Off-the-shelf EV conversions aren't just for classic cars like Prince Harry's Jaguar anymore.

French startup Transition One plans to make it easy to convert a wide variety of average old cars in the country to electric power by building a standard conversion kit. The company says the kit will fit several top-selling models in Europe, including the Renault Twingo II, Fiat 500, Citroën C1, Peugeot 107, Toyota Aygo, and VW Polo.

The kit will sell for about $9,400 (8,500 Euros), and buyers can receive a 3,500 Euro tax credit in France, bringing the equivalent cost down to about $5,500. The company plans to complete each conversion in about four hours, once production is up and running.

The company has started by building a prototype electric car from a 2009 Renault Twingo, a small hatchback about the size of a Toyota Yaris. It uses Tesla battery modules in three packs under the hood, along with the motor and power electronics, and two more battery packs where the gas tank once sat.

Classic Mini Cooper electric conversion by Swind

Classic Mini Cooper electric conversion by Swind

The packs weigh 265 pounds, giving it about 18 kilowatt-hours of energy, which the company says will deliver about 112 miles of range in the Twingo.

In an interview with Bloomberg, company founder Aymeric Libeau said, "I’m selling to people who can’t afford a brand new 20,000 Euro [$22,200] electric car."

The plan might be compared to that of Montreal's Ecotuned—aiming to convert old Ford F-150s with dying gas powertrains to electric power for fleets. The types of large, body-on-frame trucks that Ecotuned converts are as plentiful in North America as the small cars that Transition One plans to convert are in Europe. Other conversion companies—and some automakers—have begun focused conversion efforts on certain classics, such as the Jaguar E-Type, Porsche 911, and the original Mini Cooper

Libeau still needs to get his conversions approved by European regulators, which he says he expects to receive by the end of the year. Transition One is also seeking financing to buy a factory to produce up to 400 of the conversions a year, and plans to open orders in September to test the market demand.