There are pros and cons to both of these devices, and some people might even want to get one of each.
The ecolink is battery operated, but must be placed within 6 inches of your existing smoke detector. And the default configuration only to text the smoke alarm – – if you also wanted to detect carbon monoxide, it will use up battery is much more quickly.
Note, that the sensor must be mounted within 6 inches of the detector with the microphone oriented toward the detector.
And although the marketing materials say:
instantly sends you a text or email notification
That’s not actually true. What happens is this device sends a notification to your hub. Any messaging comes from your hub, which, as we know, in SmartThings is a cloud-based operation.
The remotelync has to be plugged in, so you don’t have to change batteries, but your power does have to be working. It uses your Wi-Fi, not your hub, to send messages. The remotelync can typically hear a smoke alarm from several rooms away. There is a testing protocols so you can verify which alarms it can hear.
So if your power is on and your Wi-Fi is working, but SmartThings is being flaky or the SmartThings cloud is unavailable, the remotelync will be able to notify you when the ecolink cannot. You will get one cloud message that your power is out if the device becomes unreachable from its own cloud, and another message when the power comes back on. That’s similar to smartthings “hub is offline” message.
The ecolink doesn’t need power for itself, but your hub still has to be working or you won’t get the messages.
So neither one is as good as some of the ones that come with security systems which have battery backup and cellular communications, but either is probably better than nothing. And the ones that have cellular usually require their own models of smoke alarms, you can’t use your existing dumb system.