Running the A/C with motor off

Roger3125 · 08-20-2006, 08:14 PM

Can someone tell me the best way to run the air conditioning if you are parked or sitting for a while? Will AC run with motor off? Can it run on battery for any great length of time?

Also I experienced the air not going on after I sat parked with air on for a while. Battery went very low but soon after driving for a while it got back into the green.

Finally decided to try hitting the "reset" button and the air fired up fine. Wondering if this is normal or should I take it in while still in warranty?

Thanks guys (and ladies of course)
Roger3125

Lil Mo · 08-20-2006, 09:05 PM

Not sure if I can answer your question completely.

If I want to run the air conditioning while parked, I leave the engine on. The car appears to drain the battery down until the engine kicks on.

I have never tried it with the engine off.

Cheers,

**efusco** · 08-20-2006, 09:14 PM

"reset button"? I don't know what that is and certainly never woulda thought of hitting it.

But yea, just leave the car in Ready mode with the AC on, the ICE will fire up when necessary to recharge the battery.

And just for a point of information, we Prii people make a clear distinction b/w the "Motor" and the "Engine"

Motor = Electric motor... or more specifically the two Motor Generators (MG1 and MG2).

Engine = ICE or internal combustion (gas) engine

Might seem minor, but I've seen a couple threads spin pretty out of control due to someone not being clear on the nomenclature.

pete bogumill · 08-20-2006, 09:17 PM

hi there. the question on the a.c. just put in park and the prius will do the rest with everything left on.toyota has it all figured out real well.

pete

sub3marathonman · 08-20-2006, 10:36 PM

I occasionally run the A/C like that. I have to start out with six bars. I'll put the car in N, and then set the A/C at Max Cold. Then I will run it about 45 seconds and turn it off for about two minutes, and repeat that until I see the battery getting low to about three bars. If I know I'll be going within a minute I'll let it get to two bars, otherwise I'll turn the A/C off at that point.

By doing it this way you don't run the ICE to keep the A/C going. If you put it in Park the ICE will come on sooner.

Bill Merchant · 08-20-2006, 11:00 PM

<div class='quotetop'>QUOTE(sub3marathonman @ Aug 20 2006, 07:36 PM) [snapback]306500[/snapback]</div>

Quote:

By doing it this way you don't run the ICE to keep the A/C going. If you put it in Park the ICE will come on sooner.[/b]

Since the ICE is the source of all power in the Prius (as in any car), I don't know why you'd want to use this procedure. Running the HV battery low isn't good for it, and you'll only have to run the ICE more/harder/longer to make up for how you drained it.

Just put it in Park in Ready, set the AC to Auto, set the temperature to be comfortable, and relax. This won't use any more gas and you won't strain the battery. Remember that since the AC compressor is a variable speed electric, it will only use as much energy as needed to keep you comfortable, without your hot/cold cycles.

**efusco** · 08-20-2006, 11:09 PM

<div class='quotetop'>QUOTE(sub3marathonman @ Aug 20 2006, 09:36 PM) [snapback]306500[/snapback]</div>

Quote:

I occasionally run the A/C like that. I have to start out with six bars. I'll put the car in N, and then set the A/C at Max Cold. Then I will run it about 45 seconds and turn it off for about two minutes, and repeat that until I see the battery getting low to about three bars. If I know I'll be going within a minute I'll let it get to two bars, otherwise I'll turn the A/C off at that point.

By doing it this way you don't run the ICE to keep the A/C going. If you put it in Park the ICE will come on sooner. [/b]

This is a recipe for disaster. My ICE won't come on anyway until I'm down to 1-2 bars even with the AC running, and if something happened and you forgot to check the SOC and kept he AC going with the car in N you could, potentially, drain the HV battery to a dangerously low level and damage the battery or even drain it completely. You really should not leave the car in N in Ready mode for any significant period of time.

The engineers who designed the Prius did a fantastic job of keeping the general public from screwing things up, but one way you can 'outsmart them' is to leave the car in Ready and Neutral since that is one of the only ways to completely drain the HV battery...the other is to drive until it dies after running out of gas.

Roger3125 · 08-20-2006, 11:21 PM

Can I assume thn from all comments that the best way to have air while parked is to leave the motor running and kick back and leave it alone. During the short time parked it will use no gas or small amount as the motor comes on to charge the battery.

Still not claer on what an ICE is nor what I.C.E. represents. Can someone run by this one more time for us still newbies? Thanks

marjam · 08-21-2006, 01:02 AM

<div class='quotetop'>QUOTE(Roger3125 @ Aug 20 2006, 11:21 PM) [snapback]306524[/snapback]</div>

Quote:

Can I assume thn from all comments that the best way to have air while parked is to leave the motor running and kick back and leave it alone. During the short time parked it will use no gas or small amount as the motor comes on to charge the battery.

