When traction battery depletes....

abq sfr · 05-04-2007, 03:04 PM

I attended a Celtic Woman concert this week (FANTASTIC!) however I parked in the adjacent underground parking garage (whatta nightmare). There were only two ticket booths to pay for parking, it took me an hour of inching forward before I got out of there at 11 pm. My traction battery went to the lowest level and stayed there, which is I guess 40% from what I've learned here. Every time I would move forward even a few feet, the ICE would fire up, then shut off when I stopped. The ICE would also start about every 10 minutes I guess and run a couple minutes, to keep the battery from dropping below 40%, but I don't think it ever gained a single bar. Also, the AC compressor would not work, and it got hot in the car. I was kinda steaming from being mad at myself for parking in there, so it got really uncomfortable. Shouldn't the ICE keep the traction battery charged to the point where the AC compressor would function well? Does the AC output depend greatly on traction battery charge?? I think a "regular" car would blow air a lot colder than the Prius did under these conditions. My first disappointment with this car, when it gets 100 degrees here this summer and I'm stuck in traffic, I hope I don't melt down!!

qbee42 · 05-04-2007, 04:01 PM

The AC compressor runs off of the high voltage system, so it does require the traction battery. That said, there is no reason it should fail to run as long as there is gas in the tank and the Prius is turned on. The Prius should run the ICE as needed to maintain charge, and the AC should work fine. Check to make sure your AC settings are correct; if they are, you might need to see your service department.

Tom

daniel · 05-04-2007, 09:24 PM

I agree with qbee: The behavior of your engine was normal. It is annoying, but that's the most efficient way to operate. However, your A/C should have functioned, because 40% battery SOC is plenty to operate it, and the engine will provide the necessary charge. Either you didn't have the A/C set properly, or there is a defect.

**Tideland Prius** · 05-05-2007, 01:36 AM

Hmm... the engine cycling is normal but usually when it drops to one bar, it stays on and charge until 3 bars. I haven't had much experience with low battery (for the sake of mileage) but the few times that I dropped to two, it managed to get to 3 bars without idling (i.e. charge while I'm creeping along).

ekpolk · 05-05-2007, 12:50 PM

Drove your Prius to a Celtic woman concert??? That's just too perfect! :P

Seriously though, somethings astray here. Toward the end of last summer, I was on a long drive and got tired enough that I stopped in a rest area for a snooze. My car is black, and it was a hot day on the gulf coast, so I wasn't about to just shut everything off. With the car in an initially high state of charge initially (from the decel from highway speed), I just put the car in Park, leaned the seat back, and went to sleep. Though I was asleep, I would est that it took ~15 minutes, maybe a bit more for the AC to eat up the charge in the traction battery. At that point, the ICE would come on, run for a minute or so, go off, and then come on again in several minutes later. At no point did the AC falter. Although you were doing the bumper-to-bumper creep thing, and I was stationary, the cars should have exhibited similar behavior.

The general pattern for situations in which the car has substantial HV draw, but not enough regen opportunity to keep up, is for the system to run the traction battery down to the minimum acceptable level, and then start feeding in ICE as necessary to keep the charge up in the acceptable range.

subarutoo · 05-08-2007, 03:25 PM

I was stuck in traffic yesterday for an hour in 91° LA. The battery went down to the last bar, and the engine cycled on and off as needed, but the AC never stopped, or missed a beat. It doesn't happen that often, but it seems to OK for my car.

abq sfr · 05-08-2007, 03:36 PM

<div class='quotetop'>QUOTE(subarutoo @ May 8 2007, 01:25 PM) [snapback]437678[/snapback]</div>

Quote:

I was stuck in traffic yesterday for an hour in 91° LA. The battery went down to the last bar, and the engine cycled on and off as needed, but the AC never stopped, or missed a beat. It doesn't happen that often, but it seems to OK for my car.
[/b]

Thanks for the input everyone... maybe I just had the AC wrong, its so easy to get it wrong in this car, seems like I'm always moving the temp control from max to min and vice versa... and sometimes find the heat on when I think only the blower is on! Climate control controls might be the thing I like the least in my Prius. It should be really simple to go from outside air vent only, AC, Heater, without having to push 3 buttons and a temp up/down button 10 times, especially when outside air only gets you the best mpg! Subarutoo, did your ICE come on every time you inched forward and then shut off when you were stopped? The ICE was not shutting off cleanly either, it seemed to stutter when it shut off. It literally took me 30 minutes to go 100 feet.

