Praise and thanks to the local Batteries Plus store. The “replace battery” light and buzzer came on for the battery backup that keeps the phone working with Verizon FiOS for a few hours during a power failure. This was the second battery. I replaced the original battery just a year ago, after four years.
I took both of the allegedly failed batteries to the Batteries Plus store, and the guy there, working by himself on a Sunday, said “Verizon FiOS? I bet they both test fine.” And, indeed, they did. His explanation was that the FiOS UPS seems to have a habit of overcharging batteries then declaring them worn out, prematurely.
He suggested discharging the battery with a light or letting it sit for a week or two. Well, the original battery has been sitting idle for over a year, so I figured I’d put that back in and, if the tech at the store was right, it would work. And it did. So now the question is, how long will it last? Maybe I should let it run down for an hour or two once in a while. The only catch with that idea is, unplugging the power supply will leave the phone working off the battery, but Internet and TV service will be down.
Follow-up: Six days later the original battery is still OK.
I found nothing at all about this on the various forums (DSL Reports, etc.) or on Verizon’s pages, but the guy at the store looked at the batteries and correctly guessed FiOS. I’m hoping this theory holds up and I’ll be able to keep the two batteries going for a significant time.
Hmm… Haven’t experienced this myself yet (or haven’t noticed — I should go check my light!). But your post made me do a search for
fios ups overcharge battery
and your site was the first hit. It’s either not a common problem, or not a well-publicized one.