New (for me) 2.5 Sport Impressions and 1 or 2 Questions

[Jonathanm]

I have now had my car nearly a week and I must say it is a revelation. Its a 2.5 from 2011. I have spent the whole weekend giving people rides - everyone wants to try. Everyone is blown away by the acceleration and the IMMEDIATE reaction to touching the (noise?) pedal.

My wife had a drive and she really enjoyed it - the steering at slow speed a little hard.

I got it for a good price but nothing compared to what Kokoro is getting!

Anyway just a question about the AC. A couple of times it has engaged during charging - and what a racquet it makes! I really thought there was something wrong but after reading up the noise appears normal. But I have not seen it cut out at all. The radiators get hot and the fans are running periodically. I just would have thought that it would have cut out as it is quite cool - around 10˚C here in the evenings. Any advice/suggestions?

Second thing - as a test I tried to run the AC in the cabin - its is cool at the moment but I put it to fully cold and push the AC button but could not feel a huge difference. I could not see any liquid through the drier window. But there is gas in the system - I checked on 1 of the refilling points.
Is it possible the AC won't run if there is a cold ambient?

Last question - what is the big metal block with the electrical connections coming/going into it? I noticed that there is a red LED on there but I have never seen the LED lite. I enclose a photo...

Otherwise everything else seems to function as it should - but wow - what a car. The last sports car I had was a Honda NSX some years ago - but this is on another planet...

Jonathan

 

[dhrivnak]

On the AC it is common to see it run when charging, especially if charging above 30 amps. At 70 amps it runs most of the time. And the AC is not particularly strong.

And congratulations and welcome to the club.

 

[Jonathanm]

Ok thanks for the reply - I was only charging at 220V domestic European...the other thing I noticed is that when the AC is running there is less power to charge the battery and the accumulating km's takes much longer to go up....maybe its all ok - its just that I'm not sure...

 

[markwj]

Last question - what is the big metal block with the electrical connections coming/going into it? I noticed that there is a red LED on there but I have never seen the LED lite.

It is a DC-DC converter for the AirCon.

 

[Habious]

Ok thanks for the reply - I was only charging at 220V domestic European...the other thing I noticed is that when the AC is running there is less power to charge the battery and the accumulating km's takes much longer to go up....maybe its all ok - its just that I'm not sure...

Yup, when charging, there's only so many volts/amps to go around so, if the ambient temp is warm (or the battery is overly warm), the car will run the A/C to cool the pack down during charging...and there's that many less electrons for the actual charging, so it'll take longer.

Ditto in very cold weather. The pack has a heater in it that the car will engage if the pack is really cold. In fact, if it's REALLY cold, and you plug the car in to start charging, it might not start charging immediately. The car will pre-heat the pack to get it warm enough to take a charge. In very cold weather, you might also notice the No Regen icon (it's a light on the dash that has "REGEN" and a slash through it) illuminated. If the pack is too cold to take a charge, it'll turn off the Regen until the pack is warmed up sufficiently (since regen is a form of charging).

Also, on very warm days (and/or when you're driving the car hard), you may find times when the A/C is running but, all of a sudden, the A/C in the cabin stops blowing cold air. This is (unfortunately) normal. If it needs to, the car will divert 100% of the A/C cooling power to cool the pack down. Usually, when this happens, you only lose A/C in the cabin for 5-10 minutes, then the cool air in the cabin will come back.

The car is very good at doing whatever it needs to do to keep the pack at optimum temperature based on conditions. Also, if there's a problem, the car usually isn't shy about letting you know (via the little VDS screen inside the cabin).

 

[Jonathanm]

Wonderful reply Habious - thank you very much - no alarms as such - have not seen much in debug mode either - so from this I guess I can assume that all is ok...I guess the car understands when there is cold weather so you cannot activate the AC in the cabin. All will become clear in the spring time!

 

[bolosky]

Everything you describe sounds perfectly normal to me.

I charge at 220v 40A, and usually at least the fan runs, and it's very loud. I've noticed recently that it doesn't, but the temp in the garage has been very close to freezing. Much above that and it runs. I'm sure that with higher power it would run with even colder ambient temperatures.

