Orion2 BMS PWM fan control

[hallkbrdz]

The Orion documentation discusses using the PWM fan output with an external controller. Am I right to assume that this refers to the one built into a fan?

I'd like to run 4 120mm Noctua NF-F12 iPPC-24V-3000 fans off this speed output for battery cooling (system is 18v based).

 

[flippy]

its more useful to use a dedicated set of temperature switches glused directy onto cells around the pack and use that to drive your cooling. i am not a fan ( ) of using a bms for such things. if rather have a simple temperature controlled switch.

still, if you get such heating under normal operation it might be more practical to loof for cells that dont heat up as much under the load required.

 

[hallkbrdz]

I received a reply from Awert. Yes - although I will need to make a simple resistor voltage divider to lower the 18v pulses to 5v.

Flippy, I would agree in general about having more cells to distribute the load, but this is for a racing vehicle where the weight is already high. Still, at worst (end of race) on average over a lap they are still just over 1/3 of the advertised C rate. I'll have temperature sensors on every bus bar plus a few in front of the fans, so the BMS will have plenty of data to go on to throttle the fans for the 7 minutes of the final race. And it things get too toasty, full cutoff.

Now if I could just get some 4680 cells...

 

[flippy]

dont measure the bus bar, measure the center of the cell.

if the race is that short: just turn the fans on when the race starts. no need for temperature sensing.