I just installed my Eufy Wireless battery doorbell on Tuesday. I have an exisiting mechanical chime and wires so have used that instead of the battery. The app shows the green plug icon. So for me, I assumed that the bell was working off the power on the transfomer. Today (Friday), less than 3 days later, my son was left standing outside when he returned from school. I only heard when he knocked on the window. When I checked the Eufy App, i was shocked to see that the bell had turned off because it had no battery charge left. I mean WTF??? Does this sound like a faulty doorbell or have i done something wrong?? Can someone enlighten me please? As I said, the app shows the green plug icon, not battery status, so really not sure whats wrong
The transformer you are using is only 1/3 of Eufy specs. They recommend a 18-24 vac at 30VA. Your transformer only rates 9 VA. The doorbell itself takes more than 500ma to keep it working, so its not a surprise that it isn’t getting charged.
I used the following transformer. And works fine.
Your transformer may work with the wired doorbell, but its right on the edge. It doesn’t have the current capacity to use with the battery wireless doorbell, especially if you use it with the mechanical chime. Eufy recommends 30 VA for that reason.
I have purchase the transformer mentioned above British General 8-24V 8VA Bell Transformer and its not charging. What percentage does the battery need to be before charging starts ?
I am trying to drain it at the moment its at 87% ?
Ah mine is a battery one maybe I need a 30VA one like this one or at apush try a 15VA like this ?
I have the battery one too, and used the below as guide. I took the power from a plug and used 1 and 4 connection from the transformer. Mine drops down to about 82% then charges upto 90% so far all seems to be working.
Ah mine is just getting down to 82% so may work. I will get back.
Can I asked another question when it drops to 82% and starts charging do you get the little plug sign or annimated the % charge sign ?
If I plug it in to the homebase via usb then I get the % charge animated sign. With the transformer plugged in it just shows the plug sign only when its switched on.
I have it connected to 24v 1 and 4 terminals and a plug connected to the input to test it as you say.
Nope down to 79% and after plugging in the charger its still 79% an hour later. Guess I need to try a transformer with a higher VA 
Its such a pain trying to get this to work.
I use the same transformer as you.( from Screwfix). I only see the plug symbol. I have had no errors or lack of power (Yet) However, I use pins 1 & 2, which gives 8v & 1amp, not 24v which will only give about 0.33 amp. (Which is to low). So far mine is ok & the transformer hardly gets even warm.
Yes thanks. Looks like it is charging but just slower than I thought. Has jumped fro 78% to 80% 
I may try the 8v option to see if I get the plug icon though I am guessing it will step down either to 5V DC at a couple of amps inside the unit for charging the cells.
I was expecting to see the annimated % icon like when you connect it to the Homebase 2 via USB. Seems the plug icon is all you need to know its working. If the transformer is left on will the icon disappear once it finished charging back up to 90% ?
I also have a AC 18v 500mah three pin plug one with long fly leads made for video doorbells that displays the power icon as well when plugged in. That probably has a higher VA of 9 over this 8VA one so I now have the option to use either. The Plugin powersupply is probably easier than the fusebox transformer, though that seems better made/quality.
At least now I know it works
I guess if you had a lot of triggers a higher VA transformer would be rquired to keep up but I doubt I will have more than couple of dozen triggers a day if that.
Thanks for your help.
Just a note, on the above transformer, it’s misleading what it says about DC, it’s AC in & AC out. Theres no way DC would be coming out of that. While mine has been connected to it, I’ve not seen any percentages, I’ve only seen the plug symbol which is coloured green. Maybe it turns red or something if there’s a lack of juice going in, I just don’t know. Fingers crossed it works for all of us 
You are right the DC output spec quoted must be an error rather than AC. Anyway to confirm that it is definately charging. I tried changing it to 8V and as you say it charges at that as well. Strange I would have thought it would require a higher voltage. At the end of the day it must be down to the constant power/VA it sees. Will be interesting to see what it does when it gets to 90%, maybe the plug icon goes off ?
Hopefully it will continue to work as you say. Still not sure if to use this one or the three pin plug in one I have that is 18v 500ma. This consumer unit one is actually cheaper though I will need to get a 2 module unit box like this to put it in.
Yes I will be using that enclosure ( not in anything at the minute, just put safe for testing). It’s not a high voltage they need, hence they will slow charge from a phone charger which is only the standard 5v with 1 maybe 2 amps at most.
Yep mine is hooked up adhoc at the moment just to test like you
PS just for completion of the post, here is the 3 pin plug transformer that I can confirm also works with the eufy battery powered doorbell
Mine just shows a green plug.
I have a Hager st301 transformer on the consumer box running the existing legrand mechanical doorbell.
Reading the specs on this transformer it says rated for 30 minutes continuous usage.
Is the eufy battery doorbell technically always in continuous usage if connected to the wires?
No, it isn’t. If you have the app up to date, it should show the battery icon when it is not charging (on android at least).
When it drops below 80% it charges again up and about 85% or so (don’t have exact figures at hand)
