2012 Camry Hybrid Prolong Reconditioning Results

Discussion in 'Toyota Hybrids and EVs' started by Cyvan, Jan 15, 2020.

  1. Cyvan

    Cyvan Junior Member

    Jul 7, 2018
    Other Hybrid
    Since its relatively cool now I decided do my first full reconditioning with my Prolong kit. I have a 2012 JDM Spec Camry Hybrid with 90k miles on it.
    I started Sunday evening by driving down a local mountain road to bring SoC to 75% and did three full fill and balances and 2 discharges to finish Wednesday afternoon.

    Before I started I ran a battery test using Hybrid Assistant with a 10-11amp draw:

    My main reason for doing this is that I was noticing that after around SoC 45% the battery would drain faster and even when the engine kicked in at 40% it would dip as low as 34% before it started coming back up. This was getting worse because initially it would only dip to 38%.

    My parameters are still well within acceptable ranges but those dips had me concerned. Notice how the voltage delta (gray area) increased as SoC drops.

    Couple things I noticed:
    • 1st fill topped out at 289v after 13hrs.
    • 2nd fill peaked at 288 after 15hrs but , over the next 6 hrs dropped down to 284v?? This was now during the day so I don't know if it was due to the higher ambient temperature. So I stopped there and started discharging.
    • 3rd fill took 18hrs and topped out at 286v.
    I let it rest for about 2hrs (I remember that story of the person who wasn't patient and started it too quickly :D) and started it up. Drove it around for a bit and definitely noticed a difference. Did another test and here was the result:

    Delta is now more stable throughout. However I now notice a slight increase in the delta during charging?
    Unfortunately the scales of these 2 graphs are different so I exported the data and tried to combine it in one graph:
    Orange/Yellow is before(BMax, BMin, BSoc), Blue is after. The Purple Line is SoC After.

    A couple things stand out:
    • Both started at 60 SoC and ended at 50 but now its starting and finishing at lower voltages than before. One thing to note: The post-test actually started at 62% SoC. I just discarded the values before 60 SOC, so I don't know if that had any impact. But is this normal?
    • Notice the precipitous falloff in the Before SOC just prior to and even after the engine started. That's not there now. But they both charge at the same rate.
    • The gradient seems to be much shallower now and It's lasting longer, ( by roughly a minute ) before the engine kicks in.
    Its still early days so I'll run another test in about a week to see if these improvements hold. I'm curious about the voltage changes though. Hopefully some of the experts like @2k1Toaster and @ericbecky can chime in :D
    #1 Cyvan, Jan 15, 2020
    Last edited: Jan 15, 2020
    Raytheeagle likes this.
  2. Raytheeagle

    Raytheeagle Senior Member

    Jul 1, 2016
    Bay Area, California
    2019 Prius Prime
    Prime Plus
    Also worth including @jeff652 with his thoughts;).

    He's usually interested in the results and will offer his thoughts when he's not beating the streets(y).
    Cyvan likes this.