Roadster Air Conditioning

Speaking of the East coast heat wave (from another thread)... my car arrived in the middle of it.

I'm trying to get a feel for whether my air conditioning performance is normal or not. Frankly it's not handling the heat very well. It starts out moderately okay in the morning, but doesn't hold up for long.

In the afternoon the A/C gets very tepid. Yesterday it was intermittently giving me warm air instead of cool. I've not been seeing yellow on the motor/battery/PEM temperature monitors (this afternoon I got a very brief power limit once with the battery going to the yellow - that's it).

A couple of times I ended up just turning off the A/C and opening the windows. That's saying something when my back yard weather station says the temperature peaked at 34.8C (94.6F), with a humidex of 43C (109F).

Now that's pretty hot for Canada, but I doubt it's anything unusual for the southern states (except maybe the humidity).

I know the A/C is shared with the battery, and that the battery's needs outweigh my comfort, but is this normal performance? If that's just what it is, then fine. I'd just like to know.

Other than that the car is an absolute BLAST.

Thanks,

Doug

Okay, that's reassuring. I just wanted to make sure it's working nominally.

Yeah, I got the moisture in the left headlight, first day on the road. I was expecting it given the weather. Drove tonight with headlights on for the first time, didn't notice any impact.

Sheer fun, heck yeah!

I'll send you some pics.

Doug

samcarney said:

Doug I am working this week in Ottawa and you are correct the temp is beastly. I don't have my Roadster with me, that will be a future road trip from Chicago. On a recent trip to Detroit, I found that on the highway when the air conditioning started blowing warm that I could draft behind a truck. This would allow more cool air to enter the cabin do to reduced load on the motor, PEM and battery. After the cooling starts I could go back to normal speeds for about 20 miles, then find another truck. Congrats on your Roadster BTW.

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Thanks for the tips. Probably been doing too many demo drives for friends and neighbors.

I've only been on the highway once with the car, so drafting isn't going to help. I've had hot air blowing at me on a 60kph street. That's why I was wondering if it was normal or not.

Today is ridiculously hot; I might break down and park under the trees at the office. Last three times I did that with my other car I got bird droppings...

Doug

ChargeIt! said:

Are y'all activating the "recirculation" function after blowing out hot air (by cracking windows or "fresh" (warm :frown A/C for a couple minutes) ? Sunreflectors to completely block rays from heating the black dash while parked helps a lot too. Lastly, drive more conservatively so less cooling is diverted to the battery pack ( I know ... what's the fun in that ).

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Yeah, I'm using recirc almost continuously.

I have been pulling back on the aggressiveness, especially in the afternoon. It's just a wee bit hard to resist, especially when I've only had it for a few days.

Doug

Iz said:

You might want to provide feedback to Telsa on the a/c and other issues encountered. I am not a Roadster owner but have read about the a/c and headlight water issues before. Feedback should translate into future improved vehicles.

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Don't worry, they're well aware. Dan Myggen gave me an interesting tip:

"The best solution right now is to charge in range mode during the hottest part of the year, as this will chill the battery. You can either switch to range mode an hour before you leave in the morning, or leave it in range mode over night. If you limit the current a bit, this can keep you from topping the car up all the way overnight, which prevents the little bit of damage to the battery you would see from charging it all the way full. A fully charged car will also limit regen, which can be surprising if you're not expecting it. There is a warning light for this. Leaving the car plugged into 110 during the day in range mode helps for the afternoon commute."

This would be a great solution if I can figure out how to plug in the car at the office. A 110V daytime-only range mode charge wouldn't be able to fully charge the car, but it would cool the batteries.

Dan also said they were looking at doing some firmware upgrades. One obvious thing is to shut off cabin air conditioning when it's counterproductive. A new "cool" charge mode would be really handy - doesn't exceed 90%, but chills the battery.

I suggested providing a user-option to turn on the battery cooling while parked. Presumably that would have some kind of timer so you can't leave it on too long by accident. I would also expect it to cut out if the battery fell below a certain charge level (I'd be fine with a very conservative 50%) to protect the battery from going to full discharge. This option would be very handy for commuting to work on a hot day, when you would be willing to sacrifice some range for a cool drive home!

Doug

AJC said:

I tried using my AC a few weeks ago and it didn't feel like it was operating properly, so I brought it to the local Tesla service and I found out that I had a leak in my AC line. So if you have any doubts, you should take it in and get it checked out.

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Unfortunately Toronto is 400 km away, so it's not exactly convenient to drop in. I'll adopt a wait-and-see attitude...

Doug

vfx said:

Should be mentioned that the 2008 has a much worse AC than following years. (and it's not upgradeable)

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Gosh, if it's worse than the 2010...