Prolong Charge - what does amp cycling mean?

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by MrPete, Sep 12, 2021.

  1. MrPete

    MrPete Member

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    Hi all,
    New to using Prolong reconditioning system.

    The instructions have a few gaps ;)

    The charger instructions assume you're doing the first charge (ie from a "normal" charge level.)

    I'm now doing my second charge, starting from a very-discharged level (around 160 volts.)

    Instead of a steady 0.355 amps (for 215 to 239 volts), the charger is ALL over the place. Rapidly shifting between values ranging from 0.002 to 0.996 amps.

    QUESTIONS (@jeff652 ??)
    * Is this normal, or indication of an issue?
    * At what voltage should it switch to a more normal charge pattern?

    THANKS!

    Pete
     
    #1 MrPete, Sep 12, 2021
    Last edited: Sep 12, 2021
  2. PriusCamper

    PriusCamper Senior Member

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    This is normal... I used to think it was programed to vary the amperage load based on feedback from the pack its charging, but a hardcore fan boy of Maxx Volts Hybrid Automotive Grid Charger Reconditioning Systems explained that Prolong used really low quality components and that what you're seeing is clipping from low quality charge signal. Here's the pro audio definition of clipping:

    "Clipping occurs when more power is required from an amplifier then it is able to deliver. Once the maximum amount of power supply voltage has been reached, it becomes impossible to amplify the incoming signal without compromising its form. This means that the signal is amplified but in a very distorted form." Clipping: how to prevent acoustic distortion | Teufel blog

    And while I don't know how accurate the fan boy was in his explanation, I'm fed up with poor quality products, as well as repair services from Prolong and won't be doing business with them again.
     
  3. MrPete

    MrPete Member

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    I know quite a bit about clipping. That's a Really Bad illustration. Clipping is quite simple: instead of a nice sine wave curve, the (audio) output signal gets flattened instead of peaking. (Think: mountain peak with the top cut off.)

    Thus, if the charger were actually "clipping from low quality charge signal", we'd see a constant value, not a value going to zero.

    Here's the reality I've now seen:
    * Somewhere between 200 and 211 volts, the charging current stabilizes at 0.355 amps
    * My guess: below that, the charger is simply being very cautious about heat and current, and is cycling the charge as pulses.

    Note: once the battery is in its normal range (210+?), as the voltage increases, the current remains constant. That means the charge power is constantly changing to match the battery pack voltage. (Power = Volts * Current.)

    This means the charger is easily capable of putting out all the charge power required. NO WAY is the charger incapable of putting out enough power, nor does it suffer from "clipping" the output. The effect I see is at LOW charging power, not high charging power.

    You're welcome to your own opinion about this or any other vendor. However, what you shared is quite obviously not factual.
     
    #3 MrPete, Sep 12, 2021
    Last edited: Sep 12, 2021
  4. MrPete

    MrPete Member

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    (I took a look at Maxx Volts. Their one recommended example tells me someone doesn't know what they're talking about. A 2012 standard Prius, charged to approx 130 volts.... and discharged to well below ten volts? Doesn't sound like a Prius. Even more significant: they accept no returns on purchased products, for any reason. Repairs but never a refund, period. Doesn't sound like a company confident about their products. Mostly, they seem to promote themselves by bashing non-existent downsides of unnamed competitors. )
     
  5. PriusCamper

    PriusCamper Senior Member

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    Yea, like I said that was the fan boys opinion... I think what we need is a way to measure the amps the Prolong charger is pumping out to confirm your theory. My personal thought is that the amp meter they use that goes down to a thousandth of a volt is visually stimulating, but not a design feature that varies the amperage load in any meaningful way. Sure would be great to finally figure it out!
     
  6. MrPete

    MrPete Member

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    Ummm... What they measure is whole volts (not thousandths), and amps down to mA (milli-Amps.) Not a big deal to measure that, really. Lots of such displays available, under $20 :)

    And by the way, speaking as an electrical engineer... designing a controlled current supply is not a big deal. Not sure why you would be so skeptical about this! I own an Opus BT-C3100 battery reconditioning device (for AAA to D cells) that allows exactly such constant-current control for four independent batteries.

    I can easily measure the power draw of the device: I own a high end Fluke meter, including an accurate non-contact AC amp-meter capability. So with a tweak of the power cord, I can measure power in. Not the same as power out, but if something is wayyy off, we'll know. :) -- I'll do that later today if I have the time.
     
  7. PriusCamper

    PriusCamper Senior Member

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    Yeah, that was a typo... Looking forward to seeing if your amp meter sees it different than prolong's...
     
  8. MrPete

    MrPete Member

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    I just got off the phone with Hybrid Automotive.
    The "amp cycling" is an artifact of the charging system electronics. Any time the target battery is more than about 50 volts below the charger voltage, the amps will cycle.

    It's still charging slowly. You just get a weird reading that's uncomfortable to watch.
     
  9. MrPete

    MrPete Member

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    Here's the data...

    DC to Battery
    239 Volts
    0.355 Amps
    84.8 Watts (V*Amps)

    AC to Charger
    121.2 VACrms
    1.5 Amps
    181.8 Watts (V*Amps)

    Both are stable.

    Mostly, what we learn from this is:
    * It takes over twice as much power to run the charger
    * (Not a surprise: a lot of energy goes into heat; and into removing the heat)
    * Yes the power level IS stable

    I'm sure that isn't particularly satisfying. However it is 100% real.

    (FWIW, it is very important and helpful that my meter is a "true rms" meter. It means it displace the AC volts in true rms values... which means that the exact same signal as DC would have that value in Amps)
     
  10. TMR-JWAP

    TMR-JWAP Senior Member

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    I received a brand new, in the box, Prolong Deluxe model as a partial trade for a battery job a few years ago. I used it a couple times to do some experiments. It was "mostly uncomfortable" for me to see this the first time, because it initially made me think it was broken. Then I realized it appeared to just be pulsing. Then, as voltage crept upward, it went rock steady. Never worried about it again. Figured it was just part of the programming for low voltage conditions. Glad you talked to them to get an accurate answer!
     
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  11. derickz

    derickz New Member

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    Do you have a discharger too? I am looking forward to seeing how is your result comes.
     
  12. MrPete

    MrPete Member

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    I do have a discharger. Ran through the three full cycles. Result: I have a few pretty awful modules in the middle of my pack.

    I ordered some replacements... and discovered they are better than dead but not by a lot :(

    SO:
    • I pulled the battery pack
    • Created a load using two halogen headlight bulbs (2x55 = 110W nominal at 12V)
    • Ran a test on every module for two minutes, and continued if it was already dropping quickly by then
    • Result: most modules only drop 0.3 to 0.4 volts (from mid-7's) in two minutes
    • Two modules dropped more than half a volt in a minute. Before minute two they dropped into the 5 1/2 volt range. Dead Cells.
    • One module was "marginal" -- dropped almost a volt in two minutes. I tested again... It too dropped into the basement soon thereafter.
    • Three of my cheap-purchased modules held on for over two minutes. Since we leave on a trip this weekend, I'm going to swap them in
    • Two cheap-purchased modules are junk. Returning.
    Hopefully, either:
    a) I can recondition the three purchased modules to be more effective
    or
    b) I can find better modules to purchase
    or
    c) (Not likely this year) I can play with rehydrating hahaha
     
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