Energiewende on Smart Home? Sure — But Secure!

OBI Energy Tracker – For Beginners AND Home Assistant Pros

Thu, 23 Jul 2026 00:00:00 +0000

OBI is selling a small electricity-meter reader right now for under €15 – and I’d argue it’s a small sensation. At that price there simply hasn’t been anything comparable, neither for beginners nor for advanced users. In this article I’ll show you two things: whether the OBI Energy Tracker is worth it for beginners and what the app can really do – and how to get the data into Home Assistant, with the OBI cloud, but also completely without the OBI cloud and app.

How I even got hold of the device: a friend forwarded me the heyOBI newsletter about the Energy Tracker and asked if I wanted to take a look. I thought it sounded interesting, and he put me in touch with someone at OBI – that’s how I ended up with my test unit.

Disclosure: The device was provided to me by OBI free of charge. No fee, no requirements – my opinion stays my own. Links marked (paid link) are affiliate links.

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The problem: smart meters in Germany

Smart meters and Germany – that’s an absolute disaster. Only about 5% of all meters in this country are so far a real smart meter, even though it would have solid advantages for both sides.

Most of us instead have a simple digital meter – in technical terms a modern metering device. An important distinction, because it often gets mixed up: a real intelligent metering system, i.e. the actual smart meter, is that modern metering device plus a gateway that sends the data to the grid operator on its own. That gateway is exactly what most people are missing – they only have the optical interface on the front to read the data out locally. And yet the question nags at anyone with a smart home: where does all the energy actually go?

What is the OBI Energy Tracker?

The device consists of two parts:

a sensor that is magnetically placed on the optical interface of your meter, and
a bridge that receives the data via radio (868 MHz) and passes it on to your WLAN.

The official retail price is €30, but right now you can often get it for around €15, sometimes even cheaper in promotions.

👉 OBI Energy Tracker at OBI (paid link)

Why it’s interesting

What was there comparable so far? The best-known candidate is the Tibber Pulse – but it costs around €130 for non-Tibber customers and is only usable in a limited way without an active Tibber electricity plan. Or the classic DIY route: an infrared reading head with USB on the meter, plus a Raspberry Pi and a rather crude console tool (Volkszähler / vzlogger). It works – but it’s not for the masses.

For €15, a beginner gets a finished app, while the advanced user gets a device that can even be pulled completely locally into the smart home (more on that below). A Shelly Pro 3EM can do more, but needs an electrician and DIN-rail space. The OBI is the simple, cheap way in – without touching any wiring.

Setup and the OBI app

The first curiosity: the feature is tucked into the completely normal OBI app, which at first feels like a shopping app. Only under Profile does the Energy Tracker show up as its own item. Unusual – but it works, and pairing the bridge and sensor is straightforward; every step is explained in the app.

Unlocking the meter (PIN from the metering point operator)

One point where many people get stuck: many digital meters only release the optical interface once you unlock them with a PIN. You get it from your metering point operator – you even have a legal right to it, but you have to request it once (many offer a contact form for this).

A tour of the app

The overview immediately shows the status of bridge and sensor. The consumption analysis is really well done for beginners:

at the top the absolute meter reading, separated into consumption and feed-in,
a daily overview as a bar,
an analysis view with day/week/month and the trend as a curve,
and – for those who don’t need it that precise – aggregated four-hour blocks (morning/afternoon/evening).

CSV export

The data can be downloaded as a CSV and analysed further in a spreadsheet. The values are provided in five-minute intervals. In my export you can nicely see the solar bell curve of my PV system (over 5 kW of feed-in around noon, with dips from passing clouds) and the big load blocks when the EV charges.

Standby analysis – handy, but with a caveat

I find the standby analysis especially interesting: on a completed day the app shows the standby consumption – not just in watts, but also as a share of daily consumption. Very vivid for getting a feel for your own base load.

An important caveat from an “…but secure” perspective: the sensor measures at the grid connection point – it only sees what flows between you and the grid, not what happens behind the meter inside the house. If, like me, you have a PV system with a battery, the battery covers the base load at night and almost nothing shows up at the grid. So the standby figure is mainly meaningful for households without a battery. If you have a battery and want a clean reading, it’s best to disable it for a day.

Firmware update

At the start a firmware update was pending – it ran in the background and was simply done after a few minutes. Nothing a beginner stumbles over.

Interim verdict for beginners

For beginners the device is absolutely solid: cheap, simple, and the app does its job.

