Remote freezer monitoring

I want to be able to monitor our home freezer temp while in the UK next month…it’s the hurricane season and we need to know if we were to lose power long enough for the freezer to thaw so we don’t eat spoiled and refrozen food.

Obviously I need a wifi enabled model that will send email of Bad Things happen…along with web accessible graphs so we can check what happened over time. Google has revealed a bunch of these…but I’m hoping someone has a recommendation for or against a particular brand. We don’t have any Alexa or Dot or any of the other members of the Amazon family of privacy obliterating devices…so somethin* tha5 works with email notifications and an app or web page for details is preferred. Suggestions anyone?

If your main concern is whether or not the food has thawed, a low-tech solution might be to freeze a container of water and put a coin on top. When you get back check whether or not it is on top or at the bottom.


Or just put a sealed and partially full leak proof container upside down after it is frozen. Maybe the coin idea is more foolproof though, no worry about leaks.

We always just look at the ice cream. It’s clear to see if it’s melted and refrozen.


I have a SensorPush with the Wi-Fi gateway. It has been 100% reliable for the past year. Super customer service, as well - I received one DOA sensor and a new one was overnighted to me. Easy to set up and use.

Depending on how much you’re willing to spend, maybe a sufficiently large UPS on your freezer would be a good option.

I’ve seen many blog posts and YouTube videos from people who like the EcoFlow Delta Pro systems. But that may be massive overkill - the big models can actually provide backup power for your entire home, and they’re priced accordingly.

But maybe you can find a unit (possibly from a different brand) that can can be suitable for your purpose.

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I use a Govee temperature measuring device in my motorhome when we are out and the dogs had to be left behind. Alerts me if the temperature gets above or below a threshold due to power loss. It and the wifi hotspot have adequate battery for the period.

Inkbird has a range of remote sensing devices. I use one to monitor a bath and start a heater/pump to maintain a constant temperature:

It does require you to give access to home wifi, which might be a security concern.
If only Apple Homekit was more versatile!

YoLink devices are excellent. They use LoRA instead of Wi-FI or Bluetooth so they are reliable. (Which is more than I can say for the many temperature sensors that I have tried.)

And they make a sensor specifically for this situation, which is good, as some general sensors will have difficulty getting a signal through the walls of the freezer when it’s closed.

I buy mine from Amazon, but here’s the company’s website info: Smart Fridge

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I’d second the positive experiences for Sensorpush devices. We monitor temperature/humidity for a number of laboratory incubators/freezers/chambers, and they have been very reliable. Notifications come up via an app on any IOS device, and multiple individuals can be notified, increasing the chances of someone responding in the middle of the night. In a laboratory situation, the only limitation is that the sensors don’t monitor temperatures below ~ -35C, but this won’t be an issue for a home freezer.

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Thanks to all for the recommendations…I will check all of them out. We do the coin on top of the block of ice thing but it’s a pretty coarse determination of what happened…given that we are gone sometimes during hurricane season we want to be able to determine whether the freezer of food needs to be tossed when we get back or not…if there’s a storm related power outage then there’s no real way to determine when power came back and how warm for how long the freezer got.

The UPS option for the freezer would really need a huge UPS depending on how long an outage we wanted to be able to withstand…in Ian we were out of power for 4 days and I can’t imagine the size and cost of one big enough to handle that…if we’re here then we power up the generator a couple hours a day to keep it frozen but just wanted to be able to figure out whether to toss the contents if we came back a month later.

Gordon…does the hub and app provide notification of alerts when one is away from home?

Jh6u…same question for the Sensorpush sensors?

I assume it works via the hub to send notifications to my iPhone…we’ll be disabling our AT&T SIM while in the UK and using either an eSIM or physical UK SIM and will have wifi obviously when we’re in the hotel.

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The hub allows you to receive sensor notifications via email, sms, or push notification to the YoLink app. (Or, all three at once!)

Thanks Gordon…always nice to get good advice from people you trust instead of random people on the internet…well, I guess Tidbits Talk members are random people on the internet but they’re obviously more reliable than your average everyday random people.


And in another blast from the past… I still use mine and in fact need to go change a battery in the fridge sensor right now.

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I know when my power goes out due to my UPS software. I have a UPS on my cable modem and networking gear. It also protects my file/media server. When it switches to battery power it sends me an email alerting me to the loss of power. When my backup generator kicks in it sends me another message that power has been restored. When power is restored and stable I get another set of alerts when the transfer switch goes back to the utility power. It also gives me a record of when the power went out and for how long.

Another slightly more accurate and costly method would to get a digital thermometer with either a built-in or temperature probe with the display showing max high and low temperatures and placing the probe or unit in the fridge as appropriate. Then when you get home check the high temperature reading. This is more accurate as the temperature might rise to be high enough to start the food thawing or continuing thawing but not high enough to cause the water with the coin to totally melt. If you do use the coin method I would recommend using a very small dish such as a small food prep bowl, shot glass or condiment cup with around a ¼" of water above the container bottom for a quick reaction time. You want just enough water to be able to sense the coin drop but also enough to account for the sublimation of the ice, especially in freezers with automatic defrosting.

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That works but it isn’t just the temp it gets too but a combo of that and how long it was there that determines whether you toss the contents or not…but it is a relatively inexpensive solution.

UbiBot is what you want

I use a coin and UPS power supply modified to connect to two 12 VDC car batteries connected in parallel. Sits right next to the freezer and with the table over it, I can use out as a perch to put stuff on when loading and off loading. In theory, It will last 14 days. I give it 7. My freezer is a very efficient one that has a max draw of 170 watts where in maintenance mode. Most small UPS devices haver a limit of 500 watts Mine is 480 and not came with two 6 VDC NiCd batteries wired in series. If they had been in parallel, I would have use golf cart batteries.