The Tesla Roadster is the first all-electric car to rely on lithium ion batteries. But these batteries, which have the highest energy density of any battery available, are also prone to overheating. How has Tesla addressed this potential problem?
According to the Tesla website’s “how it works” page, “The system addresses thermal balancing with a liquid cooling circuit. Multiple passive and active safety devices ensure safe operation over the wide range of driving environments and scenarios. An array of sensors and a dozen microcontrollers communicate with the vehicle to allow efficient use and management of the battery pack. Finally, the entire assembly is housed in a rugged enclosure, which protects the system from the harsh road environment while supporting the internal components.”
It’s interesting that advancements in battery technology that are leading us towards all-electric battery powered cars have come as much from the laptop computer industry as from the hybrid automobile industry. The computer press is a good place to turn for more about the lithium ion battery. A good article on the website ZD Net Asia “Can Anything Tame the Battery Flames?” offers several insights. They boil down to this “…manufacturers have continued to increase the energy density–or the amount of energy the battery can hold–of lithium ion batteries by thinning out separators (which keep the electrodes apart) and changing other components. These changes lead to longer run times–something consumers are demanding–but also raise the potential that something can go wrong.”
You can find discussions on the Tesla Roadster at Future Pundit, or Washington Monthly. From these posts many good points emerge, including the following two:
Nickel Metal Hydride battery heat management and load management is highly evolved and, at least right now, hybrid batteries using NMH technology are safe and cost effective. With some hybrid taxis now having logged over 200,000 miles, to-date not one hybrid battery pack has been replaced due to battery degradation. And the replacements that have been made, because of damage from accidents, only cost about $3,000.
Lithium Ion batteries are still a risky technology to use in automobiles, and Tesla evidently is banking on rapid advancements in their longevity and their safety. Currently the Tesla battery pack is only rated for 500 charge/discharge cycles, which isn’t nearly enough. The nickel metal hydride battery packs in hybrid cars can easily turn in 5,000 cycles.
Tesla Motors has done one thing very well, they have put to rest the common misconception that electric vehicles are anemic, oversized golf carts. And Tesla is just the most recent and visible embodiment of a gathering momentum both politically and technologically towards cars that use renewable energy and don’t pollute. Greener cars are coming.