IsrAmeriPrius · 05-08-2007, 06:17 PM

<div class='quotetop'>QUOTE(abq sfr @ May 8 2007, 12:36 PM) [snapback]437687[/snapback]</div>

Quote:

Subarutoo, did your ICE come on every time you inched forward and then shut off when you were stopped?[/b]

That is normal when the HV battery is low.

Quote:

The ICE was not shutting off cleanly either, it seemed to stutter when it shut off. It literally took me 30 minutes to go 100 feet. [/b]

It will get smoother as your car gets more miles on the odometer.

qbee42 · 05-08-2007, 10:53 PM

<div class='quotetop'>QUOTE(abq sfr @ May 8 2007, 03:36 PM) [snapback]437687[/snapback]</div>

Quote:

Thanks for the input everyone... maybe I just had the AC wrong, its so easy to get it wrong in this car, seems like I'm always moving the temp control from max to min and vice versa... and sometimes find the heat on when I think only the blower is on! Climate control controls might be the thing I like the least in my Prius. It should be really simple to go from outside air vent only, AC, Heater, without having to push 3 buttons and a temp up/down button 10 times, especially when outside air only gets you the best mpg! Subarutoo, did your ICE come on every time you inched forward and then shut off when you were stopped? The ICE was not shutting off cleanly either, it seemed to stutter when it shut off. It literally took me 30 minutes to go 100 feet.
[/b]

Leave it on AC Auto and adjust only the temperature setting. The Prius does a good job taking care of the details.

Tom

wyounger · 06-08-2007, 05:09 PM

Agreed, leave it on auto. They put a great deal of thought and energy into that system and it makes very good decisions.

I would add, though, that there's no need to adjust the temperature setting so much. You're setting a "desired cabin temp". If it's really hot or really cold in the car the system will work on getting to your setpoint as fast as it can; exaggerating to those temperature extremes won't make it get there any faster. You can actually see that by going into the Climate screen. If the system is in Auto and the fan's on Hi, it's already giving you all it's got.

I've had mine enough to go through hot and cold weather and thus far have not felt any need to override the decisions it was making, and very rarely ever adjust the temperature setting. During the winter I left it on 73 most of the time, and now that it's gotten warm I'm generally keeping it on 71.

05-04-2007, 03:04 PM	#1
abq sfr Senior Member Join Date: Mar 2007 Location: Albuquerque, NM Posts: 624 My Car: 2007 Prius Package: #2 Nominated 0 Times in 0 Posts TOTM Awards: 0 Friends: 1	I attended a Celtic Woman concert this week (FANTASTIC!) however I parked in the adjacent underground parking garage (whatta nightmare). There were only two ticket booths to pay for parking, it took me an hour of inching forward before I got out of there at 11 pm. My traction battery went to the lowest level and stayed there, which is I guess 40% from what I've learned here. Every time I would move forward even a few feet, the ICE would fire up, then shut off when I stopped. The ICE would also start about every 10 minutes I guess and run a couple minutes, to keep the battery from dropping below 40%, but I don't think it ever gained a single bar. Also, the AC compressor would not work, and it got hot in the car. I was kinda steaming from being mad at myself for parking in there, so it got really uncomfortable. Shouldn't the ICE keep the traction battery charged to the point where the AC compressor would function well? Does the AC output depend greatly on traction battery charge?? I think a "regular" car would blow air a lot colder than the Prius did under these conditions. My first disappointment with this car, when it gets 100 degrees here this summer and I'm stuck in traffic, I hope I don't melt down!! __________________

