Electric Car Battery Technology: A Comparison
Up until recently, battery technology has been one of the primary hindrances for advancement in electric vehicle innovation. In the past, electric vehicles typically capped off around 60 miles per charge, relegating them primarily to simply "commuter car" status. Two of the recently hyped "top of the line" model electric cars, the Lightening G.T. out of Britain and the U.S. built Tesla Roadster, each use a different battery technology which promises marked improvement in both battery power and range. And, naturally, each company proudly boasts that the battery design they have included in these new, suprisingly classy electric vehicles, is superior.
Beneath their fine, carbon-fiber exteriors, the Lightening and Roadster models each utilize different methods of sucking power and speed out of batteries. Although both systems appear to have successfully tackled some of the issues that have been limiting factors for electric car battery technology, the jury is out as to which system (if any) is superior. We've gathered a bit of information about each design as follows, so you can formulate your own opinion.
The Lightening G.T.'s "NanoSafe" Battery System
In the year 2000, a U.S. company out of Reno, NV, named Altairnano, Inc., established a research program to create an ultra safe, high power battery using cutting-edge Nanotechnology. The result of their hard work is the "NanoSafe" battery. In the NanoSafe battery, the graphite anode is replaced with one made of lithium titanate nanoparticles. The firm claims that its batteries are not only safer (graphite can burn; lithium titanate cannot), but can also be recharged more rapidly. Using a 480-volt outlet, such as might be found in a roadside service station, the job should be done in ten minutes.
Here is a brief summary of some of the claims made by the manufacturer regarding the design performance of the NanoSafe Battery:
- NanoSafe batteries have a significantly large life expectancy in excess of 12 years, versus the 3-5 year usable life of other batteries. NanoSafe can retain up to 85% charge capacity after 15,000 charges.
- NanoSafe batteries are more thermally stable due to the use of nano titanate materials instead of graphite, and there are no toxics or heavy metals used in the manufacture of NanoSafe batteries. As a result, they are claimed to be "safer".
- The NanoSafe batteries are designed to be used in vehicles and hostile environments and will work in temperatures between 75°C and minus 30°C. Unlike standard Lithium-Ion batteries in electric vehicles these don’t need to be kept cool when charged/used or heated to get them to perform in sub zero temperatures.
- Each NanoSafe battery unit is about the size of a large car battery and thirty such units make up a complete battery pack. These are situated in the car to give the desired ultra low “center of gravity” and optimum weight distribution in both front and rear of the vehicle.
- The Lightening's 30-battery pack boasts a range of over 185 miles and take only 10 minutes to recharge.
The Tesla Roadster's Lithium-ion Energy Storage System
Tesla's Energy Storage System utilizes several thousand lithium-ion cells, which, due to their high energy density, provides exceptional energy-to-weight ratio and capacity for hundreds of charge and discharge cycles. As Lithium-ion batteries are becoming increasingly favored in the industry, this kind of battery uses lithium in its ionic form (that is, with the atoms stripped of an electron to make them positive). When the battery is fully charged, these ions hang around one of its electrodes, the anode, which is usually made of graphite. During operation, the ions migrate within the battery from this electrode to the other one, the cathode, and electrons (which are negatively charged) pass between the electrodes through an external circuit. It is that current of electrons which drives the motor.
Here is a brief summary of some of the claims made by the manufacturer regarding the design performance of the Lithium-ion energy storage system:
- Even with the demands of charging and discharging the battery pack on a daily basis, the batteries in the Tesla Roadster will give you more than 100,000 miles of peak performance driving. After that point, the battery will see only "gradual" drops in performance over time. I guess what that really means may be anyone's guess.
- The battery stores enough energy for the vehicle to travel about 220 miles without recharging, something no other production electric vehicle in history can claim thus far.
- It's light, durable, recyclable, and it is capable of delivering enough power to accelerate the Tesla Roadster from 0 to 60 mph in under 4 seconds. Unlike other batteries that came before them, Lithium ion batteries are classified by the federal government as non-hazardous waste and are safe for disposal in the normal municipal waste stream. (but designed to be recyclable).
- Plug your Tesla Roadster into its at-home High Power Connector unit, and you'll be fully charged in about 3.5 hours. Tesla considers this a "worst case" for a consumer starting with a completely dead battery. Even after a 100-mile trip, you can be completely charged in less than two hours. And should you need to charge on the road, packed away in the trunk is an optional Mobile Connector that lets you charge from most standard electrical outlets while away from home.
- Regenerative braking — which recovers and stores the energy usually lost when you slow down — extends your charge even further, delivering higher miles-per-charge on in-town driving. Think of it like engine braking with a bonus. Whenever you slow down, you send a charge back into the battery. It's a much-needed silver lining to red lights, traffic jams, and other slowdowns.
In summary, both of these ground-breaking electric vehicles appear to be significantly more efficient than any others to date, but at a base price of $109,000 for the Roadster and a target price of $240,000 for the Lightening not particularly practical for the average American household- yet. Before the majority of the population can jump on the battery-powered bandwagon much cheaper, less-élite models will have to be developed.