Two pathways are emerging as electric vehicle charging infrastructure expands across the US Automaker partnerships will determine whether those technologies will coexist or whether one will push the other out, like VHS and Betamax.

Four months ago, the US was heading toward a standard way of charging EV with chargers other than those built by Tesla using a common connector to become eligible for federal funding. Tesla’s charging agreement with Ford Motor Co. and General Motors threw that push to standardization into question and could further fragment the country’s charging infrastructure, at least for now, analysts say.

GM and Ford reached agreements with Tesla that will allow the automakers’ EVs to charge at 12,000 Tesla Superchargers starting next spring. Ford announced its agreement May 25, and GM followed two weeks later.

Before Ford’s announcement, the Combined Charging Standard was becoming almost universal charging technology for non-Tesla chargers. EV chargers built with funds from the $5 billion National Electric Vehicle Infrastructure formula program must have a CCS connector.

“We thought CCS won in the US because of NEVI,” said Loren McDonald, CEO of consultancy EVAdoption. “Now some people say [Tesla’s standard] has won. I’m not sure that’s true. We might have this split.”

The demise of CCS could be imminent if other automakers followed Ford and GM by adding Tesla charging sockets, called the North American Charging Standard, to their vehicles, analysts said.

CCS ports run one connection between the charger and the EV, said Conrad Layson, senior alternative propulsion analyst at AutoForecast Solutions. Tesla’s NACS port exchanges more information and usually leads to a smoother charging experience, he said.

Charging networks and charger manufacturers are racing to update their systems with Tesla’s NACS connector. Under NEVI standards, each charging port must have a CCS connector. However, ports are allowed to have other nonproprietary connectors, such as Tesla’s NACS, if the port is also capable of charging a CCS-compliant vehicle.

“The goal of NEVI was to move the industry toward CCS,” said Amaiya Khardenavis, EV charging infrastructure analyst at Wood Mackenzie, an energy research and consultancy business. “Now since NACS is the most adopted, which way are we going to go and does the NEVI rule change?”

Charging companies aren’t waiting to find out. Many said they are adding NACS connectors to their chargers.

EVgo already has about 600 chargers integrated with the Tesla connectors and will continue to “deliver the reliable and convenient charging experiences needed for all EVs,” the company said in a statement.

Several charging companies, such as ChargePoint, Flo, FreeWire and ABB E-Mobility, said they would support technology that makes charging more convenient.

Volkswagen Group’s Electrify America, one of the largest charging networks, said it would listen to customers and continue to evaluate the market.