Becker AR4201 Low Voltage Warning

According to the Becker manual, the 4201 Low Voltage warning (blinking of the display) kicks in when the supply voltage drops to 10.5. I'm wondering if anyone has had a reason to independently check this out for accuracy. Reason for the question is that my Becker seems to be indicating low voltage before it "should".

I run two 12V 12AH SLA batteries (independent circuits) which I just load tested (thanks to the John DeRosa article in soaring). The newer battery shows almost new performance (6.5 hours to terminal voltage under a 1.7A load). The older one shows nearly 70%.

The average load in my glider is about 1.8A (Radio, Xponder, Clearnav and vario assuming 5% transmit and fairly frequent interrogation on the Xponder).. The radio frequently starts blinking after only a couple of hours. Nobody has complained about the transmit quality. And yeah, I know the Becker has a built in volt meter. I just never thought to turn it to that page when this happens.

Any thoughts?

P3