What was that extremely loud sound from my plugged-in 4xe?

[Jeeperz Kreeperz]

I have about 13K miles on my 2021 4xe Rubicon. Had it for a year now, but just yesterday my wife and I heard a sound that we’ve never heard any vehicle make before. I‘ve read somewhere about an electric A/C - maybe that was it? However, I’m not sure why the vehicle would call for that in this particular set of circumstances.

Here’s what happened:

Came home from a few local errands, HVB was down to 10%. Parked Jeep in driveway in front of garage door - as I had a project to work on in the garage. I plugged in 240V Level 2 charger, and immediately began working in the garage with the garage door open. Ambient temp was about 70 F and partly cloudy.

After an hour or so of charging, and no interaction with the Jeep, this sound starts. Sounded a bit like a jet engine turbine winding up as speed increases (but without the turbine whistle). Like a very loud compressor. I’d guess the sound level was >110 dB. My wife and I were both in the garage, and it scared the living daylights out of us. She was panicked, and distanced herself from the Jeep VERY quickly, and I ran over to the wall outlet, and unplugged the 240v cord. We literally thought she was gonna blow!

I then keyed up the Jeep, and it showed a red light on dash for a charging error (I assumed that was from me unplugging the level 2 charger during charge-up). I cycled the key, and that error cleared. HVB showed 68%. I plugged the 240v level 2 charger back in, and all appeared normal, no jet turbine sound. I then continued working in the garage with Jeep plugged in until HVB reached 100% - all quiet while charging from 68% to 100%.

What was that god-awful noise, and is it normal?

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[BXFXJeep]

might have been the radiator fan

 

[LuvHydro]

I don't have an 4xe, but the fan on my Sport S sounds like this sometimes

 

[mllcb42]

The battery coolant pump will occasionally come on during charging to regulate the battery temperature.

 

[Jeeperz Kreeperz]

might have been the radiator fan

Good idea. But why would the engine coolant be hotter than it was one hour earlier when I shut off the engine? Remember, I came back from local errands, using only electric (no ICE), so engine temp should have been cool. Then vehicle charged for about an hour before this crazy loud sound kicked in.

The battery coolant pump will occasionally come on during charging to regulate the battery temperature.

Thanks. You might be right. Strikes me as odd that the vehicle sat for roughly one hour with no use, and then the battery was suddenly too warm, and needed to cool off - given the comfortable 70 degree F ambient temp. But with windows closed, and level 2 charging taking place, I suppose that battery would heat up.

I’m still shocked at how loud it was. My wife and I estimated it to be a similar sound level to our backpack leaf blower at full throttle - as heard from 10 feet away. Dangerously loud to human ears.

 

[Deleted member 72291]

It’s definitely the battery coolant pump/system and that’s perfectly normal. I’d really like to know the software conditions that enable it, because the first time I heard it was on a cold winter day when the Jeep had been sitting in the garage for at least half a day before I plugged it in to charge.

 

[Bzinsky]

Good idea. But why would the engine coolant be hotter than it was one hour earlier when I shut off the engine? Remember, I came back from local errands, using only electric (no ICE), so engine temp should have been cool. Then vehicle charged for about an hour before this crazy loud sound kicked in.



Thanks. You might be right. Strikes me as odd that the vehicle sat for roughly one hour with no use, and then the battery was suddenly too warm, and needed to cool off - given the comfortable 70 degree F ambient temp. But with windows closed, and level 2 charging taking place, I suppose that battery would heat up.

I’m still shocked at how loud it was. My wife and I estimated it to be a similar sound level to our backpack leaf blower at full throttle - as heard from 10 feet away. Dangerously loud to human ears.

the temperature of the batteries is what dictates the charging speed on EV’s.

Batteries always charge with no airflow because you’re always stationary when charging. So the biggest difference between charging a battery at 100amps vs 30amps, is going to be the cooling system and the overall size of the pack(since charging 10,000 cells is obviously going to accept more current than 1,000 cells with no differences in cooling)

i am shocked at it being so loud though.

i guessing there is a small radiator for the battery coolant and instead of relying on a low pressure high cfm fan like a radiator fan, it probably uses something similar to a leaf blower “turbine”

crazy they couldn’t do a better job with the noise

 

[N8213]

Our 4xe sits in the garage right across the hall from my office-very used to hearing that sound. Doesn’t always happen, but usually somewhere between 60 and 85% state of charge.

 

[Sazabi19]

With what everyone else is saying it makes sense that it is needing cooled mid cycle. If you think about your phone charging it also gets warm progressively as time goes. If you use a lower wattage charger it doesn't get it hot and the heating process is a bit prolonged. If you use a higher wattage charger it will get hotter faster as the extra juice comes in.

The same is happening with your 4xe battery except it has active liquid cooling. At first everything is within spec. The batteries are starting to warm up but with the liquid circulating through that helps a lot. But after a while heat soak will set in for the coolant as well. Once the threshold is hit the active cooling of the liquid kicks in to get it back to whatever the set range is.

I have to image all EV vehicles, rather than a mild plug-in like the 4xe) probably have a more robust active cooling system and may be why this isn't an "issue" with things such as a Tesla. Maybe it is, dunno, don't have one. At least it you know it's OK now

 

[Jeeperz Kreeperz]

Thanks all for the answers. The occasional need for cooling mid-charge cycle makes sense. I’m just baffled by the loudness of the system.

@Sazabi19 your point about a faster charge resulting in quicker overheating makes sense as well. As a result, maybe it’s more common with Level 2 vs. Level 1 charging.

We’ve done camping at campgrounds using Level 1 that I plug in when we arrive at campsite late at night. SO RELIEVED that none of those charges resulted in the ‘jet engine take-off effect’ to wake our campground neighbors an hour after plug-in! I’m guessing charging at night, with no sun, lower temps, and Level 1, all contribute to lower battery temps, and less need for cooling.

Thanks again everyone!

 

[2manyhobbies]

Mine would make that sound a couple of times during charging with my level 2 charger, especially if I park the Jeep in the garage during warm weather. It is startling how loud it is - no doubt.

My wife noticed mine making a very small whining sound (no where like the jet engine level noise we are talking about). This noise comes from the passenger front wheel well -and the Jeep was not plugged in. That one really had me scratching my head, but from what I’ve been able to tell, it is normal.

https://photos.app.goo.gl/3QqmwnipFrAH1daq7

I haven’t heard any noises in the last month as my Jeep has been broken down, and sitting at the dealer . I’m told another 3 weeks before it will be fixed.

 

[bjm00se]

110 db - the sound level you described is insanely loud.
None of the normal functions described by others will be anywhere near that loud.

It's possible the noise startled you, and so you over-reported it. If it's truly ear-shattering loud, somethings wrong and if it repeats it needs to go for service.

Of course, weird, intermittent, unrepeatable problems are the worst to try and get fixed.

"Customer states - problem X"

"Performed diagnostics Could not replicate problem X. No further action "

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