Wattmon - Intelligent Remote Monitoring and Control

Wattmon helps you log data, monitor and control your devices over the Internet


Access your data over the Internet using any browser or smart phone


Log data and control your devices with automated rules - no programming required!


View intuitive graphs to understand and troubleshoot your system easily

Where can Wattmon be used?

Keeps track of remaining capacity and battery health with options to automatically control charging.
Interface with Inverters and Power meters to log AC energy - monitor your grid tie solar inverter production remotely.
Control devices around your home or company automatically. Meet the Internet of Things!
Remotely monitor your AC & DC solar pumps including water flow rate and power
Monitor solar energy production and DC energy generated
Monitor wind speed or energy generation from your turbine
Measure temperature, pressure, humidity, irradiation, wind speed, rainfall and more
Monitor telecom tower batteries and automate charging

Features & Benefits

Highly Versatile
Lets you customise device to your exact needs with intuitive interfaces
Easy To Use
Allows non-programmers to configure and automate things
Accessible from your phone, tablet and pc through our proxy server from anywhere
Industry Compliant
Integrate new and existing devices easily using Modbus RTU & TCP
Local Storage
Securely store your data locally, control who can see it
Cloud Ready
Upload data to your own server or use our advanced cloud portal
Write your own scripts in a built-in editor using uPHP to extend functionality


I don’t see anymore how it is possible to manage a solar system without the full monitoring and control provided by Wattmon, it is a small investment that makes the big one - of the solar system - finally 100% worth its value.
Didier / Auroville / India
I am very happy to be using a Wattmon; it is very practical and controls the charging, from the mains, of my battery bank during the night time, whenever the battery charge level falls below a certain level and stops the charging when it reaches another level. All these parameters are programmable and can even be managed remotely. As a result I believe my battery will have a longer and better life than otherwise. The Wattmon is being continuously improved and upgraded...it's a very necessary accessory to your solar power system.
Angad / Auroville / India
We have been impressed by the flexibility of the Wattmon, its simple programmability enabled us to use it for a complicated application that would otherwise have required designing our own device.
Mitra / Lumeter Networks / USA

How Can Wattmon Help You?

Versatile Solutions

Monitoring Hardware
Devices that let you get to your data remotely with minimal hassle
Cloud Portal
Find out how our cloud based portal can help you
Understand the Wattmon system quickly

Battery Monitoring

Wattmon has built-in features for battery monitoring, and with a few configuration settings you can keep track of a battery bank with voltages ranging from 12V DC to over 300V DC. For low voltages below 60V DC (a 48V battery bank) Wattmon can be directly connected to the batteries via the cable provided, and voltages will be measured from the same cable. For higher voltages an additional power adapter is required.

How does it work?

There are various ways of determining the remaining capacity in a battery. One of these ways is called Coulomb Counting. Another uses voltage to determine the remaining energy. A third method will actually check the specific gravity of the battery liquid to determine the state of charge.

Wattmon monitors inbound and outbound current from the battery bank and uses the Coulomb Counting method. Current flowing through the sensors is read once a second and accumulated in registers.  By configuring the total capacity of the battery, an accurate view of remaining energy is then calculated by subtracting and adding from this value. 

For example: 

A 100 Ah (Ampere hour) battery will be (theoretically) able to supply 10 Amperes for 10 hours (10 A/h * 10h = 100 Ah).  If you take out 10 A for 1 hour, Wattmon will show your battery State of Charge (SoC) as 90%.  If you then charge the battery at 10 Amps for 30 minutes, the battery will show 95% full (90 Ah + 5 Ah).

The Algorithm

Wattmon lets you set the various parameters in the Control Panel. Wattmon will reset the battery status to full when the battery voltage is higher than the 'full voltage' threshold (adjustable) and the current drops below a specific value (adjustable) for a set period of minutes (adjustable). This flexible set of options ensures that most requirements can be easily met.

Different battery chemistries have different efficiencies. You can enter the charge efficiency if you desire to get even more accurate results. If you are using a lead acid chemistry, you can also enter the Peukert constant of your battery bank to get an accurate discharge profile for higher currents.
This method has in our experimental setups proven to be quite accurate. It is definitely more than sufficient to get a good overview of remaining energy.
The device will, based on the remaining energy and the average load over the last few minutes calculate the run time through a web interface from your PC or mobile.


There are many devices which claim to have an accuracy of below 1%. We claim no such thing! It is accurate when it comes to estimating the remaining capacity, however there are cases when it can be off by up to 5 or 10%. Lead acid chemistry is in general difficult to measure accurately. There are temperature differences and many other factors that will affect the state of charge of a battery.

The Hardware

In order to monitor a battery bank, you will require a WattmonPRO and a current sensor module.  Depending on the current you need, this could be the C252 (25A), C502 (50A) or C752 (75A) or the C100s (100A) modules. The two sections below explain how to connect up the system to monitor different types of setup.  Please note that if only one channel is required (for example when only using an inverter and no solar) the left channel of the current sensor module can be ignored.

Monitoring Battery Banks of Upto 48V DC

The following diagram shows the components required to monitor battery banks of up to 48V DC.

Diagram: Monitoring battery bank setups of up to 48V DC

Monitoring Battery Banks of Upto 330V DC

The following diagram shows the components required to monitor battery banks of up to 300V DC.  This requires an additional AC to DC or DC/DC power adapter to power the WattmonPRO device.

Diagram: Monitoring high voltage battery banks (up to 330V)

The battery ground needs to be tied to the power adapter ground. 

Tip: Using a switch mode power supply, you can connect the power adapter directly to the high voltage battery terminals.

View WattmonPRO Details

View C752 Dual Current Sensor Details


Wattmon Is Going to Intersolar 2017

We are going to be at Intersolar Munich (May 31-June 2) and look forward to meeting you all there at stall B3.472!

We will be showcasing our two existing products, the WattmonPRO and WattmonMINI and launching our newest product, the WattmonMEGA.

Cluster Management

The new Sync package in Wattmon allows multiple global variables to be synced between different devices in a virtual cluster. This opens up endless possibilities for distributed control based on data spanning large geographic areas. Devices can be configured to read or write multiple variables.

Zero Feed In

India does not allow grid feed in certain areas, and any energy fed into the grid is charged to the customer. Using WattmonPRO with the Sync package, it is possible to monitor the main incomer power meter with one Wattmon and transmit this data to the cloud and sync it to various rooftop grid tie setups across the campus. At user-definable intervals each Wattmon will receive the total energy being imported/exported and decide on the correct power limit for the inverters, either throttling or increasing production to ensure that all generated energy only goes to the campus and does not get fed back to the grid.

Global Settings

Another application could be to enforce global setting changes across multiple locations in situations where a large number of devices are deployed. For example, a street light controller’s switching time may need to be adjusted remotely and it would be impractical to connect to each controller manually.

How it works

Wattmon devices poll the sync.wattmon.com server periodically for updates to read variables using a unique cluster read key. It can read all variables or a selection. These variables are then updated into the Wattmon’s $_GLOBALS array making it accessible to the scripting language and actions. Additionally, a global sync array is created which also keeps track of the last update to the variable so the device can determine whether the data is current or not.

For write variable, the Sync package takes the values of the global variables and sends them to the server at fixed intervals using a unique write key.

The MAC address of each device is logged on the server, making it easy to debug the system.

The Sync API will be available in the 2.15 release of WattmonOS.