Bring your product to market on time and within budget – join the Eurocircuits Community

LiU-Formula-Student-Blog-Banner

PCB Solutions: Battery Management System for Electric Vehicle

LiU-Formula-Student-Car-Web

Who are we?

Everyone in the LiU Formula Student Team are students studying at Linköping University in Sweden. Most of our members study mechanical or electrical engineering and we do this project separate from our standard courses. The project is sponsored both by Linköping University and our company sponsors. The entire project is planned, directed and managed by us students from start to finish. The entire group consists of about 60 students in total.

What is Formula Student?

Formula student is a competition between universities worldwide designed in the spirit of the Formula 1 racing sport. Each university team design and build their own vehicle and race it against other teams. There are many different competitions worldwide that you can qualify to and compete in.

Why build an electric vehicle?

At present, many automobile manufacturers are shifting towards electric cars as batteries become more energy efficient. We in the LiU Formula Student Team want our members to stay ahead of the curve, so for the 2021 competition we decided it was time to build an electric car for the first time.

What is a ‘Battery Management System’ (BMS)?

The Battery Management System (also called BMS) is a system that monitors the batteries in the car and ensures that they charge and discharge properly. This system is crucial for the mileage and overall safety of the car. Creating this system has been one of the key challenges in the LiU Formula project for 2021.

Starting from scratch

When starting with the BMS we were a group of 4 people in the powertrain team. None of us had prior experience with designing a BMS before.

Our first task was to establish an outline of the BMS. Should we buy one or build a BMS ourselves? How complex should we allow the BMS to be? How will the BMS fit together with other systems?

Eventually we settled on a master-slave design where a single master processor controls a set of 12 daisy-chained sensor slave boards. Each slave board measures the temperature and voltage of 12 lithium-ion cells and is no longer than a medium sized ruler.

The powertrain team has also been responsible for making two PCBs outside of the battery container. These were the Vehicle Control Unit (VCU) and the Traction System Active Light controller (TSAL). The VCU is a board that works similar to how the throttle works on a fuel driven car, i.e., it restricts motor power depending on the input of the driver.

The TSAL controller has the duty of informing the driver if our traction system is in a safe state using a standard LED-light.

In total, we have bought over 20 PCBs from Eurocircuits; we are happy and satisfied with the quality of the PCBs. Shipments were fast which was very appreciated during the prototyping phase.

LiU-Version-1-Master-PCB-Web

Version 1 of the Master PCB

LiU-Version-2-Master-PCB-Web

Version 2 of the Master PCB

LiU Formula Student Logo

For more information, please visit our website.

Ludvig Rasmusson
BMS Design Engineer
LiU Formula Student 20/21

Be the first to read all about our news and information. Follow us on