downundarv8builder
Member
I've just commenced test flying on my RV8 down in Australia. I've got an IO375 with the System 32 EFII, a plane power alternator and an ETX680 main battery. The engine is new so the priority is to run it hard and it does get a little warm - CHT's around the 400 degree mark. On the second flight the brand new alternator failed by blowing the field fuse around 20 mins into the flight. Analysis of the G3X data shows that it was producing just 13.2V and just enough current to drive the base load - about 14A when it failed. The same thing happened on the next flight after the fuse was replaced. The alternator was replaced with a serviceable item and 20 mins into the next flight, I got a flashing BATT caution (5 sec flash, off 5 sec), courtesy of the G3X. I landed and investigated and did some homework on the fault light interpretation (possible cell imbalance) and decided to get airborne again to fault find. Before I did that, I charged the battery with the smart charger and it came up clean with no abnormal indications. After about 20 mins, I got the BATT light flashing with normal voltage (14.2V) so I turned the alternator off. After about a minute, I turned the alternator on again with normal indications. After a further 15 mins, the BATT light flashed 5 sec on then off again so I turned the alternator off again for 10 seconds this time and then on again and the system gave normal indications for the rest of the flight. Before anyone criticises my airmanship, this was done over the field and the battery lives in a sealed, ventilated compartment . Has anybody seen anything like this with the ETX680? While I think the alternator issue and the battery issue are separate, they are part of the same system and have happened in a sequence and I wonder if the faulty alternator has somehow affected the battery. The electrical system is lifted straight out of the AeroElectric connection and there's nothing fancy at all going on. The ETX680 cranks the engine like a dream but as soon as the engine fires up, the alternator is using all of its (60A) capacity to charge the battery right away which doesn't seem like it should be good for it. Is there some way to tone that down? Does anybody have any thoughts? Thanks in advance.