ER21

The change towards electric mobility is not only visibible on the streets around us, also the Formula Student competition is changing. In 2019, Formula Student Germany announced that the combustion class will be phased out over the coming years. We in LiU Formula Student did some early studies to investigate the change towards EV, but never fully comitted to an electric car. Until 2020.

With the onset of a global pandemic in March 2020, all physical work on the ER20 car was stopped and the university went into distance mode. The newly elected ER21 management, together with the ER20 management, decided to use the time at home to start developing ER21. And with half a year of extra time, we comitted to go electric.

The main goal of ER21 was to develop competencies to design and build an electric race car. The car should be as simple as possible, therefore a single motor in the rear and a convential drive train with differential was chosen. The suspension was only slightly modified in comparison to ER20 and the aerodynamics package was further improved. Preassembled modules were used for the battery and an own battery management system was developed.

Both the change to EV, as well as the COVID-19 pandemic challenged us throughout the year. While we were able to finish the car mechanically, the integration of all electric circuits gave us serious headaches and ultimately ended in us not being able to finish the car in time for competition. Still, LiU Formula Student took a huge leap towards electrifying our organisation and laid the foundation for future success.

80

[kW] – POWER

245

[kg] – MASS

8.0

[kWh] – CAPACITY

PICTURES

FEATURES

Motor

Emrax 228 HV LC, 109kW peak (limited to 80kW)

Inverter

UniTek BAMOCAR-PG-D3-700/400

Battery Cells

720 x Sony VTC6 18650 cells
(preassembled as Energus Li1x5pVTC6T)

Battery Configuration and Voltage

144s5p - 600V

Battery Capacity

8.0 kWh

Differential

Drexler FS2016 LSD

Chassis

Tubular steel spaceframe

Body

Carbon fibre

Aero

Front and rear wing

Suspension Front

Double unequal length A-arms, pull-rod, horizontally oriented Öhlins TTX25 dampers

Suspension Rear

Double unequal length A-arms, push-rod, vertically oriented Öhlins TTX25 dampers

Wheelbase

1535 mm

Track Width [F/R]

1200 / 1180 mm

Wheel

13x7.0" OZ magnesium rims

Tires

Goodyear 20.0 x 7.0-13"

Weight

245 kg

ROLLOUT