Ecotricity, the provider of the majority of electric car chargers at motorway services, will begin charging £6 for a 30min fast charge from today.
Last week, the company initially said it would be charging £5 for 20min, but owner Dale Vince announced the new cost on Radio 4 today.
A spokesman for Ecotricity said: "We looked at the response to the announcement last week and decided it made sense to offer a different price, based on the feedback we received."
The company has started upgrading the hardware of its entire charging network to accept payments from a new app, and it expects all of its chargers to accept payments by Friday 5 August.
Users must download the new Electric Highway app, which allows drivers to pay at the pump. The app also shows a live network of Ecotricity chargers to see the location and availability, and enables drivers to track the progress of their charge.
The company has 296 charging points across the country, with 99% of them at motorway service stations, but it expects to double the number of chargers in two years and introduce some to cities. A fast charge point could give an electric car an 80% charge after 20-30 minutes. There are around 20 slow chargers in Ecotricity's network, which could charge an electric car up to 80% in around one hour, and these will remain free.
Ecotricity says the usage of its charging points trebled in 2015, and in its statement announcing the original £5 fee said: "It is now necessary to start charging for the service in order to maintain and grow the network."
The move to charge for electricity could mean charging plug-in hybrid models, like the best-selling Mitsubishi Outlander PHEV, at motorway services will become financially uneconomical because of their limited electric-only ranges.