I have also noticed that when it's hot out and I'm trying to charge at 64A (from a Model S charger connected to an 80A circuit with the CAN Sr.) that the PEM sometimes gets hot and the car reduces the charging current to keep it from overheating.

 

[hcsharp]

...I have also noticed that when it's hot out and I'm trying to charge at 64A (from a Model S charger connected to an 80A circuit with the CAN Sr.) that the PEM sometimes gets hot and the car reduces the charging current to keep it from overheating.

This is not normal unless your PEM and/or fans need cleaning. It would also be normal if you reached a state of charge where it begins to taper down. The next time you experience this take a look at what the PEM temps are.

 

[slcasner]

I discovered that the Model S HPWC can reduce the current it will deliver when it gets too hot. I presume this happens by adjusting the pilot signal to tell the car to draw less power. I had not seen this behavior with any other EVSE, so it caught me by surprise when I first observed it at the Rocklin SC. Fortunately we were able to move to a different HPWC indoors with A/C.

 

[bolosky]

This is not normal unless your PEM and/or fans need cleaning. It would also be normal if you reached a state of charge where it begins to taper down. The next time you experience this take a look at what the PEM temps are.

The battery was mostly empty, and it was certainly the PEM temp that was limiting. I don't remember the actual temp off the top of my head, but within a minute or two of its starting to charge the PEM temp would climb up to the highest yellow bar and then the current would back off. This was right after getting the 3.0 upgrade, so you'd think that Tesla service would have cleaned the PEM fans at that time, though perhaps not. When it's in for its next scheduled service, I'll ask them to look at it.

 

[hcsharp]

I discovered that the Model S HPWC can reduce the current it will deliver when it gets too hot. I presume this happens by adjusting the pilot signal to tell the car to draw less power. I had not seen this behavior with any other EVSE, so it caught me by surprise when I first observed it at the Rocklin SC. Fortunately we were able to move to a different HPWC indoors with A/C.

Both the HPWC and UMC (Model S/X) have temperature sensors inside the box and reduce amps via the pilot if it gets too hot. If it reaches temps that high it usually means there's something wrong with it such as a bad connection, frayed wire, etc. I believe all Clipper Creek EVSEs have a temp sensor and shut down if they get too hot. They had a little trouble with early units that were installed in direct sun that overheated mostly from sun exposure. They didn't taper down like the HPWC, they just shut down. Clipper Creek fixed them all with new firmware.

 

[hcsharp]

The battery was mostly empty, and it was certainly the PEM temp that was limiting. I don't remember the actual temp off the top of my head, but within a minute or two of its starting to charge the PEM temp would climb up to the highest yellow bar and then the current would back off. This was right after getting the 3.0 upgrade, so you'd think that Tesla service would have cleaned the PEM fans at that time, though perhaps not. When it's in for its next scheduled service, I'll ask them to look at it.

Definitely a blocked cooling duct or fan problem. It should never climb up into the yellow bars within the first minute or two of charging.

 

[Jonathanm]

Well it takes a while to get to know the car....

After having the car now for a couple of months I have just had doubts that all is ok...It has been winter so there has been no need for the AC when the car has been charging on 220V.
I had a 300 Km drive this week and when I arrived the batteries were a little warmer than normal - anyway the AC compressor started and the range was just not moving up at all - I stopped and restarted and the same thing continued. Anyway in the morning the range had only gone up a little and there was no AC running but I understood the compressor had run for a very long time. I looked in the diagnostics (only just realised that you could access this from more or less any screen) The static refrigerant pressure was 3.5 bar - at 17ºC.

I had another 300 km to do the next day so I though I would get the refrigerant level checked. Well - it was way down - almost nothing in the system. Performed a vacuum test and found no leaks but I guess there must be a very small leak - maybe a dry seal because the car came from a cold country?
Anyway put in the 750gm + a little oil and low and behold everything started up perfectly. The AC works - when charging, the compressor runs for no more than 2 minutes - in fact its a testament to the quality of the compressor that it works as well as it does - I think I gave it quite some abuse.
For those interested the static pressure in the AC system at around 15ºC is 6-8 Bar. When running it is going up to around 16 bar.

The garage attendant was amazed that I had all this information available. They don't get to see these cars (or any Tesla's) in northern Italy. I think I won over a few fans.

Jonathan