Shawn, thank you for your informative and educational reply with regards to the CR/BR question.
I really appreciate your taking the time to explain it to me.
With regards to the 7.4V backup battery, that price seems awfully high.
I did some searching for other 7.4V 2.2Ah Li-Ion battery packs and they were selling for $30 to $45 and included the protection circuitry.
Is there something special about the ones from Advanced that I'm overlooking?