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,
How are you charging the battery? From an external charger or from the BBU charger?
If using an external charger, do you connect to the battery to BBU Aux only when AC power is unavailable? My guess is that would be required to avoid problems with or damage to the BBU by the external charger when the internal charger is also active.
After pressing the blue emergency button to enable the external battery, what happens if you later disconnect it? Does the internal battery remain in "emergency" mode?
Does pressing the blue emergency button a second time switch the internal battery out of "emergency" mode? That would be very useful.
Have you had any unforeseen problems installing or running FIOS phone from your external battery?
Insights on any of the above would be much appreciated, and I plan to post my experience here as well.