FET temperature

[CJPB32]

Hi All.

I bought a Spektrum DX5C transmitter last winter and used it for the first time last weekend with my RTR Impulse 32. Just fun running while on our pontoon boat in a lake.

The DX5C shows the temp of the FET (as well as a bunch of other info) with telemetry. My FET got to about 130F-140F.

The motor, batteries, and ESC were about 100F as shown on the DX5C. This is continuous running at various throttle positions until the batteries got to about 3.5v each cell. Checking temps with my heat gun verified the temps were as shown on the transmitter or actually cooler.

I've searched here and online but can't find much about the FET and the max temp.

What is generally the max temp. for the FET?

Thanks in advance.

[NativePaul]

As with most electronics, and things in general, the higher the temp the shorter the lifespan and the lower the efficiency.
The absolute limit with immediate damage likely is 100c not sure what that is in f but it is the boiling point of water.

I think 140f is about 60c which is a safe range to be in.

ESCs are switching full current to give partial throttle snd switching losses are responsible for most of the FETs heat so counterintuitive time spent at partial throttle heats an FETs up more than time at full throttle, so you may find that going faster lowers ESC temps.

[CJPB32]

Thanks Paul. 100c is 212F so it seems I'm far below the max.