said by Tomek:
My local cellphone tower is behaving erratically, my phone jumps from 4G to no-G and anything in between. I have to drive half mile north for good signal.
Since I am FIOS customer by battery backup was done after 8 hours. I don't have generator and i will be stuck for days without power. I was able to connect car battery via inverter and FIOS works fine. Internet and phone (not enough juice for TV).
Just be sure you have the battery in a well ventilated the space to avoid hydrogen buildup.