Eos is a car that competes in the Cruiser class. It was the only Cruiser class vehicle that qualified at American Solar Challenge 2016.

Battery

Minnesota has a relatively-large single pack of 18650 batteries, running at 160V. This results in a pack that weighs around 60kg (so approximately 1300 cells). As a result, their design for battery mounting accounts for sliding the pack in and out, with the pack being accessible at about torso height. This makes the pack more manageable to move both out and access, when working on the electrical systems.

Their pack is configured in an S-shape

Battery Management System

Voltage & Temperature Sense

What's interesting and different about Minnesota's battery pack is the fact that they have a PCB mounted in the middle of each row in the pack (show picture with where the PCBs are located) that their inputs connect into

This PCB essentially just has a connector mounted on it, which plug into the Analog Front-End devices to provide the inputs for voltage and temperature sensing. This makes wiring a lot more manageable, as each line from the battery goes into the PCB, and then a bundle comes out of each PCB to the BMS board.

Battery Modules

They manufactured the ABS plastic brackets themselves, by milling them out using the CNC machine in the University of Minnesota mechanical engineering student shop. This involved using featureCAM to create tool paths and G-code to run the machine.

They created a jig so that the blanks could be bolted to a plate and then milled out, four at a time. This process took the team over 2 weeks to complete.

They spot-welded their battery pack to nickel strips through the bracket, using a spot-welder they built for their previous car (Daedalus).

Diamond Metal Products sponsored the laser-cut nickel pieces.