This document is intended to be an extended version of the testing plan from the PVDR (preliminary vehicle design report).
Prototype Module Testing:
Purpose: Validate that our manufacturing procedure yields a module that can function in all realistic discharge scenarios
Tests:
Module Resistance
See Single Cell Testing - Data Processing Guide for a more detailed overview of the intricacies of DCR measurements
Use Fluke multimeter to check resistance on terminals of battery module. (Don’t use other brands as they may not be as accurate)
Test: Measure module internal resistance. Follow this tutorial: https://www.youtube.com/watch?v=av38iBxcOgQ
The cells in 4S8P configuration alone, based off of the datasheet internal resistance (IR) should have an IR of 0.015ohms (0.012 - 0.018ohm considering variation)
Information gained: The measured internal resistance should tell use how much resistance is introduced from out spotwelds and busbars (indication of how good our spotwelds are)
Nominal Current Test
Based on energy budget calculations, we can afford to have a nominal current of 4.54A Energy Budget and Average Current Draw Calculations
Test: Discharge for 8h at 4.54A to simulate a full race day
Information gained: The temperature rise from normal operations. (if this is too high then we may not want to use epoxy on cells)
High Current Test
Our modules are rated for a max discharge of 58.2A
Test: Draw 58.2A from module for 10 min
Information gained: Temperature rise from max discharge, visual observations of module in case anything unexpected occurs
Test set-up:
Attach module to module connections with M4 bolts, Belville disc springs, and regular washers in this stack up ( Nut - Washer - Busbar - Contact Grease - Busbar - Washer - Springs - Bolt ). Torque the M4 connections to 2.4 N*m.
This way we can see from the tests how good the connections between modules are (IR introduced) and if the module-module connections introduce any issues.