Credit where it’s due: the Data Act page

Despite all the criticism of cloud solutions, one thing I find genuinely great: OBI has its own Data Act page. It states completely transparently what the device does and how it communicates – encrypted via MQTT in JSON, meter readings every five minutes, roughly 19 MB per month in total. Even the exact values that are read out (consumption, feed-in, current power) are listed, and only the technically necessary data is stored on the device itself. This openness is a requirement under the EU Data Act – but very few manufacturers implement it this cleanly. A big compliment for that.

In Home Assistant: the easy way via the cloud (HACS)

Many of you run Home Assistant as your smart home hub and want the values right there. For that, there’s an unofficial integration in the Community Store (HACS): install it, enter your heyOBI credentials – and your meter readings show up as sensors in Home Assistant.

➡️ hacs-obienergytracker-integration (GitHub)

The catch: this integration doesn’t get the data from the device, but from the OBI cloud. It logs in with your heyOBI account and queries OBI’s server. So without the cloud nothing works, and if OBI changes the interface, it breaks.

Completely local – without the OBI cloud

For anyone who wants to be truly independent, there’s another project: OBI Energy Tracker Local Cloud by Aaron Christophel (atc1441). The community has fully reverse-engineered the device. With it, you can redirect the bridge so that it no longer sends its data to OBI’s servers (on AWS), but directly to a server at your home – and if you want, you can even flash your own open-source firmware onto the device.

Roughly sketched: the meter provides its data optically to the sensor, which transmits it over 868 MHz to the bridge, and the bridge normally opens an encrypted MQTT connection to the cloud. Because an openly documented AWS IoT protocol is used here, you can point the bridge at your own local server – for example next to Home Assistant on the same Raspberry Pi. Optionally, an open-source firmware replaces the OBI software entirely, flashed via the normal update mechanism, without opening the case. The result: the tracker runs completely offline, in real time, directly in Home Assistant.

Rebuilding this step by step would go beyond this article. Want a detailed guide? Then write “local” in the YouTube comments – if there’s enough interest, I’ll turn it into its own video, from redirecting the cloud to proving that really not a single byte leaves your network.

What OBI is planning next

Good news to finish, especially for those who don’t want to tinker themselves: according to the OBI FAQ, an official integration into smart home systems (Home Assistant, OpenHAB, FHEM) is “firmly planned” – in OBI’s own words, “our heart beats for open source”. On top of that, multiple sensors on one bridge should become possible soon. In the heyOBI newsletter, OBI additionally announces a live mode with per-second values and a consumption comparison with other households. So a lot of what’s still community tinkering today may soon arrive officially – and then this little device gets even more interesting.

Conclusion

For under €15, the OBI Energy Tracker is a surprisingly good way to make your own power consumption visible – with a clean app and exemplary data transparency. The cloud requirement and the still-missing official HA integration are the weak spots. For tinkerers, though, the ability to run the device completely locally is exactly what tips the scales.

👉 Buy the OBI Energy Tracker at OBI (paid link)

Note: Links marked with affiliate link are affiliate links. As a partner of Amazon and OBI (via the Awin network) I earn from qualifying purchases. This means I receive a small commission if you purchase through these links — at no extra cost to you. The revenue helps me run this blog and YouTube channel and keep creating content. Thank you for your support!
― Joachim

3,500 km EV Road Trip: Charging with a Portable Wallbox

Thu, 16 Jul 2026 00:00:00 +0000

Four weeks, 3,500 kilometres, a fully electric car – from Germany through Austria and Italy all the way to Croatia and back. The big question upfront: is this relaxing, or is charging on holiday pure stress? My joker in the luggage was a portable wallbox, the go-e Charger Gemini flex. Here’s what I learned about charging from strangers’ sockets along the way – including the moments when things didn’t go smoothly.

Transparency: The go-e Charger Gemini flex was provided to me by go-e free of charge as a permanent loan for this test. (Ad)

⚠️ Note from go-e: According to the operating and installation manual, the go-e Charger Gemini flex must be used hanging vertically, or mounted vertically in the included wall bracket on a flat wall. I didn’t always handle it that way on my trip; I’ve marked the relevant spots in the video. Please don’t copy this.

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How this came about

A bit of backstory, because transparency matters to me: go-e didn’t come to me – I reached out to them. I’d thought the go-e Charger was genuinely great long before this. My parents-in-law have been using one for ages, though in their case the hardwired version on the wall. When the road trip came up, I figured it was the perfect match: test the portable version in real travel life for a whole month and show it here on the channel. Hard to beat that.

