eufy video doorbell transformer specs for solo installation

My location currently has no doorbell wiring, and I’m looking for an appropriate transformer for the (original, wired) Eufy doorbell. Since there is no current doorbell, a transformer that plugs into a standard 110V outlet is preferable.

In the Q&A section of the amazon listing, there are several answers from Eufy support suggesting a 16-24V 30VA transformer, and a couple suggesting 40VA, and links to a “standard” doorbell transformer like this:

However, there are also many, many reviews claiming successful operation with a wall-outlet-based transformer like this:

The specs on every one of the outlet-based transformers that I’ve seen give the output as 24V 300mA, which would be more like 7VA. (I’m assuming the reason these work is that they’re not connected to the original old-school doorbell, just the Eufy alone?) A plug-in transformer delivering more than 1 amp would be a whole different animal - something like a laptop transformer.

Is there any official word on power requirements for the Eufy living in isolation, without a pre-existing doorbell - specifically, these plug-in transformers? It seems unlikely that the Eufy itself needs 1-2 amps, if people are using 300mA plug-ins.

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Perhaps @AnkerSupport can clarify…the main reason they state a 16-24V 30VA power source is due to it being the standard for US homes (from what I’ve read) which would allow integration or replacement with an existing equipment which is wired…without over complicating installations…

Good day @ndalby to clarify why it needs the 16-24V 30VA power source is because the doorbell and camera use different power draws! Doorbell and audio use 16V most of the time and the video uses 16V-24V depending on the activity and quality of video set. It originally did not make sense to me neither but I spook to an electrician that installs video doorbells and this was his explanation. Also if for any reason you want more than one doorbell you will need a different transformer that will use a straight 24V so they will not be under powered. I hope this helps if Im wrong please correct have a great day/week/weekend :v:

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Thanks, but I’m not asking about the voltage. I’m asking about the amount of power that is drawn (so, volt-amps or watts). There appear to be many people using a plug-in style AC adapter with the Eufy doorbell. In fact, the amazon listing shows that adapter as a “frequently purchased together” item.

What I’d like to know from Eufy is whether there’s any reason to believe such a power source wouldn’t work.

Note that 30VA seems like a lot of power for a camera. Consider: a Wyze wifi camera uses about 4W. And Eufy’s own security cameras charge their batteries at just 10W. The plug-in AC adapters I’m referring to are often used with Ring video doorbells - it seems unlikely Eufy’s doorbell requires 4x that amount of power.

@mitch14 I understand thanks for clarification I miss understood have a great one :v:

Considering our video doorbell needs a transformer delivering 16-24V/ 30VA (or above) of power, we are glad to recommend the following tranformer and adapter for you:



Hope it helps!

Do the transformer and AC adapter need to be used together?

Or is the AC adapter alone sufficient to supply power to the eufy video doorbell?

Based on what anker support posted above with a recommendation of 24v 40va transformers, this translates to an amperage rating of 1.67 amps, which seems to support my findings with the battery doorbell… i currently use a 24v ac adapter with a max output of 800ma (0.8 amps) and the thing does not provide enough power to the doorbell to effectively run — it slowly drains the battery to zero.

Can Anker support confirm they also recommend the same 24v 40va transformer for their battery doorbell as well?

Lastly, looking around for answers on the internet, the ring doorbell 2 (a competing doorbell) state they require a 25ohm 50watt resistor in order to prevent fires if you are looking to use a 24v transformer (or AC adapter) wiring it up like this. Does @AnkerSupport have any comments about this either? Even the transformer listed above has some inefficiencies within the transformer and will actually output 27v instead, so overvolting the doorbell. Whats the max voltage permitted for the doorbell? (30v?)

I wish the documentation about voltage / current requirements were more clear cut.

Anker/Eufy support got back to me, and said that they recommend the 24v 40va transformer here:

But… they didnt answer the question about needing a resistor 25ohm 50watt resistor or not (like Ring highly recommends to avoid fires). In addition, I was told that the wired option charges very “slow”, but clearly the unit doesnt have enough power if it continually drains the battery down to zero.

