We have received a Release to Service from the Tecnam agents. Summary from the LAME below:
Information supplied by Tecnam Australasia. I spoke to the assembly line technicians and engineers with electro-avionics on the issue of overload voltage, referring to them the type of battery (ALIANT ultralight lithium iron battery) mounted on the Sierra in question. I replied that, in fact there is no problem for the airworthiness of the aircraft because with this type of battery, the voltage of 14.9 volts is normal for its operation(in this respect, it is considered overchanging only when the battery voltage exceeds 15 volts) It is the same case for the Astore. Therefore,the fact that the voltmeter reads that value is normal, as per design of the electrical system. The high value of voltage detected is due to the presence of a resistance in series on the point C of the regulator. This resistance has been inserted to allow the battery to fully charge during the flight and then allow the client to be able to restart the engine while the aircraft has not been operating for a long time. Nothing prevents, however, to take away the resistance bypassing it. Obviously this will lengthen the charging time of the battery. In a nutshell (considering for example a flight that lasts 1h) - With the resistance - battery charges faster - Without resistance battery will charge less, with the possibility that the battery can not ensure the necessary current for future engine ignition.