Backup Battery 320

[1984]

Today shortly after takeoff my aircraft battery failed to power my Skyview. The Skyview700  responded with the proper warnings: operating on backup battery, and battery voltage low. The planned flight was very short anyway, so I continued for another 10 minutes on backup battery power. On the ground backup battery voltage showed 11.18 and >45 minutes of power remaining. I "rebooted" everything and the Skyview displayed that the backup battery was being charged. I ran a successful backup battery test at my annual inspection in September. Question 1.: What is the threshold for "backup battery voltage low" message? 11.18v seems too high to trigger that warning. Question 2.: When the backup battery can no longer power Skyview, at what voltage would that occur?

 

[dynonsupport]

11.18V is not telling you you have 45 minutes left- it's telling you the last time it was tested a fully charged battery lasted more than 45 minutes, but not that you currently do. With Lithium Ion you don't have an accurate way to tell how much time is left. If we did, we'd just report that in the warning bar.

A backup battery is fully charged at 12.25V. SkyView will turn off at 9V, but it will fall from 10V to 9V in about 60 seconds, and from 11 to 10V in just a few minutes. 11.18V is pretty low, which is why you were getting the warning.