24v23 High Power Controller running at high amps

Hello,

I have a High-Power Motor Controller 24v23 controlling a trolling motor on a small boat. I am concerned with overheating issues. The controller is rated for 24v and 23 amps without a heat sink. However the motor only draws 12v, but at 45 amps. My question is, can this controller handle this type of loading or is the current simply too high, causing overheating?

Thank you

Hello.

You definitely cannot pull a continuous 45 A from that controller in its default configuration, but you might be able to get there with the addition of a heat sink. Note that the MOSFETs have a theoretical maximum continuous current of 90A at 25°C, but dissipating enough heat to keep the MOSFET at this temperature is impractical for most applications.

- Ben

I do have a heat sink attached to the motor controller, though I am not sure how much it is helping. Do you have any suggestions of a new motor controller I could try that will operate at this current?

The SMCs have integrated temperature sensors, so if you can get a cable between it and a PC while it’s running, you can see how effective the heat sink is and get some sense for what might need tweaking. It’s not clear to me from your posts: are you saying you’ve tried it with a heat sink and the controller is overheating? If so, how long does it run before overheating? Do you have any forced airflow over your heat sink?

Dimension Engineering has some motor drivers that they claim can do 50 A continuously, but I don’t have any experience with them.

- Ben

I have taken this project over from another group and they used the motor controller with a heat sink. In calm water it ran fine, but in choppy water, it overheated. Unfortunately I do not know how long it ran until it overheated. I do not have forced airflow over the heat sink, since it has to be in a sealed container to remain waterproof.

It sounds like it’s close to working, then. Do you have the ability to try a bigger heat sink? If you can find a way to get heat out of the enclosure, you might be set.

- Ben