So far, the Tesla Model S is alone among plug-in electric cars in providing 200 miles or more of electric range.

But as Tesla Motors [NSDQ:TSLA] prepares to roll out its more affordable Model E late in 2016, it may face serious competition from General Motors.

GM is developing a Tesla-rivaling car that can go 200 miles on a charge and would cost $30,000, The Wall Street Journal reports.

(Tesla CEO Elon Musk later tweeted, "Am happy to hear that GM plans to develop an affordable 200 mile range electric car. Right target. Hope others do same.")

But while the General has the technology to build this new electric car, it won't go on sale particularly soon--due to high battery costs, said Douglas Parks, GM's vice president of global product programs.

He made the comments at a ceremony opening an expansion of GM's battery test lab at the company's Technical Center in Warren, Michigan.

Tesla is widely thought to have the lowest battery cost per kilowatt-hour of any plug-in electric carmaker.

It uses thousands of Panasonic "commodity" cells, specially designed to be even less expensive than the ones used in your laptop, and has many patents on this unique approach--which is not presently used by any other automaker.

This isn't the first time GM has discussed an electric car with a 200-mile range range that would sell for the price of a nicely-equipped mid-size Malibu.

Back in March, GM CEO Dan Akerson confirmed that his company was working on such a car, citing breakthroughs in battery technology "on the horizon" that would make it possible.

One such breakthrough may come from Envia Systems, a Newark, California-based company in which GM invested $17 million in 2011.

Envia specializes in lithium-ion cathode technology, and claims it can create batteries with greater energy density.

Specifically, Envia has claimed an energy density of 400 watt-hours per kilogram--much higher than the 140 watt-hours per kilogram of the Nissan Leaf's battery pack.

GM may be waiting for this battery technology to become available for its Tesla rival, rather than using the same LG Chem cells as the Chevrolet Volt and Cadillac ELR.

Currently, GM's only battery-electric car is the Chevrolet Spark EV, which has a maximum range of 82 miles and starts at $26,685.


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