Greg Arehart
Well Known Member
So, today I was flying north and about an hour out of Reno I noticed on my Dynon D120 that my battery voltage fell below 12.5, and was discharging 5-6 amps. I monitored it for a few minutes, and nothing changed. My immediate thought was alternator failure, or a blown fuse. Not wanting to end up with a problem away from home, I aborted the trip and turned around and flew back to Reno. Enroute the voltage continued to drop and the amperage continued to show discharging (though I did shed some electrical load by turning off some non-essential stuff).
Back on the ground, I pulled the cowl and put my voltmeter on the battery (Odyssey). Lo and behold, it showed about 13.8 volts! Seems not very discharged to me, considering that I flew at least an hour with the Dynon indicating discharge on the ammeter and low voltage (I was down to 11.2 by the time I landed). More checking with the meter and the voltage at the buss is 13.7, on the wire to the D120, while at the very same time the D120 is giving me 12.2 volts as a reading. I've spoken to Dynon and they are scratching their collective heads and maybe will have some insights to share with me tomorrow. Or maybe I'll be sending the box in for inspection.
A couple other bits of info. I did not try to restart (it was in the hangar before I pulled the cowl and getting cold outside so I didn't want to pull it back outside). On the return portion of the flight, the ammeter was pretty much steady (discharging) but the voltage seemed to fluctuate up and down by several tenths of a volt with no change (that I'm aware of) in the electrical draw.
If anyone else out there has any thoughts as to what might be going on here (or seen a similar problem with the D120), my ears are open.
Thanks,
Greg
Back on the ground, I pulled the cowl and put my voltmeter on the battery (Odyssey). Lo and behold, it showed about 13.8 volts! Seems not very discharged to me, considering that I flew at least an hour with the Dynon indicating discharge on the ammeter and low voltage (I was down to 11.2 by the time I landed). More checking with the meter and the voltage at the buss is 13.7, on the wire to the D120, while at the very same time the D120 is giving me 12.2 volts as a reading. I've spoken to Dynon and they are scratching their collective heads and maybe will have some insights to share with me tomorrow. Or maybe I'll be sending the box in for inspection.
A couple other bits of info. I did not try to restart (it was in the hangar before I pulled the cowl and getting cold outside so I didn't want to pull it back outside). On the return portion of the flight, the ammeter was pretty much steady (discharging) but the voltage seemed to fluctuate up and down by several tenths of a volt with no change (that I'm aware of) in the electrical draw.
If anyone else out there has any thoughts as to what might be going on here (or seen a similar problem with the D120), my ears are open.
Thanks,
Greg