PowerMon-5S - 500A Bluetooth LE Advanced Battery Monitor / DC Power Meter with data logging

Designed and assembled in USA.

We developed the PowerMon-5S device to provide an affordable, high-tech solution for monitoring electrical systems. Whether you're in an RV, camper, or boat, utilizing solar systems, or managing off-grid setups, PowerMon-5S is designed to meet your battery monitoring needs. Remotely monitoring DC circuit parameters has never been easier!

We also have PC software and a library for accessing the PowerMon devices so you can write your own custom software. Check out the PowerMon Software.

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 PowerMon-W demo device. It's the same thing as the Bluetooth PowerMon. It accepts only 16 simultaneous connections so please don't leave your phone connected to it. Other people want to test it too.

https://applinks.thornwave.com?n=DemoUnit&s=36129e86da98dda9&h=40&c=HzotUykUSvP/Ox0xdUpYVw%3D%3D&k=//////////////////////////////////////////8%3D

Please read the Product Use Disclaimer & Warranty Policy at the bottom of this page before ordering.

  • Operates at up to 32V, allowing it to work in 12V and 24V systems
  • Measures up to 500A using the integrated high-precision 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.
  • Bluetooth LE, fully configurable
  • Data logging that can store up to 3 years of data history
Sale price$99.99

Use PowerMon In

RVs

Probably our biggest market. Any RV has at least one battery. You should know how much power you have left!

Boats

Kinda like an RV but for the aquatic specimens. They have big batteries, solar panels, ACs and water makers.

Smart Home

Do you have solar? Maybe you should. You should also use a PowerMon to check how much power you're generating.

Solar Energy

From the smallest solar system (20W) to the largest... PowerMon can find it's way in your system.

Automation

Control lights, water pumps, generators, or irrigation using PowerMon's built-in timers.

01

PowerMon is a battery monitor

It can measure voltage up to 65V and current up to 60A using an integrated shunt. It then calculates power (W), energy (Wh), charge (Ah), battery state-of-charge (SOC %), and estimated time left until the battery is fully discharged.

02

And it's Bluetooth

PowerMon is equipped with a Bluetooth LE (Low Energy) radio. You can use your cellphone or tablet to connect to it and check what your battery is doing. Install PowerMon inside a battery box or equipment bay and forget about it.

03

It has an integrated 500A shunt

PowerMon can monitor currents up to 500A using the integrated shunt. It should be installed on the positive side of the battery to avoid any interference with the ground wiring.

04

And it can drive an external relay

The capability of driving a relay opens up a lot of possibilities. You can use either a mechanical relay or a solid-state relay for various applications, such as a remote ON/OFF switch, battery protection, or even starting a generator.

05

Many protection features

Don't leave your expensive batteries unprotected!

Paired with a relay, PowerMon 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.

06

Logs the data for up to 3 years

Record what your battery is doing! PowerMon can log data for up to 3 years in internal memory, unlike other similar products on the market that store it inside the mobile app. This means you don't need to have a mobile device permanently connected to the battery monitor. Whenever you connect to PowerMon, the mobile app will download the data logs from the device. PowerMon records voltage, current, power, temperature, and state-of-charge, and you can adjust the recording frequency from once a second to once a minute.

07

And can even start your generator

Enable the generator control feature, and PowerMon can start your generator when the voltage or state-of-charge drops below a specified threshold.

08

Very Low Power

PowerMon does it all while sipping on only 3mA. The battery self discharge is higher than what PowerMon needs to function.

09

But if Bluetooth only is not enough

We have a screen to go with it too. PowerMon-D4 is a 4.3" color touchscreen that connects to the PowerMon via Bluetooth. It also has WiFi, and we plan to add support for cloud connectivity in the future.

01

PowerMon is a battery monitor

It can measure voltage up to 65V and current up to 60A using an integrated shunt. It then calculates power (W), energy (Wh), charge (Ah), battery state-of-charge (SOC %), and estimated time left until the battery is fully discharged.

