Attention, Nissan Leaf owners: Your electric car's fast-charge plug is soon to be obsolete.

That's what eight automakers and the Society of Automotive Engineers are certain will happen by the end of July, when the new plug's standards will be approved, the SAE said. Currently, Japan is using the industry's only fast-charge plug standard, called CHAdeMO, which promises an 80 percent charge in just 30 minutes.

It's standard on the Leaf and the upcoming Mitsubishi i, along with various Japanese-market electric vehicles. But in the U.S., automakers, utilities and charging-station manufacturers have been reluctant to use the Japanese plug without an equivalent design from the SAE, which set the plug standard now used on all production electric cars and Level 2 public charging stations.

Audi, BMW, Chrysler, Daimler, Ford, General Motors, Porsche and Volkswagen have all agreed to adopt the new SAE plug standard (shown in black, above) as early as 2013 for U.S., European and other global markets. None has agreed to use the Japanese standard. Another competing fast-charge plug design, developed by a large team of European companies, has not gained traction among automakers since it started in 2010.

The new SAE plug accommodates three different electrical currents into an all-in-one design: 110/120-volt (Level 1), 220/240-volt (Level 2), and the DC fast-charging 480-volt (Level 3). That means tomorrow's electric cars won't need a separate fast-charging port (as the Leaf has, shown at right), which means less confusion and cost for customers, says Mike Tinskey, Ford's associate director of vehicle electrification.

"There's a bit of a VHS-Betamax debate going on," he says. "This [SAE plug] gets us down to a single connector for all modes."

In addition, the SAE design supports Wi-Fi connections, with which a charging station would be able to communicate with future "smart grids" to charge more efficiently and send power back to the utility.

Nissan, however, is not backtracking. In a statement provided to "Exhaust Notes," the automaker said it supports the CHAdeMO standard "across all vehicles and chargers" and estimated that "more than 500" compatible fast-charge stations would be installed in the U.S. this year.

Tesla Motors, as usual, has already fashioned its own plug design for the upcoming Model S. Its two-prong design is much sleeker and thinner than the SAE plug and also can handle up to 480 volts when equipped with Tesla's home unit, the Supercharger. Tesla supplies a fast-charge home unit for the Roadster that can fully charge the car in four hours, versus eight or more on a regular 240-volt connection. When the company introduced the Roadster in 2008, Tesla had to develop its own plug as the SAE hadn't yet approved a Level 2 standard. The company now sells adapters to work with public charging stations.

But fast charging poses bigger risks for battery durability. Proposed Level 3 chargers will be pumping close to 125 amps of power, triple that of a Level 2 unit. As a result, a battery could overheat, shortening its life span and increasing the chance of a fire. However, Ford says the automakers, which offer eight- to 10-year battery warranties, will be installing smarter software to keep a closer eye on the charging process.

"The good news is we know how to measure, and if there are certain conditions in fast charging to avoid, we can do that in the software," Tinskey says.

Battery technology still has a long way to go. New developments from the Massachusetts Institute of Technology show that lithium iron phosphate cells can actually last longer in greater heat. The university also has been experimenting with crystallized coatings that supposedly can allow a lithium-ion battery to charge 100 times faster than current batteries.

[Source: Ford and multiple automakers]