Arduino for controlling the cooling system

The cooling system of my electric Volvo Amazon wagon will have three circuits.

  1. Motor = 70 to 90 degrees
  2. Controller = 30 to 40 degrees
  3. Batteries = ideal temperature 25 degrees

In every cooling loop, a Pierburg CWA-50 electric pump will be used.

Pierburg CWA50 met connector

It can pump up until 30 liters per minute but does draw almost 7 Amps (80W) while doing so. Times three is quite some energy consumption. It can be controlled by PWM (pulse width modulation). This allows you to have it run slower (and thus use less energy) in case less cooling capacity is required. Initially I wanted to use a Siemens Logo PLC but after some discussion on the Siemens forum it turned out to be not fast enough.


Arduino is an open source microcontroller and available in many variants. After exchanging some messages in the Arduino forum and help from Erik (thanks!) it turned out an Arduino should be able to accomplish the tasks. In the end I want the following:

  • Control the speed of the coolant pumps based on the temperature in a circuit
  • Be able to mix the circuit of the controller and batteries to use the waste heat from the controller to warm up the batteries to 25 degrees
  • Be able to disconnect the radiator in the cooling circuit of the batteries when the water is being heated (by electricity)
  • Being able to switch on the heating of the battery circuit remotely
  • Being able to switch on two 150W fans
  • Be able to switch on a fan mounted in front of the battery circuit radiator in case additional cooling is required

I hardy have any experience in programming in C/C++ or connecting Arduino hardware so I am learning. If there is someone willing to help to build/realise the above, that would be very welcome!

Arduino Mega 2560

I have chosen to use the Arduino Mega 2560 board since it had a lot of in/outs and multiple timers (relevant because probably the standard PWM frequency is too high).

Arduino Mega 2560 board

Learn & experimenter

One learns most by doing, so I bought a book and some basic components.

Arduino startset toebehoren

Furthermore I already bought some additional hardware like the Adafruit FONA 808. This is some kind of GPRS modem for Arduino which hopefully allows me to easily control the Arduino remotely using Blynk.

Arduino ADAfruit Fona 808

Next I created my first project, a led that can be switched on and off by pressing a button.

Arduino eerste schakeling

A lot of fun! To be continued.

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OldVolvo is a classic Volvo hobby blog by Lars Rengersen.

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