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M3LR 2020 fan running when vehicle unattended

This issue has occurred several times over recent months and I can’t put my finger on it.
I have driven car both short and long distances prior so I don’t think it’s battery cooling. Upon returning to the car sometimes minutes sometimes up to an hour there is a fan running somewhere in the front. It doesn't matter if unlocked or locked.
If I open door the fan stops, so I’m not able to look at the various controls to see what running.
Air con is off, in fact everything is off including sentry. Sometimes it will loose 1 or maybe 2% if left for a few hours but not always, that’s what’s odd about it.
Has anyone any idea what it might be & can I stop it so reducing battery loss.
One more clue, I’ve never known it do it when garaged!
It's normal - it's in relation to the battery warming/cooling and whatever else the cars battery management system has decided to do - its effect on charge level is worse when you do lots of short drives as the car goes through the whole preparing the battery routine which normally takes longer than your drive - battery temp. etc has only a little to do with what the actual external temperature is (although obviously, it will be much much colder in winter than summer).

Nothing you can do about it - it's automatic.

Although check you don't have; Cabin Overheat protection turned on (probably not an issue at the current time of year) and that your easy entry profile doesn't have any weird climate settings setup on it (if you use it).

Also to add in: It should only be doing it after driving / you've disturbed it... it shouldn't be kicking in 3-4 hours after you parked up and left it - if it is then it's something else that's causing it.
Mine does that too, I think it's the HVAC blower running to prevent dampness in the system. My previous Volvo V90 used to do the same. I can hear the noise coming from below the windscreen. It happens quite regularly and maybe related to living by the sea which naturally has higher humidity. I have overheat protection switched off.
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Thanks for the quick response guys. Cabin Overheat protection is definitely off and I never use scheduled departure, so it’s also off, cabin overheat protection is never used & teslafi doesn’t show anything either.
I’ve commented and posted screenshots before on this forum that my car seems to behave itself in terms of idling and sleeping, so they are not affected, she still sleeps like a baby.
It does only appear to do it during the first hour after being left, the duration doesn’t seem to relate to the preceding drive time.
From everyone’s comments it does appear a normal process of hvac & battery cooling.
I would say that's normal (although that doesn't explain it), as mine does it...

I was went out to clean my car the other day and the fan was running for no particular reason, and my neighbour asked what it was doing. I literally said "I have no idea, the car pretty much decides what it want to do, and when it wants to do it".

I treat it like my PC and phone these days, and just let it get on with things :p
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Feb 12, 2020
I think it is normal, from the Maintenance section of the owners manual:

'… Also, even when not in use, you may hear Model 3 emit a whining noise or the sound of water circulating. These sounds are normal and occur when the internal cooling systems turn on to support various vehicle functions, such as maintaining the 12V battery and balancing the temperature of the high voltage Battery. …'

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