Is it normal????

[neweuser]

Is it normal for the motor to get warm when you plug the batts in and you don't run it?

[Sylvester]

Not really, how long were the batteries connected?

[neweuser]

Last night i ran it for about 3 min, drove it by me to feelthe motor. It was warm. I let it sit for a minute or more, and it was even warmer? It seemed like it was getting wrmer the longer it sat. Then i drove a little more and it became cooler again? Weird...I have a thread going in General electric about the batts to see if that could be my prob. But also my batts are only a few months old....

[HotnCold]

I would say - no - and i dont think it matters if you have the batts plugged in - the motor shouldnt get hot.

[Dafni]

Well, if you just plug it in and let it sit, it should definitely not get worm. When you drove it, however, it will get a bit warmer when you let it sit. Reason being the sudden lack of airflow. Heat gets not generated in the can, but inside the motor. And it get's only cooler on the outside, where it has contact with the air. If your truck moves, air flows over the can and displaces heat. But when you stop, the heat distribution in/on the motor gets more even (magnet cools down, while the can might get warmer)
No new heat is generated, though, it just moves to the cooler area.

Hope this helps
DAF

[neweuser]

helps greatly, i think that's what's going on. It doesn't get hot fast so....I guess a lot to learn with brushless!!!! This will be interesting! thanks guys!

[Dafni]

Welcome. And it's not necessarily a BL related phenomenon, you find this everywhere. Sudden lack of cooling/airflow, while more heat is traped or stored inside a body. Nitro engines are another example. When you measure the temp on the head directly after a run, shut it off and wait a moment, the actual temp on top of the head increases a bit.
In E motors this effect might be more drastic, because our magnets and windings store a lot of heat energy. (relative high effective heat capacity)

[neweuser]

That makes tons of sense....great explaining man!

[Gustav]

Like in racing when brakes set on fire in the pits or in parc ferme after a race,that's why they have a cooling down lap.