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Hybrid Battery Issue

Discussion in 'Gen 2 Prius Technical Discussion' started by tjsadler, Oct 24, 2017.

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  1. ericbecky

    ericbecky Hybrid Battery Hero

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    Since you will likely have to replace modules on an ongoing basis, you may want to buy 1 small charger that is capable of charging/topping off a single module.

    That way you can get the module close to the same voltage as the rest before sticking it in the pack.
    Within 0.1v would be a good target.

    The voltage won't matter quite as much if you are fully charging/discharging/balnacing the entire pack after before actually using it in the car.
    But the closer you can get it, the better.
     
    #21 ericbecky, Oct 26, 2017
    Raytheeagle and 2k1Toaster like this.
  2. greasemonkey007

    greasemonkey007 Active Member

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    I cut a connector off a headlight and wired the high and low beams together. Throw in a switch and some meter leads and voila!

    I do 3 cycles of reconditioning and then load test all modules. That way they've had a chance to improve if they're going to. I use a stopwatch to make sure they're under load for the same time. Then you'll be able to see how much they drop and compare values.
     
    #22 greasemonkey007, Oct 26, 2017
  3. ericbecky

    ericbecky Hybrid Battery Hero

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    Do you watch the data live in your car after doing this?

    Seems like it is easy enough to see who the laggards are over time. Also you could use an app to download/graph the data and just periodically look at that to preemptively see which one will be failing next.
     
    #23 ericbecky, Oct 26, 2017
  4. The Electric Me

    The Electric Me Go Speed Go!

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    That's fine.
    My only comment would be SAFETY FIRST.
    The Hybrid Battery is high voltage. Potentially deadly.

    You may have 20 years experience keeping standard ICE vehicles going...but this is new uncharted territory.
    Be careful.
     
    #24 The Electric Me, Oct 30, 2017
    strawbrad likes this.
  5. tjsadler

    tjsadler Junior Member

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    Ok. I removed the battery and ran the charge and discharge cycles. I then tested the individual cells. Here are the results. Module 5 is obviously bad. 19 is a bit higher than the others but the drop on load is proportional to the others. For the load test I used a 55watt halogen bulb and a timer to check each for 20 sec each. Block 3 showed bad in techstream so module 5 fits with that.

    Now I need to figure out how to pick modules to purchase.

    PS. The voltages are higher than what most people have recorded which I think is because I had run the whole charge and balance cycle on the Prolong unit.
     
    #25 tjsadler, Nov 19, 2017
  6. dolj

    dolj Senior Member

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    You have done enough to confirm that module 5 is bad, but just a couple of comments on your methodology, which goes toward answering your "how to pick modules to purchase" question.

    • Wire the high and low beams together in parallel to increase the current load.
    • Let the discharge go for at least 120 secs.
    • On your data sheet add a third column which is the delta of start and end voltage. (The end voltage is the voltage at the 120 sec mark before disconnecting from the battery.) So starting voltage (8.35 V) – ending voltage (8.22 V) = delta (0.13 V). This will make it easier to match with your replacement candidates, as you will do a similar charge/discharge/charge conditioning on your candidate modules before doing the load test. The module to choose in one that matches your existing modules.
    Overall good work so far, you're well on your way to having a repaired battery.
     
    #26 dolj, Nov 20, 2017
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