Really important: Here’s a warning about this specific transformer, or any that provide 24v 40va of output. The amperage will be 1.67amps. In order to avoid fires, you must use at least 20 AWG electric wire (or larger). 20 AWG will support 3 amps. While you can technically go for 22 AWG, which will support 1.8 amps, given these transformers are not regulated, expect some flux and/or spikes in the power delivered. In fact, to play it safe, go with 18 AWG that will support 10 amps if you are running this through your walls, so you only have to do it once.

I will update this thread when new info about the resistor if becomes available. If this saves you some time down the road, leave a note below!

Update: (7/8/2020) - Support got back to me and stated that they recommend a 25ohm 50watt resistor with the 24v 40va transformer for standalone powering of the doorbell. (e.g. if you either do not plan on using pre-existing wiring, or do not have a mechanical doorbell chime).

Resistor recommended by support:

But I suggest using the Ring wirewound resistor as it comes nicely shrinkwrapped and ready to be connected.

It says for use with ring devices only, but its the same resistor type – a resistor is a resistor.

Update: (8/28/2020) - Support has no idea what it is, so i alleged it could possibly be bad hardware.
But given the other posts on other forum posts (and also Mike’s post below) complaining about poor battery management and performance out of their battery doorbell, i doubt it. This just reeks of either a battery management or software/programming issue.

Anyhow, support did send me a RMA for the battery door bell. So I’ll try installing it and returning the old battery doorbell if there’s any improvements. But honestly this feels like Eufy just created a product and decided to screw over their customer base. Whether this was inadvertent, who knows… but it doesnt speak well towards the support of their products.

They seemed to have over promised and under delivered with many of their products.

The biggest gripe with the battery doorbell is the ability to not run this in any fashion but in optimal battery life while maintaining an adequate charge. (here’s the post where i talk about this). If you plan on using any of the advertised features of the doorbell beyond the basic “push to ring” functionality, right now you’ll be rather disappointed.

They also seemed to have under delivered with their homebase 2 stuff as well – with expandable storage, or RTSP support for their doorbells – but thats a different topic.

One additional piece of “anecdata” for you: I noticed that the AC-adapter-style transformer that Anker recommended above provides significantly less than 30VA. It’s 16V @ 800mA = 12.8VA.

Since that model didn’t come with a long enough cord for my installation, I went with this model: which is 24V @ 500mA, and had a couple of positive reviews from people with Eufy doorbells. So far, I’ve had no problems with it.

Also, and don’t quote me on this, I seem to remember some discussion of resistors being specific to an installation where you’re keeping your original bell. In fact, I’m guessing this is significant generally: i.e., the video doorbell itself doesn’t require a whole lot of power, it’s the old-school bell with its ancient electromechanical parts that’s the power hog. If you’re ditching your old bell, you probably have a lot more leeway, power-wise.

I’m not sure that’s a correct answer from Support - that a resistor is required.

The install instructions tell you to install a jumper in any existing mechanical doorbell. This shorts out the mechanical doorbell so it doesn’t ring anymore, but it also removes any resistance it previously presented in the circuit.

This tells me that the eufy doesn’t need a resistor for new installs. You can wire it directly to a transformer.


Hi There,

Can i also connect the Wirelless Doorbell to a doorbell tranfsformator (inside the fusebox). If so, do ineed te same als the wired doorbell? (12/24V 30VA) I’m talking about the EU Version sold bij and

Update (Aug 2020); the doorbell died due to no power even when wired using the new wiring and transformer providing 25.6volts in an optimal battery setting (no motion detection)

This is frustrating to say the least.

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I’m getting the same result.
Did you try adding a resistor and connecting directly to the transformer?

Hi Mike.

I tried both actually. I have an electrical engineer in the family (and i’m in I.T. by trade) so we have a meeting of the minds to figure out what this could possibly be.

The largest problem is the lack of transparency or accessibility we have with the logs in the unit. There’s not enough data for even a techie to figure out what the real issue is here. (whether the doorbell thinks its getting low voltage, amperage, or whatever it might be).

With the proper tools (e.g. commercial multimeter), we tested the voltage from the transformer alone, and saw some crazy output that far exceeds 20% of the advertised 24v. After doing more homework on Ring doorbells which also have a wired component, we figured out that we should ask support if a resistor is recommended so we dont overamp the hardware (and causing a fuse to trip or damage the PCB)

In short, I would not recommend plugging the transformer direct into the doorbell for long term without the resistor, I was getting voltages spiking to close to 30 volts and amperages close to 2 amps as the transformers Eufy is recommending are unregulated. (so… you get some variation / flux in power delivery).

