In a Daimler demonstration project, 100 all-electric Smart ForTwo minicars have been darting about London since the end of 2007. Those versions employ Zebra batteries and have about a 62-mile driving range. While they have been functioning and enthusiastically received, a Daimler engineer—who preferred not to be identified—told Hybridcars.com that the battery performance was far from optimum.
The newest version of the electric Smart, set for demonstration projects in the US and Germany, will instead use lithium ion batteries
that should give the car close to 100 miles of range. Conversion of the Smart to electric drive is relatively simple compared to most vehicles since its original design incorporates a “sandwich” floor designed to accommodate alternative powertrains. The sandwich design is also critical to the car’s crashworthiness. What Daimler calls “small series” production of the electric two-seater will start at the end of 2009.
Daimler will use the same lithium ion cells for the Smart batteries as the ones found in the company’s hybrid heavy-duty buses. Daimler sees this strategy as a way to amortize the high cost of the batteries and extend the technology. Since the buses are further along—many are in real-world service—proven technology can be scaled down to Smart. Most of the industry is going in the opposite direction—trying to scale up lithium batteries for cars from use in small electronic devices.
The batteries aren’t the only anticipated change in the electric Smart. If and when the electric minicar comes to the US, Daimler is likely to move away from the “Smart ED” name. The letters “ED” are likely to draw a blank for American consumers. The more common “EV”—for electric vehicles—is better known (although mostly to fans of battery-powered cars).
The new generation of Smart EDs could also have new high-tech gear: an onboard charging unit that communicates with a charging station. This could be put to test in the upcoming Berlin deployment, conducted in conjunction with the German utility RWE. According to Daimler, the new charging unit will ensure that the battery is automatically charged with low-priced electricity when the network is not used to full capacity, for example at off-peak times. In other words, the Smart could come equipped with a “smart” charging meter.