Runaway Supercharger: Freight Train

[Geeber]

Twice in the last two days I've plugged my Model X into a supercharger while traveling only have to have the car start making a noise like a runaway freight train from under the hood. In both cases the charger was doing in excess of 400 miles/hr. In the first case I did a hard reset of the computer which didn't stop it. So I unplugged and replugged in the car. That stopped it. The second time I went straight to the unplug and replug. This stopped it again. I noticed when I replugged in the car the charger was going at 250 miles/hr. I don't know how fast it was going immediately before the unplug, as I didn't check. In both cases the battery was under normal highway driving condition, i.e. at least a couple hours since the last charge and no more than 75 mph travel. Has anyone had this issue? What do you know or speculate on the issue? I still have a full day's drive tomorrow. Hope everything is cool ;-). Thanks.

 

[Gwgan]

That's normal HVAC fan noise for high power charging. Make sure the louvers are opening. Age of your car?

 

[Rocky_H]

That is normal standard operation when the Supercharger pushes really high power--has always been that way. As @Gwgan mentioned, the noise you are hearing is that the car is using the air conditioning system and the radiators on the front corners of the car to actively chill the internal battery coolant liquid. The fans at those radiators start blowing really hard, and get noisy, and a lot of people have been nervous when they first hear it and describe it as a jet about to take off. So yes, normal question to ask, but it is expected.

 

[Geeber]

Thanks. My car is 3 months old. I'm glad to hear it is normal. I forgot to mention that the outside temperature reading when to 81 even thought the day was in the low 60s. What would happen if it was over 100F during charging. Jet engine goes to Falcon Heavy?

 

[Rocky_H]

Thanks. My car is 3 months old. I'm glad to hear it is normal. I forgot to mention that the outside temperature reading when to 81 even thought the day was in the low 60s.

Heh, yes, it's creating a cloud of hot air around the car from how it's blowing through those radiators. If you crouch down near the front wheel wells, you will be able feel the blast of hot air coming out there from where it's getting sucked in through the front of the car and jetted out there.

What would happen if it was over 100F during charging. Jet engine goes to Falcon Heavy?

Yeah, you'll notice that more frequently when it's near 100. The car manages all of this very carefully. It will cap off the charging speed if it needs to sometimes if it can't quite remove the heat fast enough for how much heat it is creating inside the pack from the charging.

Also, one other thing you may notice. If you are sitting in the car while it Supercharges in 105 degree temperatures and have the A/C on inside the car, you may see the car show you a message on the screen sometimes that it is turning off your cabin A/C for a few minutes to divert that chilling to the battery coolant system so it can keep the heat down. And if it's having to balance back and forth like that, it can sometimes have to lower the charging speed, which will make it take longer. So when it is really hot like that, you can help speed things along a little bit by leaving the car and going inside somewhere else to wait, so it doesn't have to try to balance cooling the cabin and the battery at the same time.