It's been 10 years since New Hampshire started its E-ZPass electronic tolling system, and some of the oldest transponders are nearing the end of their battery life.
Customers with transponders that are at least nine years old are being asked to check their account statements. If their license plate numbers are listed instead of their transponder numbers, the transponder isn't working.
Those with non-functioning transponders can replace them for $8.90. Starting Sept. 1, any tolls recorded based on license plate images will reflect the full toll rate, instead of the 30 percent discount for passenger vehicles and 10 percent discount for commercial vehicles.
The Department of Transportation says nearly 80 percent of the first 300,000 transponders sold were used at least once last year.