HCH-II Recalibrations (Recal). What are they ?

Discussion in 'Honda Hybrids' started by msantos, Aug 6, 2009.


Have you ever had a re-calibration of the SoC on your HCH-II ?

  1. What is a recalibration?

  2. Never. At least not yet.

  3. Yes, I get them once in a while (at most 1-2 per month)

  4. Yes, I get them at least once a week

  5. Yes, I get them once every day

  6. Heck yes... I get a recal during every commute

  7. Heck yes... I get a recal during every commute and I also have the IMA light ON

    0 vote(s)
  1. cheezmo1

    cheezmo1 New Member

    I would like to chime in here. I too had the exact same issues and same response from Honda as Mainiax.
    My experiences are somewhat documented on another site(hope i dont get in trouble):

    When i read replies in this thread and other threads similar like mine, some poeple come across as helpful but don't believe our situation. This is truely a serious issue. I asked Honda to send an Engineer and test my car because something is seriously wrong and their tests don't show it. They refused. My experience has made me not want to buy a honda, ever, and my wife, who picked the Civic over the Prius, feels really bad.
    I had my battery replaced, but I still don't get gas mileage close to my previous 3 years of owning the car. I loved seeing 50-55mpg, now I barely get 40-45(even with a new battery) I think something is seriously flawed and Honda is refusing to even look at cars like Mainiax and mine.
    Deep down, i didnt want my battery replaced because I wanted to take it to a Toyota dealership and have them use my car as a test car against the Prius so no one would buy a "good" Civic Hybrid like mine, lol. :p But what is done is done, and now on other sites I see more stories like ours which scares me. I think poeple before us shrug it off and got rid of the car, but we stood and fought. Once you see the video you hopefully will beileve something is going on.
    I figured out that it started happening after i got my oil changed in Feb of 2010 (computer flash), and also when I added two child car seats in the back. That's all I know.
  2. matmanaz2000

    matmanaz2000 New Member

    I live in AZ. I purchased my 2008 Civic Hybrid about 3 months ago and I experience the "battery dump" two or more times a day. I have been reading this is heat related and my commute is usually in 105 to 112 degrees outside.

    The AC works GREAT compared to other cars I have had, and it is ALWAYS on 68 degrees! So far the MPG had stayed between 29 and 35, depending on how much highway driving I am doing.

    The funny part is I am happy with this, considering the temperatures and AC requirements! I have had other small, lightweight cars. My last car was a Smart... The Civic Hybrid is getting better MPG then the Smart was.

    I am also not conservative about driving style, but the charge/assist meter is mezmorizing, seems to keep my foot light.

    I usually have 1-5 bars. I did see 7 and 8 bars once on a cloudy, rainy day when it was about 85 outside and I was driving back from the lake. That drive is about 10 miles of gradual downhill driving. Otherwise it stays in the 3-5 bar range most of the time.

    I could only DREAM of 40+ MPG! But like I said. I am happy with the car considering the conditions I drive in.

    The only time I have been a little frusterated is when it drops to 1 bar and I need to accellerate into traffic on the freeway.. That is a little stressful...

    I don't have any idea if I should have the software, etc checked... Or be concerned. I would like to see better MPG, but I also want to be realistic. I am hoping when the temperatures cool down I will see more consistent battery monitoring and a higher maintained charge level. Not to mention some 40+ MPG experiences. But I won't expect that until I can stop using the A/C.

  3. hunter44102

    hunter44102 Well-Known Member

    I suggest getting the latest software update from your honda dealer. It should resolve the 1 bar power issue (it did for me after the update). The update is free

    Since you are running A/C almost all the time, you will have a hard time getting much above 40MPG but even 35 is better than most cars with A/C turned on

    I have been to Arizona a few times. The summer heat is crazy. I would suggest trying to always park in the shade, or doing the solar panel battery cooling mod that MSantos did in a different thread.

    If the car is sitting in an uncovered lot, the battery will be cooking even if the car is not running. Airflow would keep the battery in better shape
  4. msantos

    msantos Eco Accelerometrist

    Hi matmanaz2000;

    Welcome to CleanMPG!!!

    The latest batch of software updates is specifically designed for your circumstances. I would urge you to consider visiting your dealer and have them applied without much delay.

    I would also suggest you hang around CleanMPG for a bit and read up on the numerous tips we have to offer - especially those concerning air conditioning use as well as other strategies for managing heat while significantly improving your MPG's. ;)


  5. cswee1932

    cswee1932 Well-Known Member

    Reaching out to Msantos,

    So I've had my HCHII for about 5 months now and I absolutely love it as much as I did the day I picked it up....

    Since it's gotten a lot colder here the last month or so I've been experiencing racals daily, sometimes twice in my usual 13 miles commute, morning and afternoon.

    I figured since it's under warranty it couldn't hurt to pop into Honda, so I scheduled an appointment, and the tech took it out for a spin and said all checks out OK. They even gave me a slip with a graph on it and a battery reading, which I've since lost, dummy :)

    They basically told me what you have stated, saying that the cold weather can have effects on the pack, but 2 a trip seems excessive doesn't it?

    We'll see how it goes when it gets warmer.

  6. msantos

    msantos Eco Accelerometrist

    Hi Chris;

    With the latest software installed? No, two "recalibration" per 10-15 mile trip is not a bad sign anymore especially when under extreme weather scenarios (too hot or too cold).

