I’ve recently bought the duel Homebase doorbell and connected a 18v 500ma transformer which the manufacturer states is compatible with my eufy doorbell. Initially once connected I saw the green plug symbol which I thought was correct keeping my doorbell fully charged. However, over a couple of days with moderate use ( mainly motion detection) I’ve noticed the battery power level has slowly depleted to 96% and the battery indication has changed from a green plug to a charging icon.
I will continue to monitor the performance of the battery/transformer and give an update in a month or so!
Will be looking for an update.
The way I see it as working, the transformer will charge the battery and also power a mechanical chime (if you’re using one). The plug icon and battery charge icon I would assume would switch back and forth depending on the charge of the battery. There’s probably a threshold to tell the transformer to start charging the battery when at a certain low percentage of battery charge is detected. Thus the icons would then switch back and forth _ you wouldn’t want the battery to be at 100% charged all the time, this would damage the battery.
The transformers only trickle-charges the batteries, so it is possible to lose charge while connected to the transformer. Eufy calculates normal use as 10 detections a day and 30 seconds recording for each. The transformer charges the battery to replenish that amount of use each day. If you have more detections and or longer recording it will use more energy and you will draw down your batteries. They also cycle the charge so as not to stay at 100% for long periods.
If you use excessive amounts of battery, you can set the sensitivity lower to reduce detections or reduce the recording time for each detection.
I would monitoring your charge percentage and number of detections per day if you want a good feel for how your doorbell is working.
Also, if you live in a climate that gets cold for long periods of time, the doorbell will reduce and cut off charging once temps get below 0 F to avoid destroying the batteries, so make sure your doorbell is fully charged before temps drop.