With the resistor, while I was still getting fluxuations, they were much more manageable – between 25.1 - 25.6volts, with around 1.6amps. (or 1600ma) The amps are going to dictate how fast the doorbell is going to charge. It also might help to mention to some of you that are more like minded like me, that i measured this both sides — at the transformer itself, as well as the other end of the 18 AWG wiring terminals running to the doorbell that would hook onto the doorbell. I have about 8m (25ft) of wiring between the transformer and doorbell. We did not see a drop in voltage or amperage from this distance.

Lastly, if you are running this transformer, I strongly recommend using at least 20 gauge wiring — but ideally 18 gauge to support the amperage of these transformers. Solid copper core (not stranded). This way, you don’t cause a fire.

Lastly, check out my updated post above. You’ll see there’s a link to another forum post of mine that contains even more information.

Hope this helps…

Out of curiosity, have you guys been able to determine whether your cameras actually need the number of watts / VA these transformers are capable of putting out? (The original topic of my thread, though I’m not complaining, since I feel like my own setup is working fine.)

My own doorbell (wired version, no legacy bell attached) doesn’t seem to need more than the 12VA I’m feeding it. And as mentioned in a post near the top, my own googling indicated that Eufy’s wireless cameras charge at 10W.

Are you guys who are having power problems all using wireless doorbells and legacy ringers? I doubt that there’s a wall wart that does 25V at 1.5A, but you could try a laptop-style power supply, or a regulated (ugly perforated metal box) style one. At least those would be regulated.

I’m glad to see that the transformer you linked to works fine with the wired doorbell because, I bought the exact same one when I bought the wired doorbell for my daughter, she hasn’t looked it up just yet but it’s good to know for sure that transformer works.

That wired doorBell and transformer would not have worked for my situation ,I installed a 2K battery add on doorbell

In-line resistor or parallel?

Everyone mentions the 25ohm resistor but no clarity on in line (series) to door bell or parallel.

I can see both arrangements achieving purpose, but just want to confirm.

Parallel would ensure the 40va transformer is adequately loaded and would reduce loaded voltage across doorbell…not to mention reduce underloaded transformer losses…

I have the wired eufydoorbell and with a 40va 24v xfrmr. I recorded current draw of 0.15A with wifi and video on. And open voltage on xfrmr of 27v. I presume loaded voltage dropped a bit… as others Mentioned 40va 24v is about 1.67A, so a 0.15A is barely 9%…

Most xformers are very inefficient when underloaded less than 25%… I seem to be getting alot of heat dissipation in the transformer… very warm to touch… but not too hot… I suspect close to 40-50 degrees…

So a 50watt 25ohm resister would perfectly load the 40va if in parallel. But also the series in line arrangement would create about a 3V drop across resistor, leaving just about 24v across the doorbell…

Please confirm what arrangement is reccomended for the resistor ?

I am trying to install a solo eufy doorbell (no traditional bell being used) with a transformer and it is confusing, as at the back of the doorbell it says that:

Input 1: 16-24V ~ 0.3A 50/60 Hz
Input 2: 19v = 0.6A

So I bought a 18v 0.3A transformer that would fit these specification on AC current and would give me 5.4VA. When using this transformer the doorbell lights up, but it fails the power test when configuring the doorbell. It says it needs a transformer with 16V AC with 30VA output, which is way above whats is written on the doorbell. And reading this topic it appears that it can go for a transformer that can output just 12 VA.

I will try to buy a 12VA transformer, although I have seem some reports indicating it can run on 8VA as well.

Not sure if this was already settled, but I recently bought this doorbell. I had it set on a more “aggressive” triggering profile and noticed that my battery had dropped to about 50% in 12 days so I decided I should wire it up. I’m using a custom recording profile in Power Manager --> Customize Recording with 30 seconds record time and it triggers on all motion (not just human) with a custom trigger area. I’ve had it hooked up to the transformer for about 2 days and it has charged back up from 50% to about 75%. I had to wire it to the 24V output on this transformer.

Also, this is the exact doorbell I bought: