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Idling with AC running ok?

Discussion in 'Gen 2 Prius Main Forum' started by J.D. Sowers, Jul 25, 2022.

  1. J.D. Sowers

    J.D. Sowers New Member

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    Hi all! New Prius owner here.

    I just got a 2009 with 175k on it. It had 2 previous owners and regular maintenance at the dealership the whole time. I didn't find anything suspicious in the car fax reports or maintenance records at ToyotaOwners website.so after what I feel was a pretty thorough test drive and with Dr Prius indicating the battery in fair condition I pulled the trigger and bought it. I'm excited to up my mpg game.

    I'm currently delivering groceries and in my market you have to be at the store at 20 past each hour to get offers. Orders are then dispensed at 45 past. It's not a great system and the result is we're left sitting in the parking lot for 25 minutes of each hour just killing time (multi-apping isn't profitable here).

    I'm in the south and during the summer the temps are in the 90s with very high humidity so AC is a must. I'm worried about damaging the ICE or hybrid battery system by idling with the AC on for hours a day. Are my concerns valid?
     
  2. PriusCamper

    PriusCamper Senior Member

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    It's an electric powered system so puts way more demand on your hybrid battery, but if you're driving the car everyday that will be helpful... And if your charge display shows battery charge going up and down rapidly and not staying steady you'd benefit from battery reconditioning. More info here: FAQ (Frequently Asked Questions) | Hybrid Automotive And you can build your own gear for $100: Build Hybrid Battery Maintenance Gear For Under $100 | PriusChat

    And if you can save up for next Summer and upgrade to a Project Lithium pack from NexCell this winter when they're back in stock you'll be very impressed how much your AC performance improves.
     
  3. Tombukt2

    Tombukt2 Senior Member

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    I'm right up the road from you down here in Orange county. 25 minutes of every hour sitting around in my car with the air conditioning on. Not in my car now I parked that sucker under a tree and go into the store whatever Lowe's home Depot Walmart something not sitting out in my car No. You will be asking for trouble and you'll be running the heck out of that inverter and engine charging the battery which is absolutely fine but in a 20-year-old car almost and all of that you want to run it on the bleeding edge then you'll do the necessary repairs. Right now I have the same car with a little more mileage with gold with the beige cross interior the worst in the world. Be looking to do a battery real soon and running it like that you're going to need a good one. And possibly the brake actuator. Itsa coming.
     
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  4. edthefox5

    edthefox5 Senior Member

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    Sitting in the car with the AC on will hammer the hybrid battery. The concerns depend on how fast the battery drains while doing that. Just watch the battery meter on the mfd. If it tanks to purple bars real fast that’s not good but it May do that anyway as your never driving it long enough to put a solid charge onthe hybrid battery anyway.

    A happy G2 hybrid battery is in a car that drives at least 30-40 miles a day on the highway every day, They last the longest.

    Best remediation for your lifestyle is to powerbrake charge the battery.
    When you see it going to purple or worse red bar in Drive put your left foot on the brake firmly with no one in front of you and then gently press on the gas enough till you see the charging bars start moving from the engine to the battery on the mfd. push the gas just enough to start those bars, let that run till you see a blue bar replace the purple bar.

    I did that in my car for about a year at every light till I replaced my battery.

    Bottom line is you have the wrong car for this kind of job.
     
  5. TMR-JWAP

    TMR-JWAP Senior Member

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    Geez, what a bunch of doom and gloomers.

    Guess what? Toyota spent an aass-ton of money engineering the Gen 2. The car will take care of itself. Instead of running the AC in Auto, and at a very low temp, it may be best to just leave the Ac on a reasonable setting or on a middle fan setting. The load on the battery will be significantly less. I did a battery test on my car yesterday (engine not running) and the AC was drawing 12 amps from the HV battery when maxxed out.

    As for your question:

    I'm worried about damaging the ICE or hybrid battery system by idling with the AC on for hours a day. Are my concerns valid?

    Although not IDEAL, the car is designed to cycle within controlled parameters for as long as it needs to. This is no different than the people who use a Gen 2 for camping and let the car idle ALL NIGHT LONG while sleeping in it so they can stay comfortable while the AC cycles. Or the people who have a Gen 2 set up so the HV battery can supply an aftermarket power inverter, used to supply power to a HOUSE, during crazy situations like power loss during a storm/etc, which could result in DAYS of non-stop cycling of the engine/hv battery.

    There is always a chance the HV battery may have some weak cells. If that's the case, you'll find out relatively quickly.
     
  6. rjparker

    rjparker Tu Humilde Sirviente

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    You are cycling the hv battery from a normal high charge to a low charge which then kicks the engine on to recharge the battery. If this was just once in 25 minutes you are probably ok with a very good high capacity hybrid battery. But if it ends up cycling the engine three or more times, you are putting a fair amount of thermal cycling on the engine. When its off for ten minutes it will often cool by 50f. Then it will heat up again each time charging is required. Plus the system will only partially charge the hybrid battery in this idle wait state. Meaning the second and third discharge will be faster.
     
