I am toying with a new door sensor: sengled smart window/door sensor (available on Amazon). It’s on a door that generally remains open and almost never moves. I’m surprised to be getting alerts that the battery is below 15% after just 6mos. Is being open a condition that drives battery usage? Thanks!
An open or closed condition won’t drive battery usage, unless of course it’s constantly being opened/closed, but that’s not your situation. Does that sensor report temperature? If so, perhaps that could be contributing to battery usage, especially if the temps fluctuates a lot. How old is the battery?
I typically see a couple years from my Iris zigbee sensors (CR2 batteries), and just about a year for a few of my Ecolink zigbee sensors (coin batteries). Those Ecolink sensors report temperature A LOT because I have them outside, which tends to drain them quicker than most of my Iris sensors. I also have a Gen 1 ST multipurpose sensor from way back that uses 2 AAAA batteries, and it’s on my mailbox. That thing is going on year 3 with the last battery change and it’s only at 25% as of today.
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It looks like the Sengled door sensor uses a CR1632 battery, which is very small and has only 130mAh. Compare to a larger CR2032 which is almost double at 240mAh. A CR2 like in my Iris V2 contact sensors is almost 780mAh.
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Battery life is based on the size of the battery, The operating conditions, and how many times the device is used.
If the device is in an area where it gets very cold or very hot, battery life will be significantly reduced (for most batteries, the optimal operating range is between 40°F and 90°F, but there is variation).
If the device sends a lot of reports, that uses up some battery life. For this reason you will generally get longer battery Life from an open/close sensor which only reports open and close events. If it also reports temperature every 15 minutes you have increased the device usage by literally dozens of times.
Additionally, the strength of the mesh matters a lot. If there is a pretty close Zigbee repeater, such as a plug-in pocket socket, message transmission will likely be reliable and not require much power.
But if the battery sensor is all by itself on the very outer edge of the range to reaching the next repeating device, it may have to transmit multiple times to get each message through. That chews up battery life as well.
(Also, you should not be using rechargeable batteries in these kinds of devices unless specifically recommended by the manufacturer. The reporting will be off and the performance may be as well.)
So the first question is how far is it to the nearest Zigbee repeater? And what are the operating conditions?
(Also note that Sengled devices do not repeat. That includes both the lightbulbs and their plugged in pocket sockets. This is unusual, but it’s a marketing decision that they have made.)
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I’m thinking this is the problem. I just installed one of these in November and it’s already showing 11% in SmartThings. However, it has been below 15% for weeks, so it could also be a matter of how the device reports battery and/or the way the DTH calculates the battery %. I’m waiting until it totally dies to determine the true battery life.
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It’s about 6 feet from the ST hub, with a wall between it and that
I’m thinking it too. The Amazon listing claims 2 yrs. Yeah, right. I asked the question on Amazon. We’ll see if the manufacturer replies. (And if so, I’ll post back.)