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Chasing better MPG, 2nd phase

Discussion in 'Gen 2 Prius Main Forum' started by George W, Sep 6, 2018.

  1. George W

    George W Active Member

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    I'm in my 4th month of ownership of a 2008 Touring Prius, with 130K miles. The initial economy number was 35 mpg, and several helpful members suggest a tune-up. I've replaced Tires, Spark plugs, Air Filter, Cabin Air Filter, and 12V battery. I've cleaned MAS, Throttle body, added Fuel Injector cleaner, and increased tire pressure slightly.

    This resulted in an increase to 40 mpg. Better, but not good enough. Again, helpful members have suggested two most-likely possibilities, wheel alignment or aging HV battery. I'd like to thank 'edthefox5' for his helpful referral to hybridautomotive.com . It was there I learned about the Prolong Charger system, and that there is an authorized Installer of this system in my city, Hybrid Car Repairs.

    I took the Prius to Hybrid Car Repairs today, asking them to look at everything. After some time, they couldn't really find anything wrong, except that the HV battery was taking a long time to accept a charge. They said that the ICE was kept running longer. Getting late in the business day, I had to make an appointment to return, so they can disassemble the HV battery to inspect for corrosion. They don't believe the pack is bad, yet, but they do think corrosion is causing resistance to normal charging.

    This car was sold, and driven in Southwest Texas. Heat and humidity have been constant through-out its tenure. They took me into their shop, and showed me some 'scarred' ring tabs from another customer's battery pack. Sure enough, the copper has serious surface corrosion. It was easy to see why that pack had issues.

    Very nice people at Hybrid Car Repairs. They didn't even charge me for the 2 hours spent checking the car over. I asked them to write up a bill, but the service manage said he'd catch me on the backside.

    I'll update next week on what they find. Thanks to everyone on my other threads who have assisted with this low-mpg issue. Have a great day.
     
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  2. kens97uber171

    kens97uber171 Active Member

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    Seems like low miles.. but that may be the issue.
    I've got an 08 with 246,000 and battery capacity tests at 55% using an app I have..
    Corrosion could definitely effect the battery.
    Bear in mind.. getting to the pack and removing it is NOT that difficult.
    Maybe 30-40 min.
    You can easily pull the bussbars off and clean them yourself...
    You could probably do that without removing the battery.. just pulling the shell of the top..
    Follow all Safety procedure while doing it. But it's not that hard.
    You will need a 10mm, 12mm,14mm. I think that's it...


    Posted via the PriusChat mobile app.
     
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  3. PriusCamper

    PriusCamper Senior Member

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    55% capacity is normal at your battery's age and brilliant that Toyota designed a battery pack to go below 50% capacity before failing. If you decide to do it before it's to late, you'll be amazed at what battery reconditioning (aka 3-4 increasingly deeper discharges after 100% recharge) does to make your ancient battery pack near as good as new as far as your app test is concerned.
     
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  4. kens97uber171

    kens97uber171 Active Member

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    What's the best way to do that? Do a deep reconditioning?? Any suggestions would be great.. thx

    Posted via the PriusChat mobile app.
     
  5. jerrymildred

    jerrymildred Senior Member

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  6. Lucifer

    Lucifer Senior Member

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    Well, you can readjust the band aid but replacing the battery with a new factory installed traction unit would be five years of great mileage, so 3,000$ For a new unit vs ?
     
  7. bisco

    bisco cookie crumbler

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    start with the corrosion, see what happens, then move on to the reconditioning.
     
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  8. PriusCamper

    PriusCamper Senior Member

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    Your message may be appropriate for a car with warning codes and a failed module. But what you're parroting about Battery reconditioning being a "band aid" is completely false. The OP's vehicle is running normally and per the title of the post, this is not a repair issue, this a way to slightly improve MPGs and greatly improve Battery pack longevity.

    I'm so sick and tired of so many garbage comments trying to throw the baby out with the bathwater. And yes everyone wants to buy brand new shiny instead of taking care of what already serves them, but this desire is destroying the whole planet and we need to shutup with all the hyper-consumption advocacy and start living within our means, not beyond them.
     
