It could now cost more to run an electric car than one using fuel owing to the end of UK government subsidies.
The Department for Transport's support for the installation and maintenance of chargers ended in April.
Local councils, left to cover costs, tendered contracts out to private companies - and prices have gone up.
Transport Minister Baroness Kramer told You and Yours £500m was being invested over five years to provide support for electric vehicle drivers.
In the first five months of this year, nearly 2,000 electric cars were sold in the UK - more than double the sales for the same period in 2013.
One of the reasons for the increase is the perception that the running costs of an electric vehicle will be cheaper than a fossil fuel car.
There are concerns that increasing the cost of charging will choke market growth just as it begins to take off.
While electric cars are around £8,000 more expensive than a diesel or petrol one, the government offers a £5,000 grant towards the cost of the car, and will help to install a charge system at home.
Until very recently it was free to charge your car at all public power points. Now Charge Master, one of the biggest providers, asks for £7.50 for a half-hour rapid charge.
Andrew Fenwick-Green, marketing secretary of the Electric Vehicle Drivers Association, drives a Nissan Leaf. He said: "A gallon of diesel for most eco-diesels will cost you £6.30 and get you around 60 miles.
"A 30-minute rapid charge in my Nissan Leaf would give you a range of 64 miles. So we're paying an extra £1.20 more to get the same mileage. It's madness... if the rapid chargers go up to £7.50 we're going to kill the market at a stroke".
The Charge Your Car company asks for £5 for a rapid charge, and Transport for London awarded its contract to the French company Bollore, which will introduce an annual fee of £10 for unlimited charging from September.
Charge Master chief executive David Martell has asked for more support.
"Next year the amount of annual expenditure from Government on infrastructure is going to be slashed by two-thirds, which I think is a little too early.
"We need a few years' more support from the Government to allow proper businesses models to arrive for charging."
Lady Kramer said: "The whole point of this is that you charge at home. That leaves you with a cost of about 2p per mile, which is why it's attractive to the people who have been buying these cars.
"The public rapid chargers are intended for occasional use."
She added that the industry could have communicated with customers better but the shift to charging would not stymie the emerging electric vehicle market.