D10A EFIS Backup Battery issue

[Bud_Keil]

My D10A EFIS will not operate on the backup battery. The internal D10A battery voltage is 15.6V while the Master Switch voltage is 13.2V. The D10A Engine Voltage is reading 0. My D10 EMS, however, is showing the alternator is charging 13.3V at 13amps. So, somehow, the EFIS is not sensing the engine voltage. I never received and EFIS low voltage alert. Any ideas on where I need to start looking to resolve this issue?

 

[Dynon]

That second line, E, is for external backup power, if you had a redundant electrical system. Almost no-one does, so 0 is normal there. 15.6V for the internal backup battery is pretty low for the pack, and represents a pretty discharged battery. Full is 16.2 volts, for reference. You may need to just fly for a while to recharge the battery, but if it never really increases (16v is a good threshold), you may need a new backup battery.

 

[Bud_Keil]

Thanks for the quick reply. I will check to see if the battery pack charges on a longer flight. If not, I'll replace it. I guess 15yrs out of a battery pack is a decent life expectancy.

 

[Bud_Keil]

Replaced the back up battery and solved my problem. It wouldn't charge on a longer flight. The battery pack that I removed was not a Dynon brand and apparently had been replaced previously without an entry in the logbooks.