Duncan Aviation is authorized to modify the Universal Avionics UNS-1C flight management system to include an extended-life battery. A Duncan Aviation tech rep told AIN, “The original battery voltage was 3.6 volts and the new one is 3.93 volts. While the voltage increase in this lithium watch-type battery seems small, it makes a big difference. Previously a battery warning meant a day or two at most until you had a databus failure locking up the entire system. The new battery gives you about three months [after a warning],” he said.