Electric vehicle owners are being warned to top up if heading over Transmission Gully, because the steep road will drain their batteries faster than the old coastal route.

Laura drove her Nissan Leaf from Waikanae to Wellington earlier this week and said because of the gradient of the road as well as the wind buffeting the vehicle used more power than when she drove the old route around the coast.

“When I drive to Wellington I get there with more than 60 per cent battery at the end, but [over Transmission Gully] I arrived to Wellington with 52-53 [per cent], which is quite a big difference.”

Laura said she previously did the round trip to work and back on a single charge, but she would not risk that now.