Which is why I was all the more pleased that go-e was completely open to supporting me – and my still fairly small channel – with the wallbox. That’s also exactly why this video isn’t a paid-for puff piece but my honest travel report: everything that worked, and the moments when it didn’t.

What actually matters: the cost

At a fast charger you quickly pay around €0.80 per kilowatt-hour on the road. At a private socket in a holiday flat, it was often just around €0.10 at night here in Croatia – and in some places the electricity was even free. EVs simply aren’t the norm there yet, and hosts are correspondingly relaxed about it.

I kept a log over the four weeks: all told, I saved over €280 compared to what fast charging would have cost. Over an entire holiday, that’s a real difference.

Charging from an unknown Schuko socket: how many amps are safe?

The most common case on the road is the ordinary household socket – the Schuko. The immediate question is how much current you can reasonably draw from it.

go-e recommends 6 amps for unknown sockets. That’s the safe bet – but on my Cupra Tavascan (77 kWh) it means roughly 33 hours from 20 to 80 percent. The full 16 amps you should never draw continuously from a normal Schuko: it isn’t built for that and can overheat over time.

I wanted to know for sure and had my thermal camera with me:

First flat, overnight at 10 A: 6 A brought the socket to about 25 °C, 10 A to around 30–35 °C – both perfectly fine.
Second flat, even at 12 A – but there was a dedicated Schuko with its own fuse and RCD, mounted in the garage specifically for the car.

Rule of thumb without a thermal camera: if you touch the Schuko plug after an hour and it’s hot, something is wrong – dial the charging power right back.

I show what Schuko charging looks like in thermal view as one of five use cases in the thermal camera video.

More than Schuko: the adapter set

Schuko isn’t everything. The go-e Charger comes with an adapter set of three adapters, and that’s what makes the box truly flexible:

Schuko adapter for the normal household socket.
Blue camping plug (blue CEE) – familiar from campsites, found almost everywhere there, and rated to deliver 16 A continuously.
Red CEE adapter for industrial power sockets. Important: not every red socket is the same – some are for 11 kW, some for 22 kW, and they differ in size. That’s what the red-to-red adapter in the set is for.

Control via the app – local, no cloud

The box is controlled through the go-e app. The nice part: it opens its own Wi-Fi hotspot – you need no internet and no cloud, everything runs locally.

One pitfall cost me some nerves early on: your phone has to be on the box’s Wi-Fi, otherwise the app can’t find the box. If you’re also in range of the holiday flat’s Wi-Fi with internet, the phone happily prefers that one – and the box is “gone”. When in doubt, quickly check which network your phone is actually on.

A word on the charging log, in case you want to settle up with your host: the box does keep a log, but on the road it has no network and therefore no date or time. For our billing we simply used the car’s charging log instead.

Safety & practical details

LEDs can be switched off – handy when charging in a publicly accessible car park where you don’t want the box drawing attention at night.
Cable locking at the box – so a spontaneous theft isn’t easy.
Built-in RFID reader: you can set the box to charge only after authorisation with the included chip.
Unplugging order: always pull the Schuko plug only once charging has stopped. The Type 2 plug at the car is locked and built to be disconnected under load – the Schuko isn’t. Pull it under load and you get small arcs that can destroy the socket over time.

The glitch in Split

Of all places, at the dedicated socket in Split the charge stopped abruptly one night – the go-e app said “phase not available”. First thought: is the box broken? It wasn’t. At the same time there was a heavy thunderstorm and a brief power cut. I only noticed because the car automatically pushed a notification to my phone. Restarted the charge, everything ran normally again.

The lesson: if a charge cuts out, don’t immediately blame the box – often the power source is the culprit.

Too bulky for travel? The dual benefit

Yes, the box is bigger than a plain charging cable. But the point is: you only need one wallbox. At home, have an electrician fit a blue or red CEE socket and run the box on its included wall bracket as a fixed installation. When you head off on holiday, unplug it and take it along. No second purchase.

Verdict

Does a portable wallbox pay off for travellers? After 3,500 kilometres, a clear yes for me. I was independent of public charging infrastructure at every stop, charged far more cheaply and could top the car up overnight – almost like at home. There are a few things to keep in mind, but comfort and savings combined won me over.

If you want to take a closer look at the go-e Charger Gemini flex, you’ll find it on Amazon in the 11 kW version* (the one I used) and the 22 kW version, plus the matching adapter set.

* Links marked with an asterisk are affiliate links. As a partner I earn from qualifying purchases – at no extra cost to you.

