MINNEAPOLIS — Faster, more reliable voting machines are arriving in the Minneapolis metro area just in time to help handle a state expansion of absentee voting.

Six of the seven metro-area counties are using federal grants to replace hundreds of 13-year-old optical-scan ballot-counting machines. The new machines are expected to be in place in time for city council primaries in August in Bloomington, St. Louis Park and Minnetonka.

The machines will also be used for the Minneapolis mayoral election in November, which will mark the most high-profile test yet of the city’s system that allows voters to pick a first, second and third choice. The new machines will replace hand counting, which took 15 days in 2009.

The new equipment is also expected to speed up the counting of ballots, including those that are mailed in and those that are cast on Election Day.

Virginia Gelms, the acting manager of the Hennepin County election division, said the machines are designed to prevent paper jams.

“Ultimately, that leads to results available earlier on election night,” she said.

Hennepin County was the first to buy the new machines, spending $4.1 million for 550 precinct counters and four central counters. Anoka County, which spent $1.5 million for 140 precinct ballot counters and one central counter, plans to use them in the Anoka-Hennepin School District election this fall, said elections manager Cindy Reichert.

Ramsey, Washington, Dakota and Scott counties are in the process of making purchases. Carver is the only metro-area county with no plans to buy new machines.

The new machines will read and count paper ballots like the old ones do. But a 12-inch display screen will alert voters if a ballot error is made and provide instructions to correct it.

Unlike the old optical-scan machines, which simply scanned the ballot to count the marks, the new digital-scan technology makes a digital image of the ballot and looks for darkened pixels in area where votes are marked, Gelms said.

“If enough darkened pixels are detected, the machine registers the vote,” she said.

Ramsey County elections manager Joe Mansky said the old machines were reliable and accurate, but ballots had to be hand-fed one at a time. The new ones should allow for faster processing, he said.

Elections officials are especially concerned about absentee ballots because of the new “no excuse” law. In previous years, voters had to have a recognized excuse such as an illness or out-of-town trip to request an absentee ballot. Under the new law, anybody can vote absentee for any reason.

As an election nears, Ramsey County can get 1,000 or more ballots per day, Mansky said.

“We want to be sure our new voting system will accommodate a large number of ballots coming by mail,” he said.