Wiring two fans

So I’m trying to hook up two cooling fans for my KITTAZ w/ dual extruder, 24V PSU. I had spare 12V fans lying around so I figured I’d try to hook two of them in series. Should work in theory, right?

They’re Sunon fans, 12V/0.13A/1.6W. When I plugged them in and tried to run them, they won’t work. They “twitch” a little when I feed them power, as if they’re not getting enough juice to actually start running. They’re light loads so I’m not sure why they behave this way.

Against my better judgment I did try hooking one of them directly and it does run but only once I up the PWM to 244/255.

I’ll order another 24V fan and hook up two in parallel if I have to, but I’m wondering if there isn’t a way to make this approach work first. Is there something I need to modify in the firmware?

Note that I’m planning an upgrade to dual e3d’s soon so I do have to have two fans running off a single mosfet.

These types of fans are not inductive motors, so therefore wiring them up in series will not work. They are microprocessor controlled BLDC motors. You need to run 24v motors, and if you want 2 fans, you need to run them in parallel.

Most 12v fans will last for a little bit on 24v, but eventually the microprocessor will smoke.

Gotcha, thanks for the clarification!