Internal battery, voltage and lifetime

[Werner_Schneider]

Came back yesterday night and shutdown the engine then shutdown the master switch and my D10A came on the right hand info up with voltage (normal VSI) as it was on the intrenal battery, nice feature which I was not aware off BTW :

Now I was 45 minutes in the air with engine running, I have disconnected the keep alive and the voltage of the internal Battery showed 15.9V. I expected to see 16.8V right after shutdown of the Master so I'm just wondering, I've the EFIS since about 4 years (however made the D10 to D10A upgrade. Seeing that voltage do I need to be concerned that the internal battery might have lost some capacity, is there already a recommendation to replace the internal battery after some time in order to keep the 1.5h backup time?

Thanks a lot for a feedback

Werner (thinkig about an RMA to get also the engraving on the D10A )

 

[dynonsupport]

The best test of your battery is really to do the rundown test as specified in the manual. That said, it might just be that your battery isn't quite topped off. Also, 15.9 volts is almost, but not quite full.