Had my DW2’s (two pieces) since May 2022, today both batteries are dead. Latest firmware, only local MQTT, static IPs and only checking if door is open or not. Nothing else.
One batterypair is near death apparently (flickering red light with weird static noises). The other is really dead.
Now I need to buy 4 expensive new batteries… did not expect this.
Strange.
I’m using open/close and tilt. Static IP (set in shelly), time server set to local router
And it lasts very long.
Make sure you have disabled wakeup by lux changes
Edit: And make sure you have recent firmware. v1.11.8 is the most current and fixes several minor issues with communication with mqtt effectively shortening the time when the device is woken up.
I did, nothing special (no lux, no tilt, static IP, most recent firmware etc). Send one back because I thought it was broken, but apparently the batteries after 3 months. Home Assistant reports the last battery to 64%, after checking them out, they died…
I don’t know if I have one sensor that is defective or not, but I have replaced the battery 2 times after 3 months of used. From my experience using them, it is not very user friendly. I can’t get to the gui menu without waking up the sensor which only last about 1 minute or two.
it’s correct. otherwise it would drain the battery.
how long it takes to connect to the wifi?
Ideally it should be about 2 secs.
If you enable led, you can measure how long takes to report state change. it should take fraction of the second
we may compare settings of my device and yours
There is nothing to compare as the battery is dead. We’ll have to wait until I am able to replace them, as these aren’t common batteries (AA or AAA).
I have a bunch of DW2 throughout the house and had to replace all batteries within nine months, which is expensive since two A123s are needed per sensor.
I love the Shelly (mains powered) switches but would refrain from buying battery powered devices from Shelly for the time being. And yes, I use them without wakeup by lux changes but with wakeup for temperature changes of 1° and with tilt and vibration enabled.
Maybe the batteries would last longer with “all the good stuff” disabled, but for a dumb window sensor I would not spend that much money and would use ZigBee instead of WLAN - my subnet is crammed and I’m running low on IPs…
Does anyone know how to lengthen the timeout for the battery powered Shellies (21600sec)?
When a sensor approaches battery failure, the sensors start to become partially unavailable: the binary_sensors remain but all sensors report unavailable.
Any way to circumvent this?
I’m pretty sure sensing the temperature will eat the battery.
I have several H&T sensors and I can see that batteries’ service life depends on how much and how often the temperature changes (which is obvious). The sensor located near the window obviously will eat the battery a lot.
Saying that, if I would have to buy temp sensor today I would look for zigbee. Not sure however how well they are calibrated (probably I could shift readings in Z2M though)
Besides of above, DW sensors stay working without replacing batteries for 2 years right now. Cannot confirm DW2 yet, since I own them for a shorter time. But they managed already a year with contact and tilt only enabled.
I’ll share my experience with this sensors and with Shelly. Spoiler alert: is not a good one.
I recently bought 10 Shelly door/window 2 sensors. Before even starting with the review, let’s say that this is an expensive product. At the moment is sold for ~27€, plus shipping. The more you spend on their shop the more you pay for shipping, there’s no free shipping. Batteries are not included and are not cheap since they use 2 x CR123A batteries. The battery they recommend is listed above €4 on their local distributor website, so you add another ~9€ to the initial 27€ + shipping.
The battery cover is not easy to open, I needed a screwdriver to push out the plastic lock. If you hold the plastic cover of the sensor on the wrong point, you’re up for a surprise. They used a Reed switch to detect the magnet and they placed it very close to the plastic cover. Instead of using a switch enclosed in an epoxy/plastic package they used the cheaper version that comes in a glass tube, so if you push the plastic case you’ll break it. If you don’t realise it’s broken before putting the batteries in, it will create an arc and it’s a fire hazard, CR123A are lithium batteries and they can start a fire if overheated.
Of course the sensor is gone forever as soon as you break the Reed switch.
Let’s go back for a second to the batteries. I didn’t want to spend €100 on batteries every year or even weeks (see comments above), so I bought rechargeable CR123A batteries. Long story short rechargeable CR123A batteries have a slightly higher voltage than the disposable ones (both are in the 3V range though), and that was enough to kill half of the devices, while the other half was working ok. I contacted Shelly and they refused to replace the faulty devices under warranty. To note that nowhere on the Shelly shop is stated that rechargeable batteries should not be used, nor it is listed the sensor’s maximum voltage that should not be exceeded.
