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Hybrid Battery: recondition or replace?

Discussion in 'Prius v Care, Maintenance and Troubleshooting' started by PriusHead05, Mar 17, 2022.

  1. PriusHead05

    PriusHead05 Member

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    I have been on here before about my father's 2012 v, but the other day he noticed his hybrid battery was at two bars. It stayed there for at least two or three miles of driving before it would start to slowly charge back up. He has figured out what happens is 1.) when the car on but stationary or 2.) when he is driving below 35 mph through a neighborhood, the battery will drop down to two or three bars (normal so far) but then it takes a long time and a few miles before it starts to slowly charge back up. It has never taken that long nor that slow to recharge before. When my father's driving in a neighborhood at lower speeds, he has to try to either keep the motor or the regenerative brakes charging the battery so it doesn't drop down to two bars on the SOC.

    There are no codes. We did perform the two tests in the Dr. Prius app. The first test showed the was an imbalance in the lower voltages of Block #9. Then the life expectancy test stated, "Warning!! Battery overdrew power during test for more than 20 sec. accuracy was compromised. Battery has estimated 41.61% capacity left. It is in bad condition, but will still run." (It felt more like 10 seconds, not 20 seconds. I had to keep adjusting it to keep in the green area. Those who have done the test before will know what I mean.)

    Interesting thing though, is that it never occurred to me until yesterday that I have never seen the vent for the hybrid battery. After doing some research and finding it was underneath the seat, I found it, about 90% hidden underneath a piece of paper. I did notice in the test, that the battery did reach 107°F after about 15 mins of driving. I didn't hear the fan at that temperature even with my ear right next to the vent and the fan.


    Our main goal is to save the car, especially with the vehicle market today. The cold start rattle I have mentioned previously came back one or twice since the last time I mentioned it, but it's getting into the 80s here in Florida again, so we're not worried too much about that. That will be dealt with if or when it gets worse. Toyota already replaced the ABS pump/module under warranty. All other maintenance is up to date. It's not an oil burner. It has almost 144k mi. on it. What we're trying to figure out is, if the battery is a candidate for the Prolong charger or is it just better to replace the pack since the paper was in front of the vent?
     
    #1 PriusHead05, Mar 17, 2022
  2. rjparker

    rjparker Tu Humilde Sirviente

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    This is unnecessary. It is ok to see two bars under those conditions and it is normal to take several miles to recharge. Dr Prius is not definitive either, the car will code and give a hybrid error when the hybrid battery starts to go. Even then you may have months or a year. A prolong charger won't help much and is certainly not worth the cost. Battery chemistry has so many charge cycles and that is it. There is no magic reconditioning strategy. You often see used prolong chargers for sale. There is a Florida dealer selling new oem cells for $1300 right now which is the way to go when the time comes.

    The cold start rattle is the big concern. That could easily cost you $3,500-$7,500 for an engine.
     
    #2 rjparker, Mar 17, 2022
    Last edited: Mar 17, 2022
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  3. PriusHead05

    PriusHead05 Member

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    I see. When the cold start rattle happens, as far as we can tell, no coolant is being lost. We have heard about the EGR system and the head gasket, but what does the EGR have to do with the head gasket? How does cleaning or not cleaning the EGR affect how long the head gasket lasts and is there proof that it really works or is it just a theory?
     
    #3 PriusHead05, Mar 17, 2022
  4. bisco

    bisco cookie crumbler

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    as the egr clogs, more pressure is exerted on the head gasket. and these head gaskets have a weak point to begin with
     
    #4 bisco, Mar 17, 2022
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  5. bisco

    bisco cookie crumbler

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    it's not too soon to begin grid charging the battery if you want to get the most life out of it
     
    #5 bisco, Mar 17, 2022
  6. PriusHead05

    PriusHead05 Member

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    Is it worth it to clean the EGR or does it not matter since it already has started the cold start rattle? Also, is it worth it to fix the head gasket/motor or get a different Prius? If it's worth fixing, at what point do you need to fix it in order to not end up with a bent rod?
     
    #6 PriusHead05, Mar 17, 2022
  7. royrose

    royrose Senior Member

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    It is not certain that your head gasket is shot. You should clean the EGR system including the cooler and the EGR passages in the intake manifold, then see how it runs. If OK, then it is worth replacing the hybrid battery either now or when it fails.

