Difference Between 110 Volt Powered Devices and Battery Powered Devices

Not all Z-Wave devices are created equal. We can see this when we look at always powered devices (hard wired devices typically powered by 110v) and devices that are only powered by batteries. There are some pretty big differences that need to be taken into account for a successful install. 


Lets start with 110 Volt powered devices. Some products that will fall into this category are light switches, thermostats, scene controllers, and plug-in modules. All of these devices, when added to a Z-Wave controller, act as range extender. Your Z-Wave Hub will take into account all of your 110V devices and create routes for data transmissions which allow you to reach 200+ feet in range. All of these devices are constantly being polled (AKA Pinged) by your hub for status updates. Your hub will go down its device list; switch 1, switch 2, switch 3... and ask for each devices status (see Polling vs Instance Status). For example if you manually turn on a light and your Z-Wave Hub polls the light switch, it will know that it has been turned on. 



These devices need to conserve battery power and they do this by spending most of their time sleeping, similar to a computer being in hibernation mode. Battery powered devices do not repeat Z-Wave communications because it would take too much battery power. Typical battery powered devices are window/door sensors, motion sensors, and water sensors. (Door locks and thermostats are a different subset of battery powered devices that we will further discuss in our next section). The typical schedule for one of these sensors listed above is to wake up and check in with your Z-Wave hub every 60 minutes and then return to a state of sleep. When the device checks in, it tells the hub that it is communicating properly, while also checking if the hub has any updates for associations and parameters. All battery powered devices have a way to manually wake up/ become active by opening the battery lid or setting off the tamper sensor. Each manufacture is different and will post wake up methods within instructions. During initial setup you will want to make sure the battery powered device is awake transmitting new data to your Z-Wave hub. If you do not allow the device to transmit fully during initial pair you will witness intermitted functionality. 


Door Locks and Thermostats

Z-Wave Door Locks and thermostats have a built in protocol (command class) named Beam. Beam allows you to instantly wake up a device to send it a command. Locking a lock or changing the temperature on a thermostat are examples of sending commands. For example, you have a vacation rental property and you're getting it ready for a new guest. You log into your Z-Wave Hub to change the door code; within seconds the door lock wakes up and receives the new pin code. Without Beam you would have to wait for the lock to wake up which could be a very long time. One more thing to note is in order to use "Beam" the rest of your repeating devices in your Z-Wave network need to support it.