  9. DLC82SV

    DLC82SV Member

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    Amen brother!

    Posted via the PriusChat mobile app.
     
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  10. Lucifer

    Lucifer Senior Member

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    Let me repete, it’s an 8 year old 12v and an 8 year old+- traction, it makes me sick to see people waste money trying to rebuild failed batteries, every year, over and over, “ad nauseam”, if you don’t like the fact that batteries fail, think again.
     
  11. PriusCamper

    PriusCamper Senior Member

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    There are a couple different ways to answer this question... But first you have to decide if you like cheap or free with the cost being lots of your own hours developing a new skill that your friends and family will one day greatly benefit from.

    Or if you don't have much time or desire to develop a skill, but have lots of money to spend you can go the route most people go on Prius Chat by buying a consumer product via: Prolong® Battery Systems FAQ – Hybrid Automotive

    Regardless of what you decide, read thru that hybridautomtive / Prolong link above to get a general sense / overview of what proper battery care is all about.

    If you want to go the free / low cost route you will need your two headlamps from your Prius, a multi-tester / volt meter and a smart charger at about $38 that are commonly sold on Ebay, as well as at Remote Control Toys / RC stores. One of the best chargers in my opinion is the full size version of the IMAX B6 AC V2 because it chargers all different types and sizes of batteries, so your charger will have other uses beyond reconditioning your Hybrid pack.

    Next step is to pull out your hybrid battery following the common safety instructions/tutorials on YouTube and then unbolt the bus bars that connect all 28 of the battery modules together. As @bisco says, you can start just by using vinegar to clean the corrosion caused by miniscule amounts of normal leakage from the modules. Sometimes this corrosion, especially on the voltage sensors connections can cause error codes in the car.

    Next step is to hook those two headlamps up to a module with your multi-tester attached and drain the module down to 6.5 volts, then charge it with your smart charger, then drain the module down to 6 volts then charge it, then drain it down below 6 volts and recharge again. Be very careful with the last discharge because it your drain the battery down to 0 volts polarity might reverse and the battery will be no good anymore.

    Granted, doing this charge and discharge 3 times on all 28 modules is time consuming, but if you like to design systems that get faster and more efficient every time this is a great challenge. First time I did the first round of discharge and recharge it took 2 days. But second time it only took a day. Third time I did it and had multiple chargers and completed the 3rd round of discharge and recharge in 8 hours.

    The more you do it, the faster it gets.

    In the next month or so I'll be posting photos of a system I'm building that costs less than $150 and can do one round of discharge and recharge of 28 modules in less than 4 hours. Compare that to the expensive Prolong system that may be easier / less labor intensive to use, but can take more then 24 hours to do a single discharge and recharge.

    Most importantly, make a spread sheet of all your data / track of the amount of time it takes for each module to discharge and recharge. This will be valuable information in the future if you ever have to do additional diagnostic work, etc..

    Or you can just forget about all this stuff till the battery needs a new module and revisit it then... Quite frankly, the best way to improve mpg is Low Rolling Resistance tires pumped above 45 PSI.
     
    #11 PriusCamper, Sep 7, 2018
    Last edited: Sep 7, 2018
  12. PriusCamper

    PriusCamper Senior Member

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    Stop being so clueless

    WE ARE NOT TALKING ABOUT A FAILED BATTERY!!

    WE ARE NOT TALKING ABOUT REBUILDING A FAILED BATTERY!!

    We are talking about basic science of NiMH batteries which periodically need reconditioning!!

    Please stop making yourself look so dense and pay attention to what we are actually talking about.

    And if you want something to feel sick about, think about all the times you went out and bought something brand new to replace something old that was still functioning perfectly. Seriously, people who are obsessed with replacing stuff before it's worn out think the same way heroin addicts think... STOP IT!!! Your insatiable consumer appetite is suicidal in the way it's depleting the resources of the whole planet so rapidly.
     