  7. douglasjre

    douglasjre Senior Member

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    JD You had Chrysler products on the past? Leave the past being u maan....

    I leave it idling in summer heat for 4 days straight without moving it. Funny how much water pours out the pipe when i finally get in and drive it
     
  8. J.D. Sowers

    J.D. Sowers New Member

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    Wait, I can screw up the brakes by idling?? That's bonkers. Not saying I don't believe you, I just... You'll have to explain that to me.

    So I guess I have to play the part of "battery management system." I was kinda hoping the car would handle that so I could, ya know, keep my eyes on the road. This sounds dangerous.

    And here I thought "All the uber and doordash guys rave about their Priuses. They're so efficient and easy to maintain they say." but it seems you need an electrical degree and a course in stunt driving to own one and hybrids can't idle.

    I saw a post recently that included an excerpt from the owners manual saying not to run the AC in auto mode when the engine isn't running so that's a good tip.

    Dr Prius says I have 53% life left. If 40% is replacement territory I figure I can squeeze 3 months out of the battery but I'm already researching my options. The best deal I've found so far seems to be Hybrid Geeks in Raleigh. They'll come out and drop a reconditioned battery in for $899 with a 3 month warranty and I can extend the warranty indefinitely for $29/month. I view it as a 30 dollar a month "hybrid surcharge" and I'm totally fine paying that for the roughly $300/mo I'll be saving in fuel. This seems to be the best option as I don't know how long I'll keep the car. This discussion has made me question whether it was really a good idea to buy it in the first place. However if I do fall in love with the car they also have 1 yr, 3 yr, and lifetime warranty options for around $1050 - $1450 all in and their typical lead time is 1-3 days. Stellar reviews on the googlewebs. If there is a better deal in NC that I missed, please advise.

    If the hybrid battery is the only thing I'll damage by idling I'll just go ahead and drop some coin on this option so I don't have to worry about it. If the battery throws a red triangle at me, I'll take an early weekend, leave the car in the parking lot, and summon the geeks.

    No sir, I'm a VW guy. My VR6 GTi only gets 23mpg but it idles like a champ.
     
  9. Another

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    Also watch your oil level and color.
     
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  10. Tombukt2

    Tombukt2 Senior Member

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    You can run these things to your oil is black drain it change it put fresh oil in that turns immediately dark brown and run that 10,000 mi and keep going and going and going so what if that's what's happening that's what's happening you want to start a rigorous reversal and clean all this mess up and do right by the engine in car it may be too late just look at it like that. No I'm not saying by running your air conditioner you're going to break your brakes no sir that's not what I said I said be prepared driving and using the car like you are to put on a break actuator in a generation 2 Prius it is going to come up being driven under these conditions almost guaranteed you might be one of the lucky few who slides through and doesn't have to do a thing but don't bank on it I would be locating the part and have it on standby in your 09 me personally I have two or three of these cars and always keep one at the ready so that I don't have to drive my 12 gallon to the mile van ever except when it's loaded I don't have broken down Prii at the house. I have them rolling and running or stripped and going to the junkyard Good luck
     
  11. ChapmanF

    ChapmanF Senior Member

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    Playing devil's advocate ... I know Gen 3 does apply the brakes every time it starts the engine when parked, as a way of holding the body lurch to a minimum.

    I've never really paid attention in a Gen 2 to find out if it also does that.

    Taking the devil's advocate hat back off, I don't think I'd be very worried about that added number of mild brake applications noticeably hastening the demise of your actuator.
     
  12. J.D. Sowers

    J.D. Sowers New Member

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    Ok I get ya. That's a good tip. I'll keep an eye out for a good deal on a brake actuator and probably an EGR valve. I know most like to clean em up but I'd rather take it to shop and have them replace it so I can get back on the road quick. If the old one is salvagable I can clean it up in my spare time and have it ready for next time.
    Also gonna keep an eye out for spare headlights or is that just a gen3 issue?
     
  13. rjparker

    rjparker Tu Humilde Sirviente

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    Most people would agree buying a high mileage 10-15 year old Prius is not the most cost effective commuter or delivery vehicle if major maintenance is considered. The gas savings won't compensate for a couple of high dollar engine, brake booster or battery issues. So most of the comments in this thread relative to "wait idling" are focused on reliability in your ownership.

    The smart money does not believe in or buy used batteries from "reconditioners." The original cells lasted ten or more years with reliability. After buying "reconditioned" and experiencing several week long downtimes to replace bad cells again, most reconditioned battery buyers recognize the downside. Especially when new cells start around $1,600.

