The battery in my Fios box is beeping and I also received an e-mail from Verizon that they have detected my failing battery. Verizon warns that it is best to buy a replacement from them because other brands may cause problems or even damage to your system. Question 1: is there any truth to this - is it a risk to buy a battery from someone other than Verizon? Also, I see replacement batteries on Amazon for $17 or $18, whereas Verizon wants $35 and Radio Shack wants $39 !! Question 2: Has anyone ever purchased one of these cheaper batteries? Are they dependable and as long-lasting? Thanks.