Why does the DoorVi sign need no battery?

Because there is no camera, microphone, speaker or radio inside it. The sign carries a printed QR code and a passive NFC tag, and a passive tag draws the tiny amount of energy it needs from the phone reading it.

How often do battery doorbells need charging?

It depends heavily on how much activity passes the door, how many recordings are triggered and the weather, since cold reduces battery performance. Manufacturers publish estimates, but real-world intervals vary a great deal.

Is a wired doorbell better than a battery one?

A wired doorbell removes the charging routine and is generally more consistent, but it requires suitable wiring and often an electrician, which is not always possible in rented or leasehold property.

Does a battery-free doorbell still work in a power cut?

The DoorVi sign is unaffected by a power cut because it uses no power. The call itself still depends on the two phones having charge and an internet connection, so a broadband outage would mean relying on mobile data.

Guide

Can You Have a Video Doorbell Without Batteries?

Three different approaches, three different power stories. Here is what each one actually asks of you, and why one of them asks for nothing at all.

Published by DoorVi Ltd · Last updated 7 August 2026

In short

Yes. A wired doorbell avoids batteries by using mains power, and a visitor-initiated doorbell such as DoorVi avoids power at the door entirely — the sign has no electronics to run, because the visitor's own phone supplies the camera, microphone and connection.

Three approaches, briefly

Battery-powered camera doorbells

A self-contained unit with a camera, microphone, speaker and Wi-Fi radio, running from a rechargeable pack. Easy to place anywhere, but every one of those components draws power, so the battery has to come off the wall and go on charge periodically. Busy doorsteps and cold weather shorten the interval.

Wired camera doorbells

The same hardware, powered from existing doorbell wiring or a transformer. No charging routine and generally more consistent behaviour, but it needs suitable wiring in the right place, usually an electrician, and often permission you may not have in a rented or leasehold home.

Visitor-initiated QR and NFC calling

A sign rather than a device. It carries a printed QR code and a passive NFC tag. When a visitor scans or taps it, their phone opens a secure video call to the occupant. Nothing in the sign consumes power, so there is nothing to charge, replace or fail.

Why the DoorVi sign needs no battery

The question is easier to answer once you look at what is missing from the sign. There is no image sensor, no microphone, no speaker, no Wi-Fi or Bluetooth radio and no processor. Those are the parts that consume energy in a camera doorbell.

What remains is a printed code and a passive NFC tag. The tag is a small antenna and chip with no power source of its own; it harvests the minute amount of energy it needs from the field of the phone held against it, for the fraction of a second it takes to transmit a web address. That is the same principle as a contactless travel card.

Nothing to recharge, ever.
Nothing to replace as batteries age.
No performance drop in cold weather.
No device off the wall while it charges.
No firmware updates and no battery health to monitor.

Comparing the power story

How power requirements differ across the three approaches. Specifications vary by product — check current details with the manufacturer.
	Battery camera doorbell	Wired camera doorbell	DoorVi QR / NFC sign
Power at the door	Rechargeable battery	Mains or transformer	None
Routine maintenance	Periodic recharging	Occasional; wiring dependent	None
Affected by cold	Yes, battery life reduces	No	No
Works during a power cut	Until the battery runs down	No, unless backed up	The sign is unaffected
Needs an electrician	No	Often	No
Records footage	Yes	Yes	No

What a battery-free doorbell does not do

Being honest about the trade-off matters. Because there is no camera in the sign, a visitor-initiated doorbell cannot record footage and cannot alert you to motion. It answers the question "who is at my door right now and what do they want?" — not "who walked past at three in the morning?".

If recorded evidence is your priority, a camera doorbell is the right tool. If reliability with zero maintenance is your priority, a battery-free sign is hard to beat.

What still needs power

To be precise: the sign needs nothing, but the call still involves two smartphones. The visitor's phone needs charge and an internet connection, and so does yours. Nobody should tell you otherwise — a video call is a video call.

Frequently asked questions

Yes, in two ways. A wired doorbell draws mains power instead of using a battery. A visitor-initiated doorbell such as DoorVi needs no power at the door at all, because the visitor's own smartphone provides the camera, the microphone and the connection.

Continue reading

Nothing to charge, ever

Fit the sign once and forget about it. See how the call works in the live demo.

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