You may remember that last August, we broke the story that what is now called the 2014 Cadillac ELR electric coupe got the green light for production by GM's overlords.

An abashed GM confirmed the story a few days later and released the name of the new model, known until then as the Converj concept car.

Now, we learn via GMInsideNews that another anonymous source says the ELR will enter production roughly 18 months from now at the same Detroit-Hamtramck Assembly plant where the Chevrolet Volt is built.

Production will begin, GMI's source says, late in the 2013 calendar year--compared to some recent GM models that have gone on sale as early as February of the preceding year.

For 2014, the Cadillac ELR range-extended electric car will be sold only in the U.S. Exports to Europe and China could begin the following year.

The ELR will launch some significant updates to the Voltec powertrain, though they will be used not only in the 2014 ELR but also in an updated 2014 Volt as well.

Most intriguing is the notion that GM engineers will be able to extend the cars' electric range by expanding the portion of the battery pack the cars can use.

Initially, Chevrolet said the Volt would use only 8 kilowatt-hours of its 16-kWh lithium-ion battery pack.

1.4-liter range extending engine and Voltec drive unit on 2011 Chevrolet Volt

1.4-liter range extending engine and Voltec drive unit on 2011 Chevrolet Volt

By the time the car launched, that number had risen to 10.4 kWh--still leaving one-third of pack in reserve, to provide a buffer for degradation of the cells over the course of the car's life.

If Voltec engineers have grown increasingly confident in the LG Chem cells' lifespan, they might be able to reprogram the control software to permit more of the pack to be accessed for power.

More kilowatt-hours = more electric range.

The question then becomes whether such a software change could be retrofitted into 2011-2013 Volt models.

For that--not to mention any substantial details of the 2014 Cadillac ELR--we'll have to wait.


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