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AC draining Hybrid battery

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Grim187, Jul 19, 2017.

  1. Grim187

    Grim187 New Member

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    I drove about 3 blocks earlier today with the AC on and went from two bars from the top to two bars in battery.

    Without the AC I have no problems with battery staying charged above half nor do I have problems with just the fan on.

    I'm thinking it might be the compressor is about to cease, I would think that it would blow a fuse before taking so much of the battery.

    I recently replaced the blower because when I was installing EV mode activation (flasher) the Box needed cleaning and the cabin air filter was the worst I've ever seen. I had previously noticed it was pretty loud and when I got to the motor it barely had any copper left on the rotor where the bushings connected and worn groves into it.
     
  2. davecook89t

    davecook89t Senior Member

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    The battery draining while driving in the city with the A/C on seems like normal behavior to me. Others have also remarked on how quickly the battery drains with the A/C unit battling the heat of the summer. That is my experience.
     
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  3. Beachbummm

    Beachbummm Senior Member

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    as long as you don't get the red triangle of death don't worry about it.. ac is the biggest draw on the system, try raising the temp a few so the ac doesn't run constantly
     
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  4. bisco

    bisco cookie crumbler

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    you have an old car with a lot of miles. installing and using ev mode is stressing your battery and will cause premature failure.
     
  5. Grim187

    Grim187 New Member

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    it's a new battery.

    ya but a few blocks to drop half of charge? we are talking less than 5 minutes, that seems excessive. especially when without the ac it rarely drops below 3 bars from the top.
     
  6. fotomoto

    fotomoto Senior Member

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    What battery? 12V or Hybrid (hi-voltage)? If the latter, from whom was it purchased from?
     
  7. bisco

    bisco cookie crumbler

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    the compressor may be on it's
     
  8. Grim187

    Grim187 New Member

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    hv. I'm not sure, it was replaced about 6 months before I bought the car in may.
    it acts like a brand new battery tho, quick to charge, holds charge well. rarely below 3 bars from the top.
     
  9. fotomoto

    fotomoto Senior Member

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    OK. Costs wise, odds are it's an aftermarket rebuilt with old modules battery.

    Anyway, your original post is very vague. How long did it take to travel 3 blocks? That's like 30 secs around here! In heavy traffic in dense urban zone, that can take 15 minutes sometimes. Has the issue repeated since?
     
  10. jerrymildred

    jerrymildred Senior Member

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    Your battery is getting up there in years, but I've seen it many times on our Gen 2 Prii, even my wife's '07 that has battery cells from a 2015. It is alarming, but can happen in a hurry because the battery is trying to cool a screaming hot car and is also hot itself; plus it's helping the engine until the engine gets up to normal operating temperature.
     
  11. 05PreeUs

    05PreeUs Senior Member

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    If the car will drive a couple miles in EV mode, but QUICKLY drains the battery with the AC on, I suspect your thinking is correct.
     
  12. tpenny67

    tpenny67 Active Member

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    Just recently I noticed on my scan gauge that the a/c was drawing about 10 amps trying to cool the car down. That would be enough to drain the battery in about 5 or so minutes.

    As the car cooled off the a/c drew less and less current, down to about 3 amps.

    If you can buy or borrow a scan gauge, you can see if the compressor is drawing significantly more than mine, which I assume is working normally.

    Posted via the PriusChat mobile app.
     
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  13. 05PreeUs

    05PreeUs Senior Member

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    As ...67 suggests, the AC compressor is variable speed, electrically driven and while bolted to the engine, not driven by it in any way. As AC loads reduce, current should as well, because it will not need as much volume pumped thru the system to maintain temperature. The lower the volume, the lower the head pressure, the more infrequent the condenser fans will operate as well.
     
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  14. Grim187

    Grim187 New Member

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    about 5 minutes. I haven't used ac since.


    i did have it on max cold and it was 86F, the car should have been mostly warmed up from the 8 mile drive before i parked it for 20mins.


    ^


    I might be able to set something up with obd2 and a laptop that would allow me to chart that sensor.
    thanks for the info.
     
  15. edthefox5

    edthefox5 Senior Member

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    Your new hybrid battery is not so new. It's not holding a charge very well.

    Not sure what you paid for the car but a new factory Toyota hybrid battery is close to $4000 all in. Substract that cost from what you paid and see how that math works out.

    So.....what you probably have is a whack a mole battery put together by whackamole industries.
    Original owner battery went bad. And he had it "rebuilt" by WAM and sold it. WAM industries replacing a few battery modules to get it running again and do nothing about all the corroded interconnect in the battery. Now your noticing it does not hold a charge very well. Soon it will throw a red triangle. We see this here non stop.

    Get yourself ready for the inevitable and buy a mini vci on amazon and a cheap xp laptop on Craigslist.
    That way when the car throws dashboard alerts because the hybrid battery has failed you will be able to decipher all the codes.
     
  16. johnnyb588

    johnnyb588 Member

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    Everything seems fine to me. I live in AZ, and when temps get into the 110* range, the AC will drain the HV battery from green to purple in less than 10 minutes easy (most of the time it's a matter of 2-4 minutes).

    The health of your battery is not in question. Drive on without worry.
     
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  17. edthefox5

    edthefox5 Senior Member

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    This is too the OP.

    What your seeing is the first sign of a tired hybrid battery. Mileage is poor and lack of power starts to begin. It will last a while like that and eventually throw a master caution alarm when one module starts to not be able to hold a charge.

    My car is a really good bench test of a G2 and all its foibles. I bought it new 10 years ago and take good care of it.
    It has 110,000 miles and started to exhibit exactly what your seeing last year.

    I purchased a battery charger from hybridautomotive and periodic charges and balances definitely helped but what really woke it up was a full discharge and balance. Although I did not do my discharge exactly as instructed it still really helped. It no longer goes into purple bar at the drop of a hat and my power and mileage is restored. It's been a few months and very satisfied with it.

    There's hundreds of conversations about this system. It works. I highly recommend it.your battery has not thrown any codes yet. When it does it's too late most do not recover without module replacement.

    Good luck
     
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  18. Grim187

    Grim187 New Member

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    I ordered a vci because I need one anyways, i already have a cheap laptop i kept for the pre-bluetooth obdII reader i had.
    I paid $3600 and suspected the battery is a WAM and was going to do a full charge and test individual cells but haven't had time.

    do cell chargers exist and how much are they? or do i have to pay someone to do it?
    they are nickel cad cells right?

    it's still holding a charge well but there are times when it drops bars fast.


    in the span of an off ramp it went from 3 bars down to purple, I had auto-ac on with temp set at 84 (it was 94 out).
    another time i had ac set 3 degrees below outside temp and dropped 4 bars before i left the parking lot (it's a small parking lot).
    :/
     
  19. edthefox5

    edthefox5 Senior Member

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    Yep...its getting tired. Mine was doing the same thing.

    Buy a hybrid battery charger/discharger from hybrid automotive and do a full discharge/charge/balance and it will really help..
     
  20. jerrymildred

    jerrymildred Senior Member

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    What @edthefox5 said! It will most likely add a lot of life to your tired battery. Best done before it throws a code.
     
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