Purpose: Validate that our manufacturing procedure yields a module that can function in all realistic discharge scenarios Tests: Module Resistance 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 5258.4A2A Test: Draw 52.4A 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.  |