UTA Racing 2023 Accumulator Pre-Tech Accumulator Inspection
This video is a pre-competition inspection of our Accumulator. It follows a technical inspection form, found at:
www.fsaeonline.com/cdsweb/gen/DownloadDocument.aspx?DocumentID=9d9f0ac2-f63a-43e6-bd16-746e13d24365
The battery pack is a 504V max pack, made from 600 NMC 18650 Cells, with a 6.8kWh capacity. The complete package weighs 119.3 pounds.
To other FSAE teams:
You are welcome to use this video for inspiration for your own designs. I would not build another pack this way. The 120 busbars are difficult and time-intensive to install. Maintence on the segments is also very difficult. If you used this video for inspiration of your car, I ask that you make your accumulator inspection video public so other EV FSAE teams can learn from each-other and we can actually start passing tech. Share it with me, Id love to see it!
I love seeing more builds with Enepaq modules :) Did you have experience with other cells and does it compare overall? Was air cooling working well?
where did you guys connected the auxiliary contact of AIR
Did you guys have trouble with using the temperature sensors on the enepaq modules with the orion bms?
Hi, sorry the response is so delayed! I hope you reached out to the team and they already got back to you, but if not: Yeah we did. The enepaq temperature sensors are capacitively coupled to the TS, and the Orion thermistor expansion module requires the temperature sensors be GLV referenced. This combination is not compatible. We made fairly extensive modifications to the Orion TEM to make it work: We essentially applied such a large analog filter to the temperature signals that this noise wouldn’t matter (tau measured in minutes not seconds). This technically meets the rules but it probably shouldn't. We ran the endurance very tentatively for this reason. Orion and Enepaq were not helpful at all in addressing our concerns and as far as I can tell they claimed compatibility before doing any testing whatsoever (and many FSAE teams tired this same combination and failed because of this). My suggestion is If you want to use the Orion TEM, use different temperature sensors. (more involved, but a straightforward packaging problem) If you want to use the enepaq temperature sensors, design your own TEM which is TS referenced, as described in the enepaq datasheet. (more elegant, but less foolproof).
@@timstevens135 Hey thanks for replying! We ended up not ordering the enepaq modules because the cost was very high. We are designing a custom battery solution now.
This passed tech?
It did.