why Verizon does not pay for the battery:
1. It is not service impacting, technically you can throw the battery down the street and as long as your PSU is plugged in to steady power then your services will work.
2. If it were up to Verizon they probably never would have installed batteries in the first place, but they are required to in order to give people some kind of back up system in the case of power outage (Googe Fiber was smart not offering traditional voice services)
3. Many people now days use cordless phones in their house anyways, which will not work in a power outage even if you have a battery backup (wireless electricity is just not there yet)
Also to respond to what somebody said, I agree there should be an option to have the battery or not in the first place. In fact I thought I heard that in Texas Verizon is doing a trial program with new customer installations where they will give the customer the option to purchase the battery at that time of install or just not have it at all.