Eufy 2K Battery Doorbell 16.9V Hardwired, "...Off, Low Battery"

Fresh installed 18 days ago. Hardwired with 16.9V measured across doorbell terminals.

Solution: “The Dance”…disconnect the doorbell from the 16.9V & reconnect again.

Wondering about:
Reliability of this device, will it work when I need it?
How frequently do I have to do “The Dance”?
Other issues abound with Smart Integrations.

Sounds like your transformer isn’t sourcing enough current to keep the battery charged. I have one thats been set up for 3+ months and every time I check it, it reads 85-90%. Its not the device, its the source.

Specs for the required transformer are 18-24 VAC @30 VA. Most older construction used 10VA rated transformers and that is not enough to keep the doorbell charged and operating. It will gradually suck the battery down over time and eventually give you the error.

Yep, Broan C905N Xformer with 10VA nameplate. Interesting “gradual”…took 18 days of use, 102 events (not all video), far cry from the claimed 180-day battery life w/o AC charging.

Thanks for your insight, I think you are probably correct on the 30VA. I see some other posts on this issue.

Thanks again.

I’m on 8VA without problems, doorbell is always charged.

I had one on my doorbell and did some testing. 8-10 VA is right on the edge. If the device gets a lot of traffic, it won’t work. If it gets 3 or 4 hits a day, it might work, but more than that and a lot of doorbell presses will push it over the edge. That’s why Eufy recommend 30VA.

The wired doorbell takes 400 ma. each time the bell is pressed, so assuming the wireless is in the same ballpark, that will deplete the battery faster than a bunch of push notifications from motion detection.

Never had the situation you’re talking about. With plenty of events and activity, it never stopped charging or anyhting.
Also,the manual states 8-24V AC for the 2k battery-doorbell.

I measured the 16V output connected to the doorbell, w doorbell “turned off due to low battery”:
50mA for about 10 sec.
25mA for next 10 sec,
3 mA finally continuously.
I assume the logic in the charging circuitry is responsible for the step function in the current draw.

Just a single 18650 cell has a 3400mAh capacity, so " 400 ma. each time the bell is pressed" should be good for 8-1/2 hrs of continuous pressing, if I got that right? My T8210 has a 6500mAh battery =>16 hrs?

An Anker Forum post recommended this 40VA xformer. Should be getting delivery on it tomorrow, and install the next day. Good test if it is indeed the source or a charging circuit defect.

Just to conclude this journey, the original doorbell likely had a defective charging circuit. Eufy was good enough to exchange the original with a new doorbell. It’s been 18 days since the new doorbell was installed, and has maintained about 90% charge state. I suspect Eufy only charges to 90% to optimize the service life and number of charging cycles of the Li-ion cells, 85%-25% cycling recommended.

I did replace the 10VA transformer with a 40VA xformer, but this is likely a “red herring”. The 50mA charging current was well within the capacity of the 10VA unit.

So all is well the power functions of the new doorbell. And again, Eufy support was good and efficient. Highly recommend their support team.