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Fast battery drain on a door contact sensor, sensor is reliable but the coin cell lasts no time

LanderAuclair

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Joined
Feb 1, 2026
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4
Has anyone else had a door sensor that’s reliable but absolutely destroys batteries? I’m still learning and I don’t know if I set something up wrong or if this is just normal for certain sensors.

A specific moment for me was yesterday when I opened the door a few times and noticed the sensor light blinking like it was working hard, then the battery warning came back later that day. Do you usually fix this by moving it closer to the hub, adding a repeater, checking if the hub is polling too aggressively, or just switching battery brands because some coin cells are basically scams?
 
Coin cells are a minefield. Make sure you’re using the correct type, and check the packaging date if you can. The “works for a week” pattern is often cheap cells or old stock, not the sensor. If you swap to a reputable battery and it improves immediately, that’s your answer.
 
Has anyone else had a door sensor that’s reliable but absolutely destroys batteries? I’m still learning and I don’t know if I set something up wrong or if this is just normal for certain sensors.

A specific moment for me was yesterday when I opened the door a few times and noticed the sensor light blinking like it was working hard, then the battery warning came back later that day. Do you usually fix this by moving it closer to the hub, adding a repeater, checking if the hub is polling too aggressively, or just switching battery brands because some coin cells are basically scams?
I don't know what button cell you are using. I do know that some people confuse the CR2025 and the CR2032 cells. The CR2025 will fit into a CR2032 holder but has less capacity than the CR2032. Is this your problem?
 
usually there's some bitter coating to keep kids from eating them, that coating can actually interfere with the contacts on some sensors.
Try wiping the battery down with a little rubbing alcohol or switching to other brand that doesn't use the coating
 
If it’s blinking a lot, it’s basically panic-transmitting...fix signal first and batteries second.
 
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