Still not claer on what an ICE is nor what I.C.E. represents. Can someone run by this one more time for us still newbies? Thanks
[/b]

The ICE is the Internal Combustion Engine. (Gas Engine). The motor is one of the two electric motors. Yes, you can assume the best way is to stay in Ready mode, shift to Park, set the A/C to where you are comfortable, and enjoy the car.

McShemp · 08-21-2006, 09:15 AM

If you had a car before, and sat parked with the a/c on, then just do what you did before.

If this is your 1st car, park and sit ... don't turn the car off until you're ready to get out.

08-20-2006, 08:14 PM	#1
Roger3125 Senior Member Join Date: Jan 2006 Location: Orange County, So Calif Posts: 179 My Car: Package: Nominated 0 Times in 0 Posts TOTM Awards: 0 Friends: 0	Can someone tell me the best way to run the air conditioning if you are parked or sitting for a while? Will AC run with motor off? Can it run on battery for any great length of time? Also I experienced the air not going on after I sat parked with air on for a while. Battery went very low but soon after driving for a while it got back into the green. Finally decided to try hitting the "reset" button and the air fired up fine. Wondering if this is normal or should I take it in while still in warranty? Thanks guys (and ladies of course) Roger3125 __________________ Super White, Pkg 3, born Jan 3, 2006, ++ClearBra++BT tech brace++Rear bumper guard

08-20-2006, 09:14 PM	#3
efusco Troll Slayer Join Date: Nov 2003 Location: Nixa, MO Posts: 14,211 My Car: 2004 Prius Package: #9 Nominated 1 Time in 1 Post TOTM Awards: 0 Friends: 24	"reset button"? I don't know what that is and certainly never woulda thought of hitting it. But yea, just leave the car in Ready mode with the AC on, the ICE will fire up when necessary to recharge the battery. And just for a point of information, we Prii people make a clear distinction b/w the "Motor" and the "Engine" Motor = Electric motor... or more specifically the two Motor Generators (MG1 and MG2). Engine = ICE or internal combustion (gas) engine Might seem minor, but I've seen a couple threads spin pretty out of control due to someone not being clear on the nomenclature. __________________ Evan E. Fusco, MD Seaside 04BC9/OEM EVb/NAV & auto-BT/XM Radio, CAN-View, Shark Fin, BT Stiff. Plate, Skid Plate & Strut Support

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08-20-2006, 09:05 PM	#2
Lil Mo Join Date: Jun 2006 Posts: 171 My Car: Package: Nominated 0 Times in 0 Posts TOTM Awards: 0 Friends: 0	Not sure if I can answer your question completely. If I want to run the air conditioning while parked, I leave the engine on. The car appears to drain the battery down until the engine kicks on. I have never tried it with the engine off. Cheers,

08-20-2006, 09:17 PM	#4
pete bogumill Join Date: Feb 2006 Posts: 57 My Car: Package: Nominated 0 Times in 0 Posts TOTM Awards: 0 Friends: 0	hi there. the question on the a.c. just put in park and the prius will do the rest with everything left on.toyota has it all figured out real well. pete

08-20-2006, 10:36 PM	#5
sub3marathonman Senior Member Join Date: Aug 2005 Posts: 209 My Car: Package: Nominated 0 Times in 0 Posts TOTM Awards: 0 Friends: 0	I occasionally run the A/C like that. I have to start out with six bars. I'll put the car in N, and then set the A/C at Max Cold. Then I will run it about 45 seconds and turn it off for about two minutes, and repeat that until I see the battery getting low to about three bars. If I know I'll be going within a minute I'll let it get to two bars, otherwise I'll turn the A/C off at that point. By doing it this way you don't run the ICE to keep the A/C going. If you put it in Park the ICE will come on sooner.

08-20-2006, 11:21 PM	#8
Roger3125 Senior Member Join Date: Jan 2006 Location: Orange County, So Calif Posts: 179 My Car: Package: Nominated 0 Times in 0 Posts TOTM Awards: 0 Friends: 0	Can I assume thn from all comments that the best way to have air while parked is to leave the motor running and kick back and leave it alone. During the short time parked it will use no gas or small amount as the motor comes on to charge the battery. Still not claer on what an ICE is nor what I.C.E. represents. Can someone run by this one more time for us still newbies? Thanks

08-21-2006, 09:15 AM	#10
McShemp Senior Member Join Date: Sep 2005 Location: SA, TX Posts: 344 My Car: 2006 Prius Package: #5 Nominated 0 Times in 0 Posts TOTM Awards: 0 Friends: 0	If you had a car before, and sat parked with the a/c on, then just do what you did before. If this is your 1st car, park and sit ... don't turn the car off until you're ready to get out.