A fleet of seven electric buses will arrive in downtown Dallas by the end of March.

The quiet, battery-powered buses will be painted pink for DART's free downtown D-Link service and roll out on March 25.

A prototype of the bus arrived last week in Dallas for testing.

“We're testing it, suggesting changes, and the contractor's with us as we're doing all that. Ultimately we'll agree to it, change the color and put it in service,” DART spokesman Mark Ball said.

DART was able to purchase the buses through a $7.6 million grant in 2015 from the Federal Transit Administration.

Initially, the buses were expected in 2016. Ball said he wasn’t sure what caused the delay.

“Typically, it's politics, but exactly what happened, I couldn't tell you,” he said. “It's just one of those things where we're just happy it all came about.”

Each bus will cost about $971,000, and chargers for the buses will total about $810,000. To charge, the buses will pull into the station at the Dallas Convention Center, where batteries on the tops and bottoms of the buses will be recharged, Ball said.

Charging will take about 10 minutes, and a charge will last for 30 miles.

D-Link riders will notice a few differences in the buses the Proterra company is specially making for the city.

A prototype of the electric buses coming to Dallas for DART's D-Link (Mark Ball / DART)

They’ll be much quieter, Proterra founder Dale Hill said. From the outside, the buses’ noise will be about 68 decibels — about the same sound level as people talking in a meeting room.

Passengers also will notice the buses emit no odor because they don't have engines.

DART is getting Proterra’s first 35-foot buses — smaller than DART’s typical 40-foot buses to help them navigate downtown city streets more easily. They’ll seat 27 and have standing room for 30 more people, Hill said.

If the electric buses are a success, Ball said, DART will consider expanding electric transportation options.

“It just so happened that we did have the D-Link available to us, which seemed to fit the requirements to this type of bus operation perfectly," he said. “The fact that it is a green opportunity makes us happy as well.”

Over the 12-year lifetime of one of the electric buses, DART can expect to save $300,000 to $400,000 on fuel.

“We used to say that we were doing battery-powered electric buses for the sake of sustainability. I tell people today that we're not here to talk about sustainability — we're giving you that for free,” Hill said. “We're here to talk about saving money.”

CORRECTION, 9 a.m., Jan. 19, 2018: An earlier version of this article referred to Dale Hill as Proterra's CEO, not its founder.