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AIRFRAME TECHNOLOGY load, the following procedure is recommended: Measure the parasitic load as described previously. Determine how long it will take to deplete 10 percent of the battery capacity using the following formula: Time (hours) = 0.10 x C1 x 1/Ip, where C1 is the battery's rated capacity in Ah, and Ip is the parasitic drain in amperes. For example, if C1 = 28 Ah and Ip = 0.05 amperes (50 milliamperes), then Time (hours) = 0.10 x 28/.05 = 56 hours = 2.3 days. If the aircraft is inactive for more than the time calculated in step Introducing the Concorde RG-390E battery installed in Sikorsky S-76B helicopter. (2), either: Disconnect the battery plug (preferred) or connect a maintenance charger to the battery. It should be noted that repetitive cycling of the battery by a parasitic load may shorten the battery service life. Therefore, the sooner the battery plug is disconnected or a maintenance charger is connected, the less impact it will have on the battery life. Also, if a maintenance charger is used, make sure the charger puts out the correct "float" voltage. Excessive float voltage may shorten the battery life even more than the parasitic load. For Concorde RG Series batteries, the correct float voltage is 13.3 volts for 12-volt batteries and 26.6 volts for 24-volt batteries. Lessons learned Over the past few years, Concorde engineers have had the opportunity to measure the para- sitic load on a wide range of air- craft. Measured values have ranged from under 1 milliamp to as high as 1.29 amps (1,290 milliamps). For the majority of aircraft, the measured values have fallen between 1 and 100 milliamps. One particular aircraft will be used as a case study, although the make and model will not be The most complete way to pinpoint leaks in virtually any aircraft fluid system! Works in fuel systems and with petroleum- and synthetic-based hydraulic fluids! Reduces aircraft downtime. Helps prevent major equipment failure. Kit Includes: • Rechargeable, super-high intensity UV leak detection flashlight • Universal fluorescent dye • Dye cleaner • AC and DC chargers • UV-absorbing glasses, holster and soft carrying case or visit www.spectroline.com 22 September 2011 Aircraft Maintenance Technology • www.AMTonline.com • www.AMTSociety.org For more information, call 1-800-274-8888