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Gen 4 Aux Battery in Short Supply

Discussion in 'Gen 4 Prius Main Forum' started by William Redoubt, Mar 31, 2019.

  1. William Redoubt

    William Redoubt Senior Member

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    My 2016 Two has devoured its second 12 Volt aux battery at 88,500 miles. Local dealer verified the battery is dead (replaced under warranty at 35,500 miles). The original was replaced with an 84-month warranty (full no-cost replacement if it fails within 24 months). Dealer states battery is back ordered over 30 days. Offered loaner car. Comments? The retail cost of the battery is $289.
     
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  2. krmcg

    krmcg Lowered Blizzard Pearl Beauty

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    My battery was also replaced at just short of 36,000 miles under warranty. I guess I will have to really watch it when it gets close to the 2 year guarantee date...
     
  3. pilotgrrl

    pilotgrrl Senior Member

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    I'm going to get my battery checked when I take it in for an oil change and the recall service. It will be 3 years old at the end of June.

    MHA-L29 using PriusChat mobile app
     
  4. ekpolk

    ekpolk What could possibly...

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    If you want to (are willing to) go aftermarket, you might consider this option:[​IMG]

    It's a Group 140R size, not the most common out there, but findable. Is fitted in cars like the Chevy Spark, etc. IIRC.

    But note: there's a consistent anomaly in the parts finder databases the online sellers all use. It will NOT show any Group 140R as being a match for the Gen-4 Prius, even though dimensionally and by performance parameters, it is essentially an exact match.

    Just something to consider. Even if Toyota won't "outsource" and buy you one for wty replacement, spending the $138 might be worth it just to get your own car back. . . Good luck with it.
     
  5. bisco

    bisco cookie crumbler

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    couple comments: 12v's are not lasting well in gen 4 and prime. it was supposed to be a bigger more robust battery.
    there have been many complaints of back order situation.

    something is wrong with design of the electronics and toyota has not addressed it to my knowledge.

    short battery supply is probably due to the number of replacements, odd size (again) and lack of supply due to the odd size.

    lastly, it's a great dealer who will give you a 30 day loaner over a 12v battery.
     
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  6. Mendel Leisk

    Mendel Leisk Senior Member

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    Two batteries already on a 2016? Anything odd about your driving, infrequent use? Any accessories that run while the car's off? Or?
     
  7. bisco

    bisco cookie crumbler

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    infrequent use = 4,000 mile trip once a month?
     
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  8. mark27lim

    mark27lim Active Member

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    my stock original battery had 6 water caps which needed to be topped up with distilled water when low. i discovered this only when it was too late and the water was way low. by then the battery was unserviceable and had lasted me almost 2 years. not sure if the usa version uses maintenance free battery for stock. mine was a japan imported prius.
     
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  9. tucatz

    tucatz Active Member

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    Doesn’t sound right. I’ve owned 9 Toyota’s(3 prius’) and Honda’s and have never replaced the 12v battery. I left my 1992 civic parked for 18 months while away at school. It started right up!
     
  10. sam spade 2

    sam spade 2 Senior Member

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    Even if the OEM battery is not AGM, your replacement certainly SHOULD BE.
    The few extra dollars is well worth it.
     
  11. CooCooCaChoo

    CooCooCaChoo Active Member

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    The problem is that trying to find an AGM battery in size 140R is impossible right now.
     
  12. alanclarkeau

    alanclarkeau Senior Member

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    But it's not an AGM battery that TOYOTA uses.
     
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  13. sam spade 2

    sam spade 2 Senior Member

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    Which was a REALLY bad call, in my opinion.

    So MANY vehicles have come with maintenance free batteries for SO long now that going back almost guarantees that it won't be given the periodic attention that it needs. That might be true even if you go to a dealership for your routine maintenance.
     
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  14. ekpolk

    ekpolk What could possibly...

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    Technically, yes. That said, I'm considering an Odyssey PC1200T. It is AGM. It's slightly smaller in all three dimensions than the OEM 12v. It exceeds or outperforms the OEM in all performance parameters. It DOES NOT have the extended "lip" at the base that engages with the Prius battery tray. I'm looking at strap or bracket options, or using epoxy to fashion my own extended base so it will fit properly. And yes, it's a tad bit more expensive than the NAPA lead acid option, but seems competitive with dealer price options. [​IMG]
     
  15. alanclarkeau

    alanclarkeau Senior Member

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    Has your battery failed already? I'd have thought that the warranty would be current on your OEM one.
     
  16. bisco

    bisco cookie crumbler

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    dealers don't have batteries to fill warranty claims
     
  17. ekpolk

    ekpolk What could possibly...

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    No, mine's still "good" -- for now, but I'm keeping a close eye on it. The "problem" is that my Scangauge most often reports voltages from 11.6 - 11.9 if I power up to the Accessory or ON modes (versus READY mode). In a conventional car, this would be a strong indicator that the 12v batt was on its way out. But of course, with cranking loads never challenging the battery, who knows. . . I am seeing no other indications of trouble. I'm just doing my homework in advance so that if I need to act, I'll be prepared. As for the wty, I really haven't decided whether to go that route, or just bite the bullet and get a top quality AGM at my own expense. I'm really not interested in playing the "serial replacements" game with a 12v design that appears to be somewhat troubled in this application. Also, frankly, I just enjoy "overkilling" things with my machines -- especially my car. I mean, I own a Prius fer cryin' out loud -- that's a tad bit extreme in and of itself! ;) :cool:

    EDIT: you may recall from earlier discussion that my car was a dealership "orphan" that sat for a year, dealer swapped twice before I bought it. Perhaps not surprisingly, it already had a replacement 12v instead of the factory battery. I have zero knowledge of the circumstances or timing of the replacement. The car had exactly 100 miles on the ODO when I took delivery.
     
    #17 ekpolk, Apr 9, 2019
    Last edited: Apr 9, 2019
  18. Mendel Leisk

    Mendel Leisk Senior Member

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    Traditionally Prius and AGM go hand-in-hand, and it's hard to shake the notion, but with fourth gen battery in the engine bay: yeah why AGM?

    I don't think original battery is AGM?

    Plugging in a 2016 Prius at Canadian Tire, it's showing no battery options. Hmm.

    Argh! At the least, check the voltage with the car off, with a digital multimeter. Or better, directly at the posts with something like Solar BA5.

    And if you really want to keep a close eye on it, if practical for your parking situation: get a smart charger, hook it up when the car has multi-day down time.
     
  19. bisco

    bisco cookie crumbler

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    a good lead acid battery, with a properly designed charging system should last 10 years. maybe less in the heat, idk.
    i have two that are 15 years old and still strong. one in a rarely driven truck, and the other in a generator with float charger.
     
  20. ekpolk

    ekpolk What could possibly...

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    The OEM battery is not AGM, at least from all the info I have seen, and someone replaced the missing OE battery from my car with a standard, non-AGM battery.

    For me, it's a purely practical problem. For the next few months, I'm doing training 500+ miles from my house -- and all my tools. This leads me to the issue of the quality of the info I'm seeing on the Scangauge. There are a couple sources of possible error there; calibrations, both in the car and the SG itself, whether a reading taken even a split-second after going from OFF to ON is valid, and so forth. As long as the car is starting/booting up OK, I'm not going to do anything. Once I next get home (probably three weeks at this point), I'll be taking some new measurements, as you suggest, with my quality multi-meter. THEN I should have a better picture of what's going on, if anything.
     
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