At least four competing Formula E entities are considering tendering for the supply of the championship's control battery from season five.
Mahindra, DS and Renault have confirmed to Autosport they are evaluating a proposal while current battery supplier Williams Advanced Engineering, which is partnering Jaguar for the British manufacturer's racing return next season, has also hinted it will tender.
The postponement of open battery competition is to be extended until season seven at the earliest, but manufacturers in the series are keen to win the right to supply the entire grid to gain valuable experience.
Indian company Mahindra will soon sell its first electric vehicle in the UK, the e2o, and is using Formula E to enhance its road-car division after purchasing Indian car company REVA in 2010.
Team boss Dilbagh Gill told Autosport: "Batteries are a priority for Mahindra. We're going to continue developing that, and we were ready [to provide our own battery] for season three.
"We will look and evaluate the tender. It's a sensible roadmap, it's achievable - what we need for season five we have in our laboratory."
It's understood that the next rule cycle - the core elements of which should be a battery weight of 330kg, 250kg of cells, 54kWh of useable energy and a peak power output of 250kW - will again last four years, with the control supplier set to be handed a two- or three-year deal.
That means a control battery for seasons five and six and competition being introduced for season seven, so teams that choose not to invest in battery development can retain the spec product and not be at a significant disadvantage.
Sylvain Filippi, chief technical officer at DS Virgin Racing for season two, confirmed the French company was taking the tender seriously because it intends to manufacture its own battery when the regulations allow.
"It's crucial to know how to make batteries, we want to develop everything," he said.
"Some really interesting solutions will come up.
"You could put a rule in saying no current competing manufacturer can apply but that's stupid because you're limiting half the companies that can bid."
WAE technical director Paul McNamara revealed it launched an internal study last year to evaluate how one battery can complete a full race distance, as is the championship's target for season five.
The company's new partnership with Jaguar caused controversy in the paddock because of its knowledge of the batteries through its existing supply deal.
Renault's Formula E project leader Vincent Gaillardot said the experience that can be gained from that sort of arrangement meant a supply deal was appealing to the French manufacturer.
"We have put on the table all the possible scenarios," he said. "We have to keep developing technology, to reassure us we're ready for the future."