05-05-2007, 12:50 PM	#5
ekpolk The Regenerator Join Date: Jul 2006 Location: Pensacola FL Posts: 363 My Car: 2004 Prius Package: #9 Nominated 0 Times in 0 Posts TOTM Awards: 0 Friends: 0	Drove your Prius to a Celtic woman concert??? That's just too perfect! :P Seriously though, somethings astray here. Toward the end of last summer, I was on a long drive and got tired enough that I stopped in a rest area for a snooze. My car is black, and it was a hot day on the gulf coast, so I wasn't about to just shut everything off. With the car in an initially high state of charge initially (from the decel from highway speed), I just put the car in Park, leaned the seat back, and went to sleep. Though I was asleep, I would est that it took ~15 minutes, maybe a bit more for the AC to eat up the charge in the traction battery. At that point, the ICE would come on, run for a minute or so, go off, and then come on again in several minutes later. At no point did the AC falter. Although you were doing the bumper-to-bumper creep thing, and I was stationary, the cars should have exhibited similar behavior. The general pattern for situations in which the car has substantial HV draw, but not enough regen opportunity to keep up, is for the system to run the traction battery down to the minimum acceptable level, and then start feeding in ICE as necessary to keep the charge up in the acceptable range. __________________ ScanGauge-IIx for the TCH CAN View V3 (for when I care about maximizing Prius benefits). Valentine V1 (for when I *don't* care. . . ). Now in the TCH -- with Remote Display. Black 09 Camry Hybrid Cassis Pearl 07 Avalon XLS Black 04 Prius

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05-04-2007, 04:01 PM	#2
qbee42 Senior Member Join Date: Mar 2006 Location: Northern Michigan Posts: 5,636 My Car: 2006 Prius Package: #7 Nominated 0 Times in 0 Posts TOTM Awards: 0 Friends: 6	The AC compressor runs off of the high voltage system, so it does require the traction battery. That said, there is no reason it should fail to run as long as there is gas in the tank and the Prius is turned on. The Prius should run the ICE as needed to maintain charge, and the AC should work fine. Check to make sure your AC settings are correct; if they are, you might need to see your service department. Tom

05-04-2007, 09:24 PM	#3
daniel Cat Lovers Against the Bomb Join Date: Feb 2004 Location: Spokane, WA Posts: 9,146 My Car: 2004 Prius Package: #6 Nominated 0 Times in 0 Posts TOTM Awards: 0 Friends: 0	I agree with qbee: The behavior of your engine was normal. It is annoying, but that's the most efficient way to operate. However, your A/C should have functioned, because 40% battery SOC is plenty to operate it, and the engine will provide the necessary charge. Either you didn't have the A/C set properly, or there is a defect.

05-05-2007, 01:36 AM	#4
Tideland Prius Super Moderator Join Date: Oct 2004 Location: Canada Posts: 13,900 My Car: 2005 Prius Package: B Nominated 0 Times in 0 Posts TOTM Awards: 0 Friends: 11	Hmm... the engine cycling is normal but usually when it drops to one bar, it stays on and charge until 3 bars. I haven't had much experience with low battery (for the sake of mileage) but the few times that I dropped to two, it managed to get to 3 bars without idling (i.e. charge while I'm creeping along).

05-08-2007, 03:25 PM	#6
subarutoo Senior Member Join Date: Jan 2006 Location: Chatsworth, CA Posts: 1,063 My Car: 2006 Prius Package: #6 Nominated 0 Times in 0 Posts TOTM Awards: 0 Friends: 0	I was stuck in traffic yesterday for an hour in 91° LA. The battery went down to the last bar, and the engine cycled on and off as needed, but the AC never stopped, or missed a beat. It doesn't happen that often, but it seems to OK for my car.

06-08-2007, 05:09 PM	#10
wyounger Member Join Date: Feb 2007 Location: Atlanta, GA USA Posts: 56 My Car: 2007 Prius Package: #5 Nominated 0 Times in 0 Posts TOTM Awards: 0 Friends: 0	Agreed, leave it on auto. They put a great deal of thought and energy into that system and it makes very good decisions. I would add, though, that there's no need to adjust the temperature setting so much. You're setting a "desired cabin temp". If it's really hot or really cold in the car the system will work on getting to your setpoint as fast as it can; exaggerating to those temperature extremes won't make it get there any faster. You can actually see that by going into the Climate screen. If the system is in Auto and the fan's on Hi, it's already giving you all it's got. I've had mine enough to go through hot and cold weather and thus far have not felt any need to override the decisions it was making, and very rarely ever adjust the temperature setting. During the winter I left it on 73 most of the time, and now that it's gotten warm I'm generally keeping it on 71.