Battery fan loud at speed over 60 km/h

[bearer]

Hi, I have had a Jazz MK4 for about a year. Recently, my attention has been drawn to the fact that as soon as I exceed 60 kilometers per hour the battery fan (near right rear seat) runs noticeably loud. Not in intervals, just blowing/pulling evenly all the time (at slow speeds it is quiet). Depending on the occupied position in the car it is more or less audible, but in the driving position I can hear it very well.
I'm wondering if by some chance I just didn't pay attention to it before, or if there was some change in the fan's operation after all. I checked the battery vent duct at the right rear seat, it looks OK, the seals seem fine. Is the behavior in your cars the same as mine or is there a defect after all?

Thanks

[Lord Voltermore]

I have never noticed mine . Sometimes once you become aware of a noise you tend to concentrate on it and it seems to get worse.     Was your check of the vent enough to say nothing has been sucked into the fan such as a leaf or sweet wrapper? 

You could ask the dealer to have a listen.    They might have a way of getting the fan to run without  a test drive.  Or try doing a sound recording using your phone that they could listen to. 

[ahavoja]

I have never noticed mine either. Next time I'll try to listen more carefully. Does your fan run in any weather or only when the weather is hot?

[ahavoja]

I just did some driving with the rear seat folded down so that I could hear the HV battery fan more easily, because the rear seat hides the fan intake vent. Here are my observations:

During the first minutes of drive the fan didn't start. I drove up to 100 km/h and it still didn't start. Then I floored the accelerator pedal at motorway speed, and I could hear the fan starting and the fan speed increasing. After the motorway the HV battery had warmed up and the fan started at 40 km/h, sometimes at 60 km/h, probably depending on how warm the battery was.

When the fan starts, its speed increases very gradually, at the same time as the car's speed increases, so the noise of the fan blends very well with the road noise. Maybe that's why I haven't noticed the fan before.

but in the driving position I can hear it very well.

I think either you have very good hearing, or your fan is noisier than usual, because I'm still not 100% sure if I heard the fan or if it was just road noise.

[madasafish]

There will be  a filter. It may be blocked.

[Jazzik]

There is no filter...

[Kremmen]

Not noticed mine either, and I'm tooling around with rear seats down as I'm in house DIY mode

Check the vent isn't blocked and get it looked at. An overheating HV battery is potentially dangerous. Look at those e-scooter and e-bike charging fires

[bearer]

Thank you for checking. It seems that the fan works fine. I noticed that how much the fan sound is heard strongly depends on the driver and passenger seat settings. In some settings the sound is more or less pronounced. I did not find anything in the air outlet. The fan speed increases with speed, when driving up to 50-60 kmh it is basically inaudible.

[Lincolnshire Rambler]

Gosh think i need a hearing test as i never knew the jazz had a fan for the HV battery .  But i always have the radio or apple car play on …