As of 2023-08-12, revision 1 of the aux battery is no longer sufficient to power the car over a race day of 9 hours due to updated driver fan loads and updated contactor loads.
Supplemental/Aux Battery - Revision 1 Notes
The purpose of this confluence page is so that electrical members may review my calculations.
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Persistent Loads
These loads will be operating over the course of the entire race day. As of right now, the contactor power draw and horn power draw is based off the Systems Integration Meetings - Electrical - Confluence (atlassian.net) page point estimates, which may not be current?
Emergency Loads
These loads will be operating only in the case of a BPS emergency causing the main battery pack to be disconnected. In the case of a BPS fault, as of systems integration meeting 2023/07/05, the LV systems will be powered solely off of the aux battery. The LV systems must be able to hold up until car finds a safe place to park. These loads were based off of the WIP LV power budget as of 2023/08/12. We assume that the horn must run for 5 minutes straight, and the rest of the LV systems must run for 5 additional minutes (?) – MUST CONFIRM.
Load | Description | Energy Demand [Wh] | ||
|---|---|---|---|---|
Persistent Loads: | ||||
Telemetry – Router | Assume 2.5W for a raspberry pi, 9 hr race day | 22.5 | ||
Driver Fans | 2 Noctua NF-F12 iPPC 3000, overvolted to 15V, 5.1W x 2 max tested power draw for 9 hrs
| 91.8 | ||
Contactors (BPS Switch) | 3.5W, 9 hr race day | 31.5 | ||
Total Persistent Loads: | 145.8 | |||
Emergency Loads | ||||
Horn | Horn must be able to be run for 5 minutes in an emergency as per regs | 0.583 | ||
All LV systems – Typical | 91.0 W, 5 minutes | 7.58 | ||
Total Emergency Loads | 8.16300 | |||
Total | 153.96 |
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