    #12 PriusCamper, Sep 7, 2018
    Last edited: Sep 7, 2018
  13. George W

    George W Active Member

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    I wondered about this. The max psi for the 16" tires is 51, and I have initially increased from the recommended 35, to 42. The ride isn't too bouncy, yet.

    I am a DIY sort of person, but do not have the space and physical ability to manhandle the HV battery around. I keep thinking that there should be some mini shop crane designed by a hobbyist that exists in the Prius circles.
     
  14. PriusCamper

    PriusCamper Senior Member

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    Go to a Home depot and pick up an 80 pound bag of concrete... If you can put that in and pull it out of your car again, that's about what you're lifting when you lift the battery out.

    As for tire pressure I recommend adding a pound or two PSI at a time until you start to lose traction and then back it off... I did 51 psi back when I was first trying to figure it out and it was way too sketchy for my tastes...

    Also be careful who you mention tire pressure to... Tire stores may refuse service if you bring it in with crazy high PSI and in general people will treat you like you're crazy... The Prius chat negativity team will come down hard on you for going above 35 PSI with claims about being a threat to the safety of people you share the road with, uneven tire wear and on and on and on. Best to keep a low profile when it comes to tire pressure experiments.

    If you do get in a situation with someone about being above PSI, you could quote the Hunter S Thompson book Fear and Loathing in Las Vegas where they were so high they were convinced that the best ride was 80 PSI.
     
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  15. Mendel Leisk

    Mendel Leisk Senior Member

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    Torque for the bus bar nuts is 48 inch pounds (4 foot pounds): it would be good to have a suitable torque wrench, typically that'd be a 1/4" drive. Get a set of adapters too, so you can connect 3/8" sockets, for example.

    I've attached 2nd gen Repair Manual info.
     

    Attached Files:

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  16. Mendel Leisk

    Mendel Leisk Senior Member

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    Noticed this on my desk:

    IMG_9334.JPG
     
  17. DLC82SV

    DLC82SV Member

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    We can't stop here... This is bat country!

    Posted via the PriusChat mobile app.
     
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  18. George W

    George W Active Member

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    You give me an idea for a fulcrum that would be cheaper than a shop lift, and I can reuse all the parts for something else. THANKS!
    I did purchase a torque wrench for replacing the spark plugs. It's rated 10 - 150 foot pounds. Looks like I'll be getting another.
     
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  19. Mendel Leisk

    Mendel Leisk Senior Member

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    Yeah it's good to have a torque wrench where the value you want is not near the bottom (or top limit), they're less accurate there (according to a sales rep at Sears, many years back). I can see that. I've now got a 1/2", 3/8" and 1/4": I'm READY.
     
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  20. The Electric Me

    The Electric Me Go Speed Go!

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    My specific feeling?
    In other threads, where people have undeniably failing Hybrid Batteries, that are throwing codes and have been confirmed as failing, I have more than once suggested the person simply replace with a new OEM Hybrid Battery.

    So I'm NOT against that, as the answer to the problem.

    However, in this specific scenario? As presented? The Battery is not throwing codes or outwardly failing. The OP simply wants to try to improve the MPG.
    I think little or nothing except some time, and some lesser investment gets lost by trying to modestly recondition the battery. It may be at a point where cleaning up corrosion really improves the battery and could give the OP significant MPG improvement AND several years of further service.

    Since the battery is not leaving the OP stranded, or not starting and doesn't appear to be a danger in operation? At this point? The OP seems to have found an independent Hybrid shop that is treating him fairly and offering good advice.

    I'm NOT much of a D.I.Y. person, so I might just keep it simple and see what they suggest. Since dealing with a Hybrid Battery can be dangerous, I also by default really never advocate for a lot of D.I.Y. work. I know that varies with owners, experience and desire.
    But at this point, it seems premature to be advocating for a totally new Hybrid Battery.

    I don't throw the milk out because it is close to the expiration date. I drink it until it's gone.