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Any good way to check on hybrid battery health?

Discussion in 'Gen 2 Prius Main Forum' started by ericspoor, Jul 6, 2019.

  1. ericspoor

    ericspoor Member

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    Hello all, im wondering what methods there might be to check in on the health of a working hybrid battery? I heard of using the dr prius app in conjunction with a bluetooth obd2 scanner, would that be a good way or perhaps techstream is miles better?

    Reason i ask: Im wanting to take a camping trip with my prius and run the AC overnight. The engine has 252k miles, the battery is a 2011 toyota oem battery. In parking lot tests, the ac runs for 4 minutes before the engine kicks on for 1 min, rinse and repeat. I was thinking that was awful early for the engine to have to kick on, maybe because the battery isnt holding much juice? but then again im ignorant on this subject. Other factors: 88 degress outside with ac on max cold.

    Thanks for any and all help!
     
    #1 ericspoor, Jul 6, 2019
    Last edited: Jul 6, 2019
  2. bisco

    bisco cookie crumbler

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    dr prius is supposed to be pretty good. tech stream is the best.

    tough to tell you if your test results in the parking lot are meaningful, too many variables
     
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  3. PriusCamper

    PriusCamper Senior Member

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    Your car is getting old... It's likely you'll get better results with a newer car, but in general, air conditioning uses a huge amount energy and you'd be better off finding a camping location where it's not so hot out. Besides, camping is all about being out in the beauty of nature, not inside your car pumping out engine fumes on everyone because it's too hot out.
     
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  4. fotomoto

    fotomoto Senior Member

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    Back in May, I tried "camping" in my CMax due to a widespread power outage that was going to last for days. Now this is apples to oranges as the CMax has a larger battery capacity in hybrid mode than your Gen 2 but my results were about the same ratio: 2 minutes charge to 9-10 minutes a/c use. Other differences were my garage was hotter than 88f due to the running ICE (garage doors partially open on both ends) and the a/c was set to 72f.

    It was an interesting experiment but one I won't do again on purpose just to camp. Even with ear plugs, I was continually woken up through out the night due to the noise, vibrations and occasionally weird harmonics. It was not a good sleep for me. YMMV.
     
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  5. Skibob

    Skibob Senior Member

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    If you do this please make sure you buy and use a Carbon Monoxide detector. They make them for cars and it’s a good idea if your going to sleep inside a car with the engine going. Even if it’s intermittent.
     
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  6. ericspoor

    ericspoor Member

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    Yep! Definitely thank you
     
  7. fahadw2000

    fahadw2000 New Member

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    At most how much difference should be there between voltage of different blocks?
    And to what limit should the cell voltage drop if a 60Watt halogen lamp is switched on for 3 mins?
     
  8. PriusCamper

    PriusCamper Senior Member

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    It's not so much an exact number... It's more about comparing all 28 modules to each other and putting all the data from testing on a spread sheet and replacing the weakest among them.

    Here's what one of my pack's spreadsheets looks like:

    Screenshot from 2019-07-18 12-18-14.png
     
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  9. fahadw2000

    fahadw2000 New Member

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    Isnt there anything related with Voltage drop. Like in 2 mins what is maximum acceptable Voltage drop?
    Any rough idea...
     
  10. PriusCamper

    PriusCamper Senior Member

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    In my experience older packs in need of reconditioning will lose near 0.4v in two mins and healthy newer recondition packs will only lose 0.2v, but I have to qualify that by saying a healthy newer reconditioned pack can easily lose near 0.4v if state of charge is low to begin with...
     
  11. Prii_socal

    Prii_socal New Member

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    dr prius should be sufficient for normal user, and sleeping in prius? i know someone in bay area do that
     
  12. fahadw2000

    fahadw2000 New Member

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    I did perform load test on mine. I used a 60 watt halogen bulb for 4 mins. Following is the result.
    What I concluded is that cells 11, 12, 13,14, 17 and 18 are all bad and they must be replaced. All other cells did hold the charge quite steady. I think replacing those will solve the problem.
    Plus, I cannot perform that much detailed test as much you have as I do not have equipment for charging etc.

    If I am wrong kindly point me out.
    Capture.PNG
     
  13. PriusCamper

    PriusCamper Senior Member

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    I suspect that not all of those modules are bad, or at least some of them are less bad. The spreadsheet numbers you posted show that the voltage of each module was different at the start and 4 minutes is twice as long as the usual test requires.

    If you have access to a NiMH battery charger that they use for toy remote control cars you can individually charge all the modules up to 8.75v each, then wait for 24 hours or longer and record what the voltages drop down to, then do the load test again for only 2 minutes and you'll likely only have a couple-few bad modules, rather than 6 of them.
     
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