




PowerMon-E - Ethernet / IoT Advanced Battery Monitor / DC Power Meter with data logging
Features
- Dual 64V voltage inputs, allowing it to work in 12V, 24V or 48V systems
- Measures over 1000A using any external shunt
- Can drive a relay for remote ON/OFF, low-voltage disconnect, high-voltage disconnect, over-current disconnect, low-temperature disconnect, battery protection, generator start, and more.
- Ethernet, fully configurable, access it over the Internet
- Data logging that can store up to 3 years of data history
Description
Designed and assembled in USA.
This product requires an additional shunt.
This is an Ethernet based battery monitor. You can monitor the batteries in your RV, camper, boat, or solar system remotely, from anywhere in the world. All you need is a connection to the Internet and the freely available PowerMonX app for iPhones and Android mobile devices.
PowerMon-E is an affordable, high-tech solution for monitoring electrical systems. Whether you're in an RV, camper, or boat, utilizing solar power, or managing off-grid setups, PowerMon is designed to meet your battery monitoring needs. Remotely monitoring DC circuits has never been easier!
You can use your Apple / Android phone or tablet with the PowerMonX app to access the battery monitor. You can also use a PC with the PowerMon Manager software. We also offer a library for accessing the PowerMon devices so you can write your own custom software for PCs and Raspberry Pi boards. Check out the PowerMon Software page.
Try before you buy.
Install the PowerMonX app from the Apple App Store or Google Play. Using your mobile device, tap the link below — it will open directly in the PowerMonX app.
You’ll connect to a live PowerMon-W demo device and explore real battery data in real time. PowerMon-E is virtually identical to PowerMon-W except is has Ethernet connectivity instead of Wi-Fi.
Go ahead and test before you buy. Install the PowerMonX app from the Apple / Google app stores. Using your mobile device, tap on the link below. It should open with the PowerMonX app. This is a demo device.
Please read the Product Use Disclaimer & Warranty Policy at the bottom of this page before ordering.
What's In the Box?
- PowerMon-E Ethernet Battery Monitor
- Wiring harness with pre-crimped terminals

Use PowerMon In

With dual 64V inputs and support for an external current shunt, PowerMon-E delivers complete, remote battery analytics — including real-time voltage, current, power, lifetime energy tracking, amp-hour counting, state-of-charge calculation, accurate runtime prediction, and temperature.

Access your PowerMon-E from anywhere. With Ethernet connectivity, you can monitor your battery system in real time using your smartphone or tablet — whether you're at home, at work, or across the globe.
Installed in a remote location without Internet? PowerMon-E still works. You can access all monitoring features directly, via the local network.

PowerMon-E can be connected to any external shunt rated up to 1000A or more, enabling monitoring of high-current systems. For maximum installation flexibility, the external shunt can be installed on either the positive or negative side of the battery system.

Don't leave your expensive batteries unprotected!
Paired with a relay, PowerMon-E can serve various functions, including acting as a low-voltage disconnect, high-voltage disconnect, over-current disconnect, low-temperature disconnect, high-temperature disconnect, or generator controller. And by the way, we also offer timer functionality.

PowerMon-E features built-in data logging with up to three years of onboard storage. Unlike many competing products that store history inside the mobile app, PowerMon-E records data directly inside the device itself.
This means you do not need to keep a phone or tablet permanently connected to the monitor.
Whenever you connect via the mobile app, stored logs are automatically downloaded from the device.
PowerMon-E records:
- Voltage
- Current
- Power
- Temperature
- State-of-Charge (SOC)
The logging interval is user-configurable, from once per second to once per minute, allowing you to balance resolution and storage duration.

Enable the generator control feature and PowerMon-E can automatically start your generator when battery voltage or state-of-charge (SOC) drops below a user-defined threshold.
Maintain reliable power without constant supervision — PowerMon-E ensures your batteries are protected and recharged when needed.