    A lot of the cost vs benefit of keeping a vehicle with this many miles, especially a hybrid, is whether you can do maintenance yourself. Cleaning the EGR system is a pain IMO, but can be done at essentially no cost if you follow DIY videos.

    BTW, did your dad have spark plugs replaced which is normally replaced at 120K? If not doing those at the same time as cleaning the EGR system would be an efficient use of time because you have to take off some stuff to get at both.
     
    #7 royrose, Mar 17, 2022
    Last edited: Mar 17, 2022
  8. PriusHead05

    PriusHead05 Member

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    The EGR valve was replaced by Toyota at 80k before he bought it. We replaced the spark plugs ourselves at 140k. The plugs looked very good for 140k. Nothing abnormal about them. I haven't watched a video on how to do the EGR cleaning yet, but it sounds like a big and difficult job. I will have to see how it's done next. We're not afraid of big jobs, but we don't want to start something and halfway into the job, we find out we don't have to tools or the resources capable to complete the job.
     
    #8 PriusHead05, Mar 17, 2022
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  9. Mendel Leisk

    Mendel Leisk Senior Member

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    My understanding: the engineers are counting on a free-flowing EGR system to keep combustion chamber temps in a certain range. The system slowly but surely clogs up with carbon. Usually the first bit to totally clog is the capillary EGR passage in the intake manifold at cylinder one.

    The preponderance of head gasket failure reports are at cylinder one, typically the adjoining wall between cylinders one and two. The head gasket failures are happening anywhere between 125K and 200K, and that's also around the time the EGR fully clogs.

    How many miles on yours btw?
     
    #9 Mendel Leisk, Mar 17, 2022
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  10. PriusHead05

    PriusHead05 Member

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    #10 PriusHead05, Mar 17, 2022
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  11. bisco

    bisco cookie crumbler

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    yes, you should clean the entire circuit. see @NutzAboutBolts youtube video.

    if the head gasket blows someday, it's not a clear cut decision, it's a cost benefit analysis.
     
    #11 bisco, Mar 17, 2022
  12. bisco

    bisco cookie crumbler

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    as soon as the engine starts rumbling consistently or you get trouble lights, you don't want to drive it anymore. if it is the head gasket, loss of coolant can lead to a blown engine.
     
    #12 bisco, Mar 17, 2022
  13. vvillovv

    vvillovv Senior Member

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    If you're on the west coast or central FL you might want to bring the car to Tampa Hybrids for a full diagnostic using techstream. The results from the techstream scan will get you much better answers here.

    edit opps sorry @douglasjre I posted before I read yours.
     
    #13 vvillovv, Mar 18, 2022
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  14. Tim Jones

    Tim Jones Senior Member

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    You need to examine the coolant reservoir and make absolutely sure it isn't low...... mark it with tape and keep checking it or trade it in.................... other bad things are just around the corner
     
    #14 Tim Jones, Mar 20, 2022
  15. Paul Slomba

    Paul Slomba Junior Member

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    I am in Florida, currently looking to buy a new oem battery. My prius has 315k original battery. Still going but the battery doesn't hold a charge very long. Which dealer is selling for this price? The best price I could find was from Melbourne toyota for about $2000
     
    #15 Paul Slomba, Oct 15, 2022
  16. rjparker

    rjparker Tu Humilde Sirviente

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    You have reduced capacity. It will probably hold the available charge for weeks or months if you don't use it. But with reduced capacity you may get to a stop light charged up only to have it discharge enough to start the engine before the light turns green.

    The reduced price was seven months ago. Two points: That price shows you where the dealer wholesale price was or is and a new set of cells will last another ten years versus months. There are aftermarket new cells as well. If planned and timed properly, I would get the lithium upgrade kit.
     
    #16 rjparker, Oct 15, 2022
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  17. johnHRP

    johnHRP Active Member

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    $2000 is a good price and go for it if the car is in good condition, no bad rust, bad suspension,etc. Never buy aftermarket battery, they are not tested for fire, and all kind of safety features why early Prius use NiMh battery, not Li ion that are often cought on fire.
     
    #17 johnHRP, Apr 1, 2023
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