Phone not working in a power outage? How to keep it on

Old copper landlines got power from the phone line, so they usually kept working when the electricity went out. The services replacing them, like internet home phone, fiber and cellular home phone boxes, run on your home's power. When the power goes out, they stop, unless you have a backup. That can include medical alerts and alarm panels that now use the internet or a cell box.

Three ways to keep your phone on

Ask your provider for a backup battery

Battery backup for your router and phone box

Federal rules require phone providers whose service runs on your home's power to offer a backup battery: one that lasts at least 8 hours, and one that lasts at least 24 hours. You usually pay for it. Best first step for everyone.

A plug-in battery backup (often called a UPS) keeps your internet and phone box running for a few hours. Best for short outages and a low cost.

Portable power station

A charged cell phone

A large rechargeable battery with regular outlets. It can run your router, phone base, medical alert and a lamp, and charge cell phones, often for a day or more depending on size. Best for longer outages and anyone who relies on medical devices.

The simplest backup of all. Keep a cell phone charged, plus a charged battery pack, so you can always call for help.

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Check your medical alert

How much backup do you need?

1. List what must stay on

2. Check how much power they use

Your phone box or router, cordless phone base, medical alert, and anything else you can't be without.

The power use is on the label, in watts. A router and phone base together often use 10 to 20 watts.

3. Do the simple math

4. Test it twice a year

Battery size in watt-hours divided by the watts you need gives rough hours. A 500 watt-hour station running 20 watts lasts roughly a day.

Unplug the power and make a test call. Batteries wear out, so replace them when they stop holding a charge.

See BLUETTI power stations

Does my provider have to offer a backup battery?

Yes, for most home phone services that run on your home's power. FCC rules require providers to offer backup battery options for at least 8 and 24 hours, and to explain how long your service will work in an outage. Ask them: "Does my service include a backup battery, how long does it last, and how do I check it?"