    Power braking the engine in Drive to fully charge the "wait idle" battery is poor practice but is the only way to override the more conservative but frequent charging the car is programmed to do, as I described above.

    Your engine and hybrid battery is at risk longterm with long and frequent wait idle periods. Not that it will overheat and fail immediately. That may be a concern for those sleeping in the car in a Ready state. It does not need to overheat and probably won't. However, large thermal cycling of the engine temperature is a result of wait idling. It can accelerate carbon buildup or oil consumption issues. Luckily your gen2 is not prone to head gasket failures but wait idling is not good in that area as well.

    Honestly, I would buy a nice rechargeable fan if regular 25 minute waits were required. After I was tired of that, I might find another job that did not require my car running all day. Perhaps in the store.
     
    #13 rjparker, Jul 26, 2022
    Last edited: Jul 26, 2022
  14. rjparker

    rjparker Tu Humilde Sirviente

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    The difference is this guy is doing it everyday, 25 minutes per hour, in a high mile hybrid.
     
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  15. douglasjre

    douglasjre Senior Member

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    It amazes me how something so simple can be made to sound so complicated. JD, feel free to idle away and enjoy your car
     
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  16. J.D. Sowers

    J.D. Sowers New Member

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    I'm not even going to get into the whole "why don't you just get a different job" comment because that's not the point here. I love my job and while it's only been a week the car is growing on me. Every car has it's weak points. My GTi has weak timing chain tensioners and a plastic coolant bypass tube that's prone to cracking so I've already sourced upgraded replacements. The prius is no different. When you put a ton of miles on a vehicle you're going to replace stuff. It comes with the territory. If you prepare ahead of time the downtime is manageable, especially with a backup car or rental coverage.

    I found a place that installs new cells for around $2k. They say a new pack has a life expectancy of 8-10 years but they'll only warranty them for 3 so it seems they don't really believe in the product they're selling. Please tell me more about these $1600 new batteries. Is that installed? What are the warranty options?
     
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  17. J.D. Sowers

    J.D. Sowers New Member

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    I'm not sure who "most people" are but their is widespread concensus among delivery drivers that the prius is one of if not THE best car for the job. It has decent cargo space, great mpg, and is the used car with the cheapest lifetime maintenance.

    I found a few online articles about the "best cars for delivery" but I'm not allowed to post links yet. Spoiler though: Prius tops every list.
     
  18. lech auto air conditionin

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    You definitely will cycle your battery many times a day if you’re doing this for a delivery service and you intend to keep your AC on all day long as I do.

    A battery has a Finite cycle life. It does not matter what the chemistry is or who manufactures it there is a limit.

    in my business I start at 7 AM I get home at 7 PM my car turns on and my AC button has not been turned off since the day I bought my 2012 Prius C

    like a boat or an aircraft you do not measure in miles you measure the engine life on how many hours it is on.

    knowing this I prefer comfort and quality of life in my daily business to be comfortable in my vehicle as I travel from shop to shop.

    and I know I will be purchasing a battery prematurely.
    So even though my battery just hit over 100,000 miles my battery died. It gave us slow death towards the end starting at about 85,000 to 90,000 miles a few intermittent dead batteries what’s the warning light on the dash in a couple times signaling to me the battery started discharging very rapidly so I knew it was about to happen it was no surprise.

    finally died 100% and would not start back up even after resting.

    I disconnected the 12 V battery for a few minutes got on the phone call Luscious Garage and have them order me a new battery. Went over and picked it up $1900. 45 minutes to replace the battery it was very easy and I still run my AC on all the time never shuts off and I let my vehicle idle all day long keeping my cabin cool and comfortable.

    in another hundred thousand miles I’ll just get another battery and replace it again.

    change my oil every 5000 miles with Amsoil signature series and like all my other engines I should be able to hit 400,000 miles no problem because idling is the hardest thing on your engine oil.
     
    #18 lech auto air conditionin, Jul 27, 2022
    Last edited: Jul 27, 2022
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  19. Another

    Another Senior Member

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    Yep, you nailed the issue, that’s the problem, warranty vs representations.
    Just look at the Project Lithium guy. Even he doesn’t stick his neck out. Two years. And that assumes he’s still in business by then.
    Even a Toyota OEM replacement is only one to three years warranty depending upon who installs it. At least you know they’ll still be around though.
    The longest warranty term that I’ve seen on a replacement battery is from GreenTec at four years with new cells. Their prices have increased over the past year, now $2,250.
     
  20. lech auto air conditionin

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    That’s why they’re used for taxi cabs in San Francisco’s streets and hills. 375,000 miles easy. Front brake pads most last 200,000 miles in San Francisco that’s unheard of with all our hills.

    I can’t Think of any other vehicle better for delivery not to mention the savings on gas.
     
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