Can't do backup battery check because it never reaches 12.25 volts.

[donramm]

I did backup battery test once. Next time the message said I had to do the backup battery test, I tried but it hadn't reached 12.25 volts so could not initiate the test. Dynon SkyView Touch is 10 years old so I figured battery is bad. Bought a new backup battery from Dynon...and I still can't do a backup battery test.

When I'm cruising (RV-12 with ROTAX 912ULS at 5000 RPM) the "BATT VOLTS" is 13.8-14.0. I flew for 2.3 hours yesterday. Checked backup battery volts after the flight and it was 12.05 volts.

What I haven't done is an inflight check of the page that shows backup battery, the voltage being applied, and the state of the backup battery: Charging, Discharging, or Charged. I wonder if, for some reason, the changes to "Charged" before it reached 12.25 volts so I'm never getting above that and can't do a backup battery test.

Anyone out there have this problem with SkyView in an RV-12?

 

[wilkersk]

I believe 12.25vdc is about 60% state of charge for that battery. That's probably the minimum voltage that the Skyview would allow you to initiate a battery test, which makes sense.

Try an open circuit reading of the battery voltage (read across the open leads of the disconnected battery with a voltmeter). Then compare that reading to what your "local display" setup page is showing for backup battery voltage. I suspect it will end up being that you have a bad battery from Dynon (probably not), a faulty display, or there could be a problem with your wiring causing an errant a voltage drop.