extreme heat

[ironjaws]

Looking for some numbers to go by when checking temps.
what would be max motor-esc-battery temps after running? Im sure by the time we get the boat out of the water and to the dock and get the tape off the temps on at least the esc and motor are down 20 degrees already from what the were running at?

[rol243]

temps will rise when boat is out of water, as all water cooling has drained out. not sure on the actual temps of these but if you can,t touch any units with a finger its too hot.

[NativePaul]

60c is the absolute max for LiPos any more and they will puff whether in use or left in a hot car etc. The rest doesn't have a hard limit and the maximum temperatures will vary from product to product, but in general electronics like ESCs are at a very high risk at 80c and motors at 100c. It is not like a switch though with them being safe below those temp, the higher the temp the highest the risk of failure, and I would try to keep temperatures at least 20c lower than those temps (with the exception of LiPos which degrade with every run, and more so at higher temperatures, but like to be at 40c in use, lower temps are detrimental to internal resistance, so a lower start temperature can result in a higher end temperature and more cell degredation).

[RandyatBBY]

There has been a lot of discussion about heat on cells, ESC and motors. First off anything that is over 110F/43.33C will burn the finger so a meter is needed. I have used as a base line of 140F/60C the max for all three. (Cells , ESC and motors) I feel that the lower the temps the longer the life of all except in the case of motor and amp draw. I have found that you can have a motor running in the correct temps and pull too much amps and the winding leads will short and puff out the magic smoke.

[kfxguy]

My rule of thumb (personal) is to keep things below 130f (esc, motor) and batteries below 105f. If temps exceed this then changes are made. The only thing that is an exception is my straighline speed boats. I only make one or two passes and I've seen 190f in my logs on the controller (which I'm not so sure is an accurate temp reading anyway because my temp gun showed differently....but that temp in the log is directly on the board) and they have lived.

[Fluid]

temps will rise when boat is out of water, as all water cooling has drained out....

Not true. Logged ESC data shows the ESC temperature can drop by 20*-30*F in just a few minutes. Batteries will begin to cool immediately since there is no more energy being created. Ditto the motor, but due to the reduced mass and increased thermal conductivity the motor will cool faster and more unevenly than the packs.

Measure the ESC on the boards and the caps. Measure the motor on the endbell, not the jacket. Measure the packs in the middle. Bottom line - un-tape and take the temps immediately after pulling the boat out. Waiting a few minutes can give very erroneous results.


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[Tamelesstgr]

The ESC when no longer powering the boat will cool quickly, here is a glimpse of my temp probe which is in the cooling plate of my ESC's

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At least in my experience my log shows the motor temp increases after the boat stops moving. On this graph below the boat stops running when the Gray line starts dropping, that's the ESC. The blue line is the motor. You can see it comes up to running temp and then levels out at the end of the run. Once the run stops, the temp climbs and levels off again (heat soak) my temp probe is in the endbell at the top of the windings.

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[RandyatBBY]

The ESC when no longer powering the boat will cool quickly, here is a glimpse of my temp probe which is in the cooling plate of my ESC's

152063

At least in my experience my log shows the motor temp increases after the boat stops moving. On this graph below the boat stops running when the Gray line starts dropping, that's the ESC. The blue line is the motor. You can see it comes up to running temp and then levels out at the end of the run. Once the run stops, the temp climbs and levels off again (heat soak) my temp probe is in the endbell at the top of the windings.

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Usually I do not try to disagree with Jay Turner most all the time he is right. But, in this case I have to agree with you. I have real time info, On board telemetry. that has shown motors do rise in temp once the use and cooling has stopped.

[Tamelesstgr]

I've talked with Jay about the heat soak in motors, that's where I got my info

[rol243]

what i mean is you need to check the temps as soon as possible when the power has been stopped as heat will rise when cooling has gone. this is very common with nitro and gas powered engines, you must check the temps straight away without waiting too long.

[kfxguy]

Usually I do not try to disagree with Jay Turner most all the time he is right. But, in this case I have to agree with you. I have real time info, On board telemetry. that has shown motors do rise in temp once the use and cooling has stopped.

I've seen the same thing in my logs. I'll make a run. Let boat sit in the water, temps will rise. Then make another pass and temp goes down during the run and then up again after the run.