PowerMon-E operates on under 30mA of current. This is comparable to a typical battery self-discharge rate.
With dual 64V inputs and support for an external current shunt, PowerMon-E delivers complete, remote battery analytics — including real-time voltage, current, power, lifetime energy tracking, amp-hour counting, state-of-charge calculation, accurate runtime prediction, and temperature.
Access your PowerMon-E from anywhere. With Ethernet connectivity, you can monitor your battery system in real time using your smartphone or tablet — whether you're at home, at work, or across the globe.
Installed in a remote location without Internet? PowerMon-E still works. You can access all monitoring features directly, via the local network.
PowerMon-E can be connected to any external shunt rated up to 1000A or more, enabling monitoring of high-current systems. For maximum installation flexibility, the external shunt can be installed on either the positive or negative side of the battery system.
Don't leave your expensive batteries unprotected!
Paired with a relay, PowerMon-E can serve various functions, including acting as a low-voltage disconnect, high-voltage disconnect, over-current disconnect, low-temperature disconnect, high-temperature disconnect, or generator controller. And by the way, we also offer timer functionality.
PowerMon-E features built-in data logging with up to three years of onboard storage. Unlike many competing products that store history inside the mobile app, PowerMon-E records data directly inside the device itself.
This means you do not need to keep a phone or tablet permanently connected to the monitor.
Whenever you connect via the mobile app, stored logs are automatically downloaded from the device.
PowerMon-E records:
- Voltage
- Current
- Power
- Temperature
- State-of-Charge (SOC)
The logging interval is user-configurable, from once per second to once per minute, allowing you to balance resolution and storage duration.
Enable the generator control feature and PowerMon-E can automatically start your generator when battery voltage or state-of-charge (SOC) drops below a user-defined threshold.
Maintain reliable power without constant supervision — PowerMon-E ensures your batteries are protected and recharged when needed.
PowerMon-E operates on under 30mA of current. This is comparable to a typical battery self-discharge rate.







Why You Need a PowerMon
In case you were wondering
PowerMon Battery Monitor Comparison


Bluetooth Low Energy
Bluetooth Low Energy
Wi-Fi
Two
One
Two
64V
32V
64V
Max. 60A
Max. 500A
No
Any (optional)
No
Any
Either positive or negative side
Positive side only
Either positive or negative side
Involved (more wiring needed)
Easy (minimal wiring required)
Involved (more wiring needed)
High (device is encapsulated in epoxy)
Low (install inside protection box)
High (device is encapsulated in epoxy)
Frequently Asked Questions
Here are some questions our customers ask us the most.
I see two apps: PowerMon and PowerMonX. Which one should I use?
PowerMonX is our latest app, offering enhanced features compared to the older PowerMon app. All new devices now come equipped with PowerMonX. If you own an older device, you can update to PowerMonX, but please note that it requires a device with a hardware revision of at least 2.3 (2.30). All devices sold after mid-2019 are compatible with PowerMonX.
How can I find the hardware ID of my device?
Connect to your device.
For the older PowerMon app go to the About page.
For the newer PowerMonX app go to the Device Information page.
What kind of relay can I use?
Any relay that matches the voltage of your system, with a coil current rating of less than 1A can be used.
It's highly recommended to use a solid-state relay like the TL-SSR12100DCU. However, if you prefer a mechanical relay, it will work.
What about SSRs (Solid State Relays)?
Yes, you can use an SSR. One of its advantages, when compared to a mechanical relay, is that it requires much lower current to hold in the ON state, typically around 20mA, whereas mechanical relays may require up to 1A or higher. This lower current requirement is especially beneficial in boats and RVs where power resources are limited. Additionally, SSRs have the advantage of not wearing out their contacts, producing no sparking, and operating quietly.
The TL-SSR12100DCU SSR was specifically designed by Thornwave Labs for use in RVs, boats, and other vehicles equipped with a 12V electrical system. We also have SSRs for higher voltages.
Should I install the shunt on the positive or the negative side of the battery?
PowerMon allows you to install the shunt on either side, or even in between batteries that are connected in series. It doesn't matter as long as the maximum voltage on the shunt is kept within -0.6V to +64V relative to the battery negative.
We advise installing it on the positive side because this way you will not disturb the ground connection.


