Electric-car charging stations are being added to more and more public parking lots, curbsides, corporate garages, and a host of other locations.

But as any electric-car driver can tell you, many of them are operated by specific networks. They often require drivers to have set up an account beforehand, and to validate their charging session with a special membership card.

In practice, that means drivers must set up multiple accounts with multiple charging-station networks--and carry up to seven cards, fobs, or other authentication devices to be able to use the majority of charge stations on their travels.

Now, two large networks of charging stations have formed a company to enable and promote interoperability--not only among their stations, but others as well.

In effect, that means that electric-car drivers will be able to join one network but "roam" among other networks of charging stations, just as mobile-phone users can move seamlessly among networks without having to know which company operates the one they're connecting through.

The new venture is called Collaboratev, and it's been founded by ChargePoint and Ecotality, which operates the Blink network.

Its goal is to enable a "seamless process" for electric-car drivers to charge across multiple networks.

Collaboratev hopes to establish common authentication credentials across the different networks now operating, and provide users with a single bill regardless of which network they charge on.

It will also aggregate data on charging behavior--very important for understanding how drivers use and recharge plug-in electric cars in the real world--across all participating networks.

A payment system across multiple vendors, said Pike Research analyst John Gartner, would "alleviate consumer concern [over] being tied to one charging netowrk, and therefore make electric vehicles more attractive to mainstream vehicle buyers."

The announcement came this morning from ChargePoint and Ecotality; more information will be available on the Collaboratev website.

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