02

And it's Bluetooth

PowerMon is equipped with a Bluetooth LE (Low Energy) radio. You can use your cellphone or tablet to connect to it and check what your battery is doing. Install PowerMon inside a battery box or equipment bay and forget about it.

03

It has an integrated 500A shunt

PowerMon can monitor currents up to 500A using the integrated shunt. It should be installed on the positive side of the battery to avoid any interference with the ground wiring.

04

And it can drive an external relay

The capability of driving a relay opens up a lot of possibilities. You can use either a mechanical relay or a solid-state relay for various applications, such as a remote ON/OFF switch, battery protection, or even starting a generator.

05

Many protection features

Don't leave your expensive batteries unprotected!

Paired with a relay, PowerMon 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.

06

Logs the data for up to 3 years

Record what your battery is doing! PowerMon can log data for up to 3 years in internal memory, unlike other similar products on the market that store it inside the mobile app. This means you don't need to have a mobile device permanently connected to the battery monitor. Whenever you connect to PowerMon, the mobile app will download the data logs from the device. PowerMon records voltage, current, power, temperature, and state-of-charge, and you can adjust the recording frequency from once a second to once a minute.

07

And can even start your generator

Enable the generator control feature, and PowerMon can start your generator when the voltage or state-of-charge drops below a specified threshold.

08

Very Low Power

PowerMon does it all while sipping on only 3mA. The battery self discharge is higher than what PowerMon needs to function.

09

But if Bluetooth only is not enough

We have a screen to go with it too. PowerMon-D4 is a 4.3" color touchscreen that connects to the PowerMon via Bluetooth. It also has WiFi, and we plan to add support for cloud connectivity in the future.

Why You Need a PowerMon

PowerMon comparison

In case you were wondering.

Connectivity

Bluetooth LE

Bluetooth LE

WiFi

Number of Voltage Inputs

Two

One

Two

Maximum Voltage

65V

32V

72V

Integrated Current Shunt

Max. 60A

Max. 500A

No

External Current Shunt

Any (optional)

No

Any

Battery Side

Either positive or negative side

Positive side only

Either positive or negative side

Installation Difficulty

Involved (more wiring needed)

Easy (minimal wiring required)

Involved (more wiring needed)

Protection From the Environment

High (device is enclosed in epoxy)

Low (install inside protection box)

High (device is enclosed in epoxy)

Frequently Asked Questions

Here are some questions our customers ask us the most.

Customer Reviews

Based on 20 reviews
85%
(17)
10%
(2)
0%
(0)
5%
(1)
0%
(0)
J
Jon A.
Best shunt!

I have bought several shunts, and none of them come close to the PowerMon 5-S. Accuracy, calibration, connectivity, and most of all, data logging.

Easy to install, configure and super easy to use in combination with the PowerMon-D4 display. I love this set up and it is my preferred and recommended way to monitor RV solar and battery banks. 5 stars from me.

t
thomas s.
PowerMon 500

I have your PowerMon 500. It’s worth every penny for helping to manage my solar system. I have a cabin that is still linked to the grid as there is not enough consistent sun in Dec-Jan. The data recording and downloading make it easy to estimate my capacity based on the weather forecast when I am gone during the week. It takes a season or two to understand your loads but it works great.

T
Thomas T.
Works with RV Whisper

Really like that this works with RV Whisper. I have one application monitoring power and other devices. Have been very happy with the device.

E
Ed T.
Very good and capable battery monitor

I have been very pleased with my Thornwave PowerMon 5S battery monitor. I especially like the way the data is stored on the device, even when the app is not connected. I use the data log feature to monitor changes over time, and I’ve quickly come to trust this device, more than all of the other battery and voltage monitors that I have installed. I look forward to the remote monitoring capability, but even without that capability today, I think it is still the best battery monitor on the market.

C
Christopher S.
Best there is

I’ve bought about a dozen of these for various clients and theirs is nothing better. No competitor makes a better product with better features. Best money you’ll ever spend!!!