Thermal Imaging in the Smart Home: 5 Use Cases

Thu, 11 Jun 2026 00:00:00 +0000

A thermal imaging camera sounds like professional gear for thermographers or energy consultants. But as a smart home enthusiast, I use one for all kinds of things: checking electrics, finding hotspots in devices, inspecting my solar array – and making problems visible that all my sensors in Home Assistant simply cannot detect.

Transparency: The Thermal Master P3 was provided to me free of charge by the manufacturer – with no conditions on the content. (Ad)

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What a thermal image actually shows

The color gradient from blue to red shows temperature differences – but relatively: the coldest spot in the image is always blue, the warmest always red, whether we’re talking 20 or 80 degrees. For context, the camera displays the warmest and coldest spot as absolute readings, plus the exact temperature at the center of the image.

One detail shows how sensitive it is: the imprint of my hand on the desk was still visible seconds later – from body heat alone.

The Thermal Master P3 offers a resolution of 512×384, a focus ring for close-up and distance shots, and a dual-image mode that overlays the thermal and the visual image.

Use case 1: Checking Shelly flush-mounted boxes

Behind one of my light switches sits a Shelly 1 Plus for the underfloor heating. From the outside everything looks normal – but the thermal image shows 25 degrees on the outside of the box, with an ambient temperature of 21 degrees. Inside it’s definitely more – otherwise nothing would be measurable outside.

It’s not dramatic – but Eco Mode makes the difference visible: it throttles the Wi-Fi chip during idle periods, and the outside temperature drops to 23 degrees. Less heat means less power consumption and, above all, slower aging of the electronics. I’ve personally repaired Shellys with failed capacitors before. What goes wrong during installation – from too little space in the box to the wrong tools – I cover in a separate article: 5 mistakes almost everyone makes when installing Shelly.

Use case 2: Exposing standby power hogs

In the thermal image: a box, clearly warmer than its surroundings. In the visual image: my Sonos Play One – 3.8 watts in standby, officially stated by Sonos.

For comparison: in 2010 the EU mandated that household devices may draw a maximum of 1 watt in standby. The Play One launched in 2013, but as an audio device with active network standby it falls under an exemption – a loophole Sonos is happy to use.

With five of them in my home, that means 20 watts around the clock: 175 kWh per year, roughly 50 euros – just for standby. I now deliberately disconnect them from the mains.

Use case 3: Comparing thermal design – Raspberry Pi vs. Zimaboard

On a Raspberry Pi 4 under load you immediately see chips and voltage regulators heating up in concentrated spots – the heat piles up at individual points. Small stick-on heat sinks barely make a measurable difference.

The Zimaboard 2 with its massive aluminum case shows the opposite: no sharp edges in the thermal gradient, no hotspots – the heat spreads evenly across the entire enclosure. The chip isn’t any cooler, but the energy is dissipated in a controlled way.

That’s the real value of the camera: you don’t just see whether something is hot – you see how a device handles heat.

Use case 4: Checking the solar array for hotspots

A neat effect: solar modules appear cooler than their surroundings in the thermal image – solar cells convert light into electricity rather than heat, and reflect part of the radiation.

What stands out are “blotches”: irregular heat patterns on individual modules. That’s a warning sign – it could be a cell defect or just dirt. In my case it was harmless (a sun reflection during filming), but the principle holds: otherwise your yield quietly drops without any visible reason from the outside.

A once-a-year scan of the array – a use case that pays off for every solar owner.

Use case 5: Charging an EV from an unknown Schuko socket

On my road trip to Croatia I charged my EV from a Schuko socket at a vacation rental – an unfamiliar electrical installation of unknown age and dimensioning. Schuko sockets are not designed for continuous full load at 16 amps.

My approach: start at the mobile wallbox’s minimum (6 A), check the thermal image, then step up to 10 A. Wallbox and charging cable visibly warm up – that’s just physics. A look straight into the socket (cable briefly unplugged): warm, but well within limits. Continuous charging at 10 A was no problem at this socket.

Without the camera I would have either charged far too cautiously or simply hoped for the best.

Conclusion

Heat is, in the end, nothing but wasted energy – and a thermal camera makes it visible before any sensor does. For smart home users with their own electrics, a home server, a solar array, or an EV, it’s a tool that pays off surprisingly often.

Deal (until June 28 only): The Thermal Master P3 is €45 off on Amazon* – discount code THERMALCM10. According to the manufacturer, the best price this year.

* Links marked with an asterisk are affiliate links. As a partner I earn from qualifying purchases – at no extra cost to you.