After losing phone service due to a power outage caused by hurricane Irene, I want to add an external backup battery (a PC-type UPS cannot meet my needs). I will use the Aux connector on the FIOS battery backup box (BBU). My plan is to connect this battery only as needed, for roughly two hours a day during a prolonged outage. That should give me about a week of phone service from an 18 AH battery.
Unfortunately, I have found no threads here that reflect hands-on experience with an external battery on the FIOS BBU. My hope is that people with such experience will share it in this thread. Specifically,
Insights on any of the above would be much appreciated, and I plan to post my experience here as well.