Electric Rental Cars Orlando (This Sept. 4, 2013 photo shows Orlando Mayor Buddy Dyer connecting a charging cable to  a new elec

It's the hurdle that electric vehicles must clear to be launched into the mainstream: range anxiety. But this time it isn't prospective customers who worry about running out of juice, Bloomberg reports, but renters who return to car rental agencies before their lease is up and trade their EVs in for more traditional gasoline-powered autos and gas-electric hybrids.

"People are very keen to try [electric vehicles], but they will switch out of the contract part way through ... they think they can't get to a charging station," says Lee Broughton, head of sustainability at Enterprise. Enterprise customers who rent EVs reportedly trade them in 1.6 days into the rental period on average, which compares unfavorably to the six- to seven-day rental periods of traditional, fuel-burning automobiles.

Christopher Agnew, an analyst at MKM Holdings LLC, says that longer range would help rental customers' range anxiety, especially since they are usually renting vehicles in unfamiliar places.

And if consumers want an EV with a range that exceeds 100 miles, they'll have to step up to a Tesla Model S, which can achieve a maximum of 300 miles but is in a much higher price category than vehicles such as the Nissan Leaf due to its exotic-luxury-car status. MPG Car Rental in Venice, CA, near the Los Angeles International Airport, rents Leafs for $99 per day, while Model Ss go for $500 per day.

Despite these developments Enterprise, Hertz and MPG Car Rental all say they will continue to buy EVs for their fleets.