and expensive batteries of electric cars. The benefit the discovery provides is the extension of their service life and one more step in the improvement of the cost efficiency of electric vehicle transport.

The fluid has been named as CryoSolplus and has the capability of greater heat absorption compared to air or water. This would allow for tighter packing of batteries according to the research team of Fraunhofer Institute for Environmental, Safety, and Energy Technology located at Oberhausen, Germany. 

The battery pack would generate nearly 45 degrees Celsius of heat on a regular day. Its best working ambient temperature is between 20 and 35 degrees and under those conditions, the battery would only be able survive half of its actual service life. With the cost of the battery pack nearly half the total price of the vehicle, finding ways to extend its service life has become imperative for many research and development teams.

Current technologies only use air to cool battery arrays or there are no cooling systems at all. Air is not a very efficient heat absorber and requires space in order to travel in between heat generating battery arrays. Water on the other hand, is a heat conductor but requires a storage tank to be effective.

CryoSolplus consists of water, paraffin, anti-freeze and a stabilization agent, according to the research team. It has three times as much ability to absorb heat compared to water, thus requiring a smaller storage tank, creating more space and weight savings for the electric car manufacturer. The research team says that the solution and the cooling system would cost just a little over 100 euros in the manufacturing process. When heat is absorbed, the solid paraffin droplets melt and store the heat. When the solution cools, the paraffin droplets solidify.

This technology may be too late for Fisker Automobiles Karma, as it issued its second recall when two mysterious fires again hit the government subsidized electric vehicle. According to Fisker spokesperson Roger Ormisher, “Fisker engineers and an independent fire expert had identified the root cause of a fire that engulfed a Karma parked outside a Woodside, California grocery store last August 10.” He added, “The investigation located the ignition source to the left front of the Karma, forward of the wheel, where the low-temperature cooling fan is located. The final conclusion was that this sealed component had an internal fault that caused to fail, overheat and start a slow burning fire.”

Fisker has since announced a voluntary recall “with respect to this cooling fan unit” and stated it has already coordinated with its retailer. Unfortunately, the cooling system development may have come too late for Fisker.

NHTSA Closes Volt Investigation

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Last Friday, federal safety regulators have formally closed their investigation on the fires that occurred with the Chevrolet Volt. The report found no evidence of a defect and the plug-in vehicles posed no greater fire risk as any other vehicle on the street meeting an accident.

Despite the favorable results, the main problem would be rebuilding consumer confidence in the vehicle. In the larger picture, the safety concerns regarding the reliability of electric vehicles can hurt the advancement of electric cars in the automotive market. According to many industry experts, while the fires were unfortunate, it was good it occurred within testing facilities but these create chilling effect to the interest of the general public to accept new technologies.

The National Highway Traffic Safety Administration also released for the first time photos relating to the aftermath of the Volt catching fire last June. This fire occurred in a remote area near Burlington, Wisconsin and was discovered after it had burned itself out. Also included in the release are videos as to the November testing, where it showed a firefighter fighting flames in a wooden shed where two Volt battery packs were placed under observation.

The two month long investigation undertaken by the NHTSA found that “no discernible defect trend exists”. It also added that the modifications proposed by General Motors are more than sufficient to reduce the possibility of a fire occurring during an accident.

The agency further added, “Based on the available data, NHTSA does not believe that Chevy Volts or other electric vehicles pose a greater risk of fire than gasoline powered vehicles. Generally, all vehicles have some risk of fire in the event of a serious crash.”

The final safety report from the federal agency on the Volt investigation further disclosed the fire on a third battery pack last December 12, six days after the battery was exposed to coolant from the Volt’s liquid cooling system. This pack was one of the six arrays tested to study the conditions that resulted in the June fire. This December fire had consumed a Volt and three other vehicles that were also located nearby in the testing facility.

For its part, General Motors issued a statement, “NHTSA’s decision to close their investigation is consistent with the results of our internal testing and assessment. The voluntary action that GM is taking is intended to make a safe vehicle even safer.”

Another issue is now brewing on the horizon regarding the fires to the Volt. GM’s CEO, Daniel F. Akerson is set to testify before a House subcommittee hearing into why the NHTSA waited until November to disclose the June fire. Speculation has been growing that the delay in the announcement was due to pressure from the Obama administration to hide the fires because the government owns 26 percent of the carmaker.

Formal Review Of Chevy Volt Batteries Undertaken

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Federal safety regulators have instituted formal defect inquiries into the Chevrolet Volt. This move was a result of a second battery fire with the vehicle after a crash simulation.

Informal examinations were conducted on battery arrays of several plug-in cars since a Chevy Volt had caught fire after being damaged in a government crash test. This time around, a Volt battery pack was intentionally damaged as part of the testing of the National Highway Traffic Safety Administration.

A further complication occurred during the testing when there was a temporary temperature increase in another battery pack a day after it was damage. A third battery pack began to smoke and emit sparks after it was damaged and then turned upside down to simulate a roll over crash.

In an official statement, the agency said, “The NHTSA is not aware of any roadway crashes that have resulted in battery-related fires in Chevy Volts or other vehicles powered by lithium ion batteries.” It does add, “However the agency is concerned that damage to the Volt’s batteries as part of three tests that are explicitly designed to replicate real-world crash scenarios have resulted in fire.”

The NHTSA clarified though that the battery tests it is conducting has not raised any safety issues about the batteries in other plug-in cars. It added, “Chevy Volt owners whose vehicles have not been in a serious crash do not have reason for concern.” The new testing to be done includes damaging the battery compartment and rupturing the coolant line.

For its part, General Motors unveiled the Volt to the public last year and said it was not surprised by the current investigation being conducted. The carmaker though insisted that there were no defects in its Chevy Volt and has been working with the agency in order to replicate the conditions that brought about the fire last June. The report on the June fire was only made public last month and there have been no other similar incidents except during the testing conducted.

According to Jim Federico, G.M.’s Chief Engineer for Electric Vehicles said “The Volt is safe and does not present undue risk as part of normal operation or immediately after a severe crash. G.M. and the agency’s focus and research continues to be on battery performance, handling, storage and disposal after a crash or other significant event, like a fire, to better serve first and secondary responders. There have been no reports of comparable incidences in the field.”

G.M. said the June fire was due to the failure to deactivate the battery, which occurred at a crash test in a storage facility. They believe that crystallized coolant has leaked out of the cooling system of the battery array and pooled in another area in the pack when it was rotated during the simulation crash. A month later, G.M. began publishing post-crash safety protocols to emergency responders, saying that the battery needs to be isolated from the rest of the vehicle through a disconnect switch then later on depleted by the company.