Funny thing is that they updated the “knowledge base” page of the sensor saying that rechargeable batteries should not be used AFTER they refused to replace my sensors. Well, you can either admit that you left out critical information and replace the devices under warranty, or refuse and claim that there’s no defect or missing documentation. You cannot say that you’re not at fault and then update the product documentation post sale to try to cover your ass.
In any case I believe that the end user is not supposed to be familiar with voltages and charging cycles, and the producer is responsible of providing compatibility with rechargeable batteries of the exact same model and dimensions of the disposable ones. This is specially true if they do not indicate any limitation or incompatibility with rechargeable batteries. It’s the first time I see a device being destroyed by rechargeable batteries of the exact same type of the disposable ones.
I’m gonna skip on the sustainability issues on forcing users to buy expensive disposable batteries every year.
Open points that I still need to double check or that I don’t like:
There are other things that I didn’t like when buying from them. They charged me and marked as shipped an order on their website and only after a week, after I asked for information, they actually shipped it. If I had know that, I wouldn’t have ordered because it arrived too late.
On the plus side, I own and use several Shelly relays and energy monitor relays and they all work fine, but I think that’s no excuse for treating customers like that. To note that I spent over a 1000€ on their products, but they didn’t seem to care about keeping me as a customer or about me sharing with the community my experience.
I was gonna buy several of their temp+humidity sensors, also quite expensive, but I decided I’ll take other BT sensors that will be flashed with BThome.
Just thought I’d add my two-penneth on these Shelly Door/Window contact devices following a year working with several… I have had multiple failures with these devices - and it’s always the actual relay failing. Shelly will NOT admit this is an issue but come on - given that I’ve got through at least FIVE in 12 months??? Yes it might be something dumb I’m doing but frankly if I am I’d surely have an idea what it was by now! Actual failure to connect to the network etc is never an issue, indeed they work right down to ridiculously low wifi signal strength. No, always it’s a relay fail - last night we were woken by an alarm at stupid o’ clock. The app reported our pool plant room door was open. We didn’t even bother to get up and check it and sure enough this morning I found it’s yet another relay failure. I examined the device and it appears normally on our network, reports heat and light parameters instantly as the door is opened and closed, however the relay stays in the open state all of the time - same old, same old. I got so p*ssed off with these devices; after all I was relying on them for my home security, that I went to town on Shelly and they eventually gave me a refund for 5 of them. But today another has died!
Then there’s the issue of battery life - they EAT batteries at a most alarming rate - in 12 months I have had to replace the batteries (which are bl**dy expensive too!!!) on FOUR out of six contacts I have fitted, and one of the contacts has actually had TWO battery changes! So much for the low battery usage Shelly boast for these devices.
No, if I can add just one piece of advice based upon extensive expensive experience of this device I would say spend your money elsewhere because they are costly to run and at best, grossly unreliable.
My experience / review:
I purchased two Shelly DW2s on September 5, 2021. $46.80 for a two pack, plus $8.80 shipping charge for a total cost of $55.68 USD. I received them on September 10th. A six pack of CR123A 3V Lithium batteries cost an additional $25.74.
I installed these to monitor two garage doors - open / close status only (temp, tilt, lux were nice to have but not needed). The installation was disappointing because:
Actual use was fine but battery drain was bad enough to ensure they would not last the advertised 2 years. A search of this forum and Github confirmed that turning off the majority of the sensors and triggers should conserve battery life.
Then one of the DW2s started to intermittently go “unavailable” around January (5 months after installation). I found and contributed to an existing issue on GitHub (Shelly Door/Windows sensors appear unavailable after some time of idle state · Issue #60123 · home-assistant/core · GitHub). In summary: batteries lasted ~5 months (with everything set to conserve power), the battery sensor is very inaccurate (ex. 85% battery = 0.0 to ~2.7 V = dead battery), and the “root cause” was attributed to either a network problem or firmware bug (and/or possibly a hardware failure - more on that later). I have a proven solid network and the packet loss was due to dying batteries.
In addition to the batteries lasting only 5-7 months for each DW2, both DW2s have failed and needed to be replaced, firmware updates have failed for unknown reasons, troubleshooting sometimes requires factory resets then suffering through setup again (and sometimes removing then re-adding them to HA).
These are the most unreliable and difficult devices I own.
I am very disappointed in the DW2s and I would not recommend them.
Finally, I own, and I am very happy with, and I would recommend, these devices:
I totally agree these are rubbish. NOT TO BE RECOMMENDED AT ANY COST