Active Workpage, so everything is still being worked through. Just a useful reference for anyone to see where the progress is. For updated information on everything ask Battery Box for access to Battery Box Trello.
Main Tasks:
Fan Selection and Cooling
Adhesive Selection
Board Mount
Things happening soon
Fan testing with wind tunnel
Talking to Micah
Fan Selection and Cooling
Purpose
Cells generate heat while in use due to internal resistance. We want to remove heat from the battery box to prevent overheating of the cells, which can cause thermal runover and damage our modules.
We are interested in comparing the 120mmx120mm fans to the 80mmx80mm fans to check if 80mmx80mm fans are able to provide enough airflow, but also to check if air will mostly pass over the modules in a 120mmx120mm set up. As a result, we may want to put a wall or something above the modules in the 80mmx80mm test so that the anemometer only takes the airflow from the air going through the actual modules.
Basics Background Information (more or less):
The PQ Curve is a characteristic of the fan. It shows the relationship between the airflow that the fan provides (in units of CFM or cubic feet/minute) and the static pressure is how much air pressure the fan creates in the system, intuitively we can see it as how “hard” the fan “pushes” the air.
There is another line/curve that is the Load Curve, also called the System Impedance Curve, or the System Characteristic Curve. It is a characteristic of the system where air is flowing. So our battery box with 9 modules would produce some Load Curve, and another box with only 2 modules would also produce some Load Curve.
The intersection point between the Load Curve and the PQ Curve provides the “operating point” of the fan. That is, the actual airflow and static pressure of the fan in that system. Actually trying to figure out how a fan will act in a system without any testing is kind of impossible as a result. Any fan can technically give the load curve, but if you get the load curve with an absurdly different fan it might not be so applicable.
Why airflow - static pressure testing and not just straight up temperature testing? Because even if you get some graph of the temperature based on the airflow, you can’t really extrapolate that on to how much temperature will be removed with more modules because the airflow itself is going to change based on the added modules.
Our Task
We will be doing a wind tunnel test similar to what Micah did (Testing - Airflow Through Modules), except we will be testing different fan sizes, and just more fans in general. We will build our own cardboard wind tunnel for testing and evaluate the data that we get following a similar process to what Micah did here (Battery Pack Cooling).
List of Fans We Want to Test:
Noctua NF-F12 IPPC 3000 PWM 120mm https://noctua.at/en/nf-f12-industrialppc-3000-pwm
Noctua NF-A8 PWM 80mm $21.11 crid=223FQ9UUG3JJS&keywords=noctua+fans+80mm&qid=1688164914&sprefix=noctua+fans+80mm%2Caps%2C78&sr=8-4
PQ Curve: N/A
Arctic Fan F8 PWM 80mm
PQ Curve: https://support.arctic.de/en/f8-pwm/docs
Phanteks 120mm ($34.99), outperformed Noctua 120mm fans: https://www.amazon.ca/Phanteks-PH-F120T30_BG_3P-Triple-Pack-high-Performance-Excellent/dp/B09B2LNFV4?tag=hardwar06-20&geniuslink=true
Noctua NF-A9 PWM 92mm https://noctua.at/en/nf-a9-pwm
PQ Curve: N/A
Adhesive Selection (will update later, but epoxy is looking very nice)
Board Mount (will update)