Tesla's Supercharger network has long been the most prolific for public EV charging, but roaming agreements are creating a patchwork of other networks that can now compete with Tesla.

The latest agreements, according to aan announcement last week from Greenlots, give EV Connect users seamless access to Shell-owned Greenlots' charging stations, while Greenlots customers are now being welcomed to the stations of FLO, a Canadian charging network.

In March, the FLO announced that its members then had access to 2,250 Level 2 AC and 383 Level 3 DC fast-charging stations stations operated by Greenlots in North America. At the time, FLO said its own app could also roam to access stations from BC Hydro, ChargePoint, eCharge Network, and Electric Circuit.

Roaming has made EV drivers' lives a bit easier, as it allows drivers to access stations from multiple networks with a single app. Previously, drivers needed to maintain accounts—and separate apps, cards, or fobs—for each network.

Monitoring and control system for Greenlots electric-car charging

Monitoring and control system for Greenlots electric-car charging

However, the confusing flow of which network accepts which other networks' members is still a good argument for why the Tesla Supercharger network works so well, despite some disgruntlement. One customer is now suing Tesla, claiming idle fees violate the automaker's promise to early Model S and Model X owners of free Supercharging for life.

Ford relies on a combination of Greenlots and its partners, plus Electrify America, for its FordPass network, offering Mach-E drivers a simplified charging experience.

Electrify America, in turn, has tapped Greenlots for some of its urban charging. In 2017, the Volkswagen-funded network said it had contracted with Greenlots for up to 900 charging stations, primarily for city residents living in apartments and condos, as well as workplace charging.

Greenlots offered some of the first stations that were Plug & Charge-compatible in North America—meaning they don't require an additional card swipe or fob for payment.