    First and foremost, I would like to mention one very important distinction between the Pre June 2010 software and all updates made available since that date:

    - Any recalibration events that occurred in Pre-June 2010 software were instrumented and regarded as actual anomalies detected in the operation of the hybrid system.
    - Depending on the state of the battery pack, the June 2010 software updates will trigger a forced regeneration process that actually uses uses the recalibration routine. The software update simply causes a few things (inhibit auto-stops, etc) including an eventual invalidation of the SoC to happen sooner and more frequently. These recalibrations are NOT the result of a fault detection (as in Pre-June 2010) but rather the result of the new thresholds set by the software update. This now qualifies as normal operation until an IMA light appears.

    Unfortunately, many techs do not know the difference between the two recalibration events and many owners have almost no chance to learn what it really means. But fear not, here it is in a nutshell:

    - If we got the June 2010 updates properly applied then the invalidation from 6-5 bars of SoC to just 2 bars is the NEW forced regen procedure. The older OEM forced regen routine that got triggered when SoC reaches 4 bars has been almost suppressed in favor of the pseudo-recalibration routine.


  7. Kacey Green

    Kacey Green Well-Known Member

    Manuel, did any updates also include never turning off the IMA fan? Mine now only cuts off 5-30 sec after I key off the car, even in near freezing weather.
  8. msantos

    msantos Eco Accelerometrist

    Hi Kacey;

    Yes. It is an ABSOLUTE MUST since Honda now wants the SoC to remain as high as possible most of the time (the same thing many of us always suggested over the years ;) ) and as you know, prolonged regenerative sessions always lead to increased heat generation... and heat is a perennial enemy of any pack especially those produced with cylindrical NiMH cells.

    Other things that have changed with the newer software:
    - Increased levels of engine load to promote sub 1-bar regens
    - Reduced auto-stop duration
    - Auto-stops now tend to occur primarily when SoC is at 6+ bars
    - Operational EV-Glide window severely reduced


  9. fileaudio

    fileaudio heavy foot ultramegamiler

    i think its not fair for such a good contribuitor to this forum that has helped a lot of people here , that the last post in this thread was made by him/// this thread is very interesting and has bringed some light to the hchII, myself its been using tips and tricks.... my ima battery was replaced under warranty without IMA ligh on now on 2014, I guess i was lucky, well the car its been doing great with 52 mpg combined and mostly city, my battery never never has going down to less than 4 white bars of battery on soc/ so I never have seen 3 bars in the display, maybe its due to the software up they made this is normal? when the white bars are in 4 bars the car start charging 2 green bars,,can be that called a recal???? then when its on 5 white bars regen stops and autostop and asst comeback... this is supposed to be that way???
  10. hunter44102

    hunter44102 Well-Known Member

    2 bars charging is not a re-cal. You've just reached a lower charge that initiated regen. The battery -will- lose its charge especially during take off from 0MPH or passing where assist is used a lot. So this is normal charging.

    A re-cal is more when you go from full assist bars to green charging within a matter of a minute or two. Basically the car thought the battery was full, and by putting a load on the battery (assist), the voltage dropped suddenly and forced the re-cal routing.

    Its caused by a 'memory affect' of NiMH batteries - its also called a 'voltage depression' effect.

    In my opinion, the HCHII computer does not do what should be done occasionally to NiMH batteries of all types - from greenbatteries.com FAQ:

    "To completely eliminate the possibility of NiMH batteries suffering any voltage depletion effect manufacturers recommend an occasional, complete discharge of NiMH batteries followed by a full recharge."

    This is why I have always been able to restore my HCHII battery to full function by draining it with light bulbs down to 100 volts and recharging to full (about 180 volts). I am now at 140k miles on the original battery. I have done the cycle twice on the battery.

    However, you don't want to go crazy with this. Just do it once every year (OR if you start getting recals). The reason you don't want to go nuts with this is because NiMH batteries can only be cycled like 500+ times when you do a full charge cycle.
  11. fileaudio

    fileaudio heavy foot ultramegamiler

    Thanks for the response Harold it was helpful I was trying to understand how does it works.... I must say that the only time my white bars was at 3 bars WAs with air conditioning on and it was just once. So after installed the new ima battery under warranty I never was on 2 bars or 1 maybe the new update is more gently with the pack.. Last week they changed the DC converter I noticed 3 or 4mpg less in lost.. I was on 53 mpg I'm on 48 aprox.. Maybe they dude another update
  12. S Keith

    S Keith Well-Known Member

    Updated information:

    Given the above is 6 years old, here's what some recent testing showed me. it IS significant given the instrumented range.

    Forced recals overcharge good sticks and undercharge bad sticks. This accelerates the deterioration of the good sticks. 100% car SoC = 80% full SoC. As-removed testing showed the "good" sticks (the ones with well balanced cells and good capacity) were testing at 90-95% of their rated capacity instead of 80% while the weakest sticks (those with reduced capacity or imbalanced cells) were VASTLY reduced (many less than 50% capacity due to 1-2 bad cells/stick).

    Bottom line. Forced regens accelerate pack deterioration. Period.

    Regular occurrences of recals should be a signal to begin a process of periodic grid charging and deep discharging.

  13. Mendel Leisk

    Mendel Leisk 2010 Prius (CAN Touring) Staff Member

    This is depressing. :)

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