But in belt driven AC systems the AC compressor does stop, except the electric blower motors. when the engine stops turning.

You can have the AC stop if the engine stops, in regular stop and go cars. Its just that it gets hot when the Ac is stopped and gets uncomfortable. LOOL

 

Oh c'mon. Belt driven AC runs off ICE off IDLE. This is why, pay attention to tachometer, with AC on, when you stop at red light, engine idle RPMs will be higher than when AC is not utilized. ECU compensates for additional engine load, required to run AC comp, by higher RPMs.
On hybrids AC continuous function is assured by electric AC compressor. It runs independently from ICE RPMs.
I am safely presuming, those non hybrid vehicles that have "gas saving" ICE shutdown during stops, have electric AC comp also. No one will buy a car that "gets uncomfortable" every time you stopped at red or in heavy traffic.

 

You would think lol. Most start stop systems I've seen just run the fan while stopped and the AC compressor (which is still belt driven) remaining off. One more reason to hate these systems, especially in 90°+ weather!

 

Our 2013 Boxster has auto stop and a belt driven compressor. It will fire up the engine as needed for the AC or prevent auto stop from kicking in.

There's also a button to disable it. Sport Mode will also disable it.

 

So today in Bay Area, the temp hit 100+ and wify was going to the beach and she had the A/C on LO with Fan on high.
1/2 hour or 40 miles into her Freeway Drive the RX limped to a stop and display read, "Hybrid System Overheat".
She pulled over and while I took our other car for her to take for her Beach Trip, (another 40 minutes later) the RX turned right on and I drove it home without any issue.
I did however turn the cold setting to 69 degrees and hit the Auto button.

Reading the thread above, I think the A/C compressor drained the Hybrid Battery as it was working overtime to keep the A/C running at full capacity. Although I am surprised that it would be the only reason.
I'll take to the $tealer or my local mechanic and see if there are any codes that come up.

 

Plausible but I'd suspect something else. I've driven from LA to Vegas in 100+ heat with 4 overweight males with 4 sets of golf clubs, and luggage. To top it off, there are straight uphills that are miles long in the desert where temps go beyond 115. I had the temp set at 74 and auto. Cruise control is typically set at 80. At the crest of these hills, I noticed the A/C performance does degrade somewhat. But it gets better as soon as we started going down hill. Again, that is the most strenuous load I have put on the car.

 

Check the coolant level [go ahead and check both coolants] and the radiator is clear of leaves. Also make sure the traction battery vents are clear and nothing is piled up in the rear passenger carpet area.
Salim
Salim

 

So local guy checked codes and nothing pops up. Checked all vents and fluid levels, and all good except there was quite a bit of Transmission fluid on the floor.
He remembered while replacing the front CV Boot a few months ago he added a bit more than prescribed. So he drained some oil and cleaned up. I am monitoring the bottom to see if I see any any more oil and so far with little bit of driving I have not seen any signs of Trans Oil under the car.

QUESTION: do I have to remove the rear seat to get to the Hybrid Battery cooling vents? where is this vent?

TIA
Bob

 

Check the area near the heel of a passenger in the rear seat for the vents to the traction battery.

Salim

 

Drained would not be the best description. The vast majority of the electrical energy used by the vehicle at any given moment is generated by MG1 and/or MG2 (which one depending on speed and power requirements). The battery is just an efficiency buffer. Hybrid System Overheat means that either the electric motors in the CVT overheated (normally they are cooled via an oil cooler and cooler pump), the inverter overheated (normally is cooled by its own coolant system), or the battery overheated (normally is air cooled using a blower located within the battery compartment). Solution is make sure oil level is good, make sure inverter coolant level is good, make sure battery vent is clear.