Battery Life On One ZWave Lock Is Terrible. How to diagnose? (with charts!)

See the chart above? The yellow-ish line that is seen dipping, the rising, then precipitously dipping again is the battery level on one of my Yale zwave deadbolts over the last 5 months. The rise represents me changing the battery out about 2 months ago.

I have 3 of these locks. Only one is showing the issue. It doesn’t get that much more use than the other 2. How do I begin to diagnose what is going on?

Check the configuration on how frequent the device checks in (wakes up), any chance the signal is bad at it’s location?

Check the battery contacts aren’t dirty/corroded and that the springs contacts are making good contact.

Try swapping the battery with one of the other units. If the problem follows the battery it could just be a bad battery.

Excessive friction can cause faster drain as well (at least on my Schlages). Check to make sure the bolt moves as freely as possible.