Bluetooth Battery Monitor / DC Power Meter

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$119.00 $109.00Add to cart

  • PowerMon is a Bluetooth hi-tech device that can be used to monitor the state of charge of any battery and power flow in any electrical system. On top of the monitoring functions, PowerMon can act as a power controller, allowing for low voltage disconnect, high voltage disconnect, over-current disconnect, battery isolator, remote ON/OFF switch, timer switch, generator control, and solar system automation. With Bluetooth LE (Smart) connectivity there is no need for drilling and extra wiring in existing or new applications (RVs, boats, solar systems). Small form factor and ease of installation make PowerMon ideal for quickly adding smarts to any existing electrical system. Remotely monitoring DC circuit parameters has never been easier!

    Voltage, current, power, energy, battery state of charge, and temperature are all measured and displayed in real-time using Thornwave Labs’ mobile application, PowerMon, which is offered for free on Google Play and Apple App Store. The device supports multiple configurations and measurement ranges that can be set up using the app, allowing it to accommodate a variety of circuits. Control of a mechanical or solid-state relay allows it to be used for low voltage disconnect, high voltage disconnect, over-current disconnect, a battery isolator for multiple battery systems, remote power control, or timers. This wireless, multi-function tool is truly a Swiss-army knife for DC electrical systems.

    The device measures two voltages up to 75V with better than 0.5% accuracy. It contains an internal shunt making it able to measure current up to 60A without using any external parts.  The current measurement can be calibrated to an accuracy better than 1%. If higher current has to be measured (as high as 10,000A), an external shunt can be added. Current shunts are readily available and can be customized for the specific current measurement range required. PowerMon supports a wide range of current shunts.

    • Remotely monitor two DC voltages, current, power, energy (Wh), battery charge, (Ah) and temperature
    • Measure voltage up to 75V and current up to 60A using the internal current shunt
    • Sense up to 160mV of voltage drop across an external current shunt, allowing up to 10,000A of current to be measured
    • Monitor battery state of charge (in %) and remaining battery runtime
    • Control a power relay or SSR (Solid State Relay)
    • Low / high voltage disconnect, over-current disconnect or disconnect based on the fuel gauge (battery state of charge)
    • Battery isolator for multiple battery systems
    • Remote ON/OFF switch and timer functions
    • Lithium iron phosphate charge manager
    • Password lock function
    • Low (8mA) self consumption
    • Easily configurable
    • 3.0″ x 1.55″ x 0.75″ (76mm x 39mm x 19mm) including the mounting flanges
    • Solidly built
    • Weatherproof
  • The PowerMon app is available for both Android and iOS and can be installed for free from Google Play Store and Apple App Store.

    Android Screenshot
  • Support Email

    Or call 1-888-399-WAVE

Common Applications





Smart Home

Smart Home

Solar Energy

Solar Energy



App Screenshots

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  • This is a great little device. The Bluetooth works better than I expected as I can use it over 80 feet away in my house through multiple walls. It can do so many things for the price, but it would be worth it just for the power meter.

    Jason Lee
  • People, this thing now with the SOC and battery remaining time is awesome. This thing does everything the really expensive ones do. I bought one, tried it out, had a couple of issues, contacted Raz and he was very quick to reply and set me up. It really is very easy to set up and the app is great. Anyone with an off grid solar system (cabin, boat, RV etc.) should get one of these. You will not be sorry.

    Scott Tracy
  • I hooked up following your (excellent) instructions and it worked. It only took me a couple of minutes.

    You need to understand that I’m retired and used to work in theoretical mathematics and computer science (artificial neural networks, Bayesian statistics & linear programming). That is to say I usually blow up or otherwise destroy these kind of projects.

    China Clipper
  • High quality product – easy to set up, impressed by how compact it is while it feels pretty strong and durable. The Bluetooth connectivity is as great and just what I’ve been looking for. I had a small question and support got back to me right away.

  • I recently bought this product, and I can say that I am impressed by the size of the device, its measurement precision and how easy it is to use it.


Product Demo


  • Any shunt that develops a maximum voltage drop of 80mV (if used to sense current in both directions) or 160mV (if used to sense current in one direction only) and supports the maximum current you want to measure would work. Here are a few examples: 500A/50mV, 500A/75mV300A/75mV200A/75mV

  • Make sure the location services are enabled. Also make sure that the app has access to Location Services (under Application Manager you can control what services is any application allowed to use). Also, if you just upgraded to Android 8 (Oreo), restart your phone. 

  • Android 4.4

  • Any relay with a coil voltage of 12V and current less than 0.5A works. 

    It is better to use a solid state relay (TL-SSR12100DCU) but if you insist on a mechanical one, here are some examples of automotive relays: 40A relay200A relay

    Also, note that a relay is only required if you are planning to use the low voltage disconnect or any auto-disconnect feature or the remote ON/OFF feature. For an RV / boat installation it is recommended to use a relay. This will allow you to turn the power off entirely when in storage (to avoid parasite loads draining the battery). The low voltage disconnect will protect the battery against over-discharge which can damage it. 

  • Yes, you can use an SSR.

    One of the advantages compared to a mechanical relay is that they require a much lower current to hold in the ON state (about 20mA compared with up to 0.5A for mechanical relays). This makes a big difference in boats and RVs where power is limited. Also the contacts don’t wear out, there is no sparking and it is quiet. 

    The TL-SSR12100DCU SSR was built by Thornwave Labs specifically for RVs, boats and other vehicles with a 12 Volts electric system.

  • PowerMon allows you you 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 -4V to +65V. 

    We advice to install it on the positive side because this way you will not disturb the ground connection. 

  • No. PowerMon cannot log any data. Stay tuned though for future products!