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2024 PP XSE 12v aux battery warranty replacement by toyota dealership

Discussion in 'Gen 5 Prius Technical Discussion' started by RandyPete, Sep 20, 2024.

  1. RandyPete

    RandyPete Member

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    My 12v battery in my 2024 Prius Prime XSE (car purchased in Dec 2023) was replaced under warranty last month (Aug 2024).
    1) The original battery installed at toyota factory is pictured below.
    2) The replacement battery replaced at a Toyota dealership under warranty is pictured below.
    The battery sizes are compatable for fit.
    The H2 venting of the two batteries are identical for installation inside the vehicle passenger space.
    The battery Specs, capacity are not identical.
    The replacement battery is branded Toyota True Start Battery
    Distributed by Toyora Motor Sales USA has a higher CCA rating (470 CCA) than the original ( 285 CCA).

    My experience was that the original battery dropped to 12.3v at rest after a few days in the driveway.
    My experience is that the replacement battery drops to no less then 12.5v after a few days in the driveway (I have not seen voltage at rest less than 12.5 volts with the replacement battery).

    I believe that a resting voltage of 12.3v or less for an extended period of time causes accelerated sulfation of the battery '-' plates detramental to battery performance.

    I believe that in the USA Toyota has identified and corrected the PP aux battery poor performance problem by installing a 470 CCA battery in place of the original 285 CCA battery in my PP.

    1) [​IMG]


    2) upload_2024-9-20_14-15-42.jpeg
     
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  2. GcinFl

    GcinFl New Member

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    RandyPete thank you for the update on your battery. Question: What were the circumstances that led to Toyota replacing your battery under warranty? Did your vehicle not start and you called them for a jump? My 12V drains from 12.4 after driving to 12.05 or so in 3 days. If I don't put it on a trickle charger it will drop below 12V. I had it checked out at the dealer and they said there was no problem, it was healthy. I feel it won't last the 3 year warranty period and would like to have it replaced sooner or later. Should I just let it go dead then call them for service? How did it work for you? Thanks.
     
  3. RandyPete

    RandyPete Member

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    Long story about how this happened for me. Short edition without the details and drama:

    The Vehicle Climate system failed. Lost its charge (A/C gas charge) because of a leak in the Traction Battery where the climate system can heat or cool the battery during charge or discharge.
    Vehicle sat in lot of local toyota dealer for 3 months while a replacement traction battery was shipped from Japan to US and on to the dealership. The dealership did nothing to the 12v aux battery system while it was left idle in their lot for the three months. When I went to the delalership after a two month wait to check on the vehicles condition, the 12v battery would not even provide enough power to unlock the front door of the vehicle (had to use mechanical key to get in the vehicle). The vehicle would not even enter the READY mode when trying to start the vehicle.

    After three months, dealership called me saying come pickup your Prius. I did and in a day or two the paperwork was complete for the traction Battery replacement under warranty. Upon returning to the dealership for the Traction Battery warranry replacement paperwork, I reminded the service writer of my request for them to test and replace the 12v battery under warranty. It took about three days or so, but they claimed to have replaced the 12v battery, its replacement under warranry was even itemized on the service order details I recieved. Battery cost and labor cost itemized, all under warranry.

    Unfortunately they did not install the replacement 12v battery, I checked and found the original 12v batttery still in place a few days later. One more trip to the local dealership, some discussion and lookie lew at the 12v battery and they agreed to replace the 12v battery. That's what happened.

    The dealership had a hard time testing the 12v battery for replacement under warranty. I do believe that when you take your Prius to the dealership and complain about poor battery performance they may agree to test it. But good luck getting them to replace it. Their test quite often denies failure of the battery. YMMV. Good Luck.
     
    #3 RandyPete, Sep 20, 2024
    Last edited: Sep 20, 2024
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  4. bisco

    bisco cookie crumbler

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    i think there is a tsb for connected services draining the 12 volt
     
  5. RandyPete

    RandyPete Member

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    I do not have any connected services in my Prius Prime.
     
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  6. Hammersmith

    Hammersmith Senior Member

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    No there isn't.
     
  7. Gokhan

    Gokhan Senior Member

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    The difference in the CCA is only because they are using different test standards—the EN test standard on the GS Yuasa (shown in parentheses next to CCA) vs. one of the many other standards on the Toyota TrueStart. They are both standard calcium flooded-cell batteries (neither is an enhanced flooded-cell battery (EFB)), and therefore, their specs and performance should be very similar, like those for any standard calcium flooded-cell battery.

    Here are the different CCA standards from the Ancel BT521 LCD-display battery charger/maintainer/tester user guide.

    [​IMG]

    It looks like you have a battery monitor connected. Keep monitoring it. You might want to get a Noco Genius 1 (or 2, or 5) and occasionally manually fully charge the battery.
     
    #7 Gokhan, Sep 20, 2024
    Last edited: Sep 20, 2024
  8. Gokhan

    Gokhan Senior Member

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    Definitely get a Noco Genius 1 (or a Noco Genius 5 if you don't mind spending more money) ASAP and manually fully charge your battery. You are right that your battery voltage is way too low and you could be left stranded at any time.
     
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  9. RandyPete

    RandyPete Member

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    I do have a BM2 battery monitor installed. It records the battery voltage intermittently (about every two minutes) and I can use bluetooth to monitor,display or record that data on my phone. It is a voltmeter, not a SOC meter. I can download view the Battery Monitor voltage data with the Battery Monitor app (V). I can view and/or download the Battery Monitor voltage data (csv files) to the phone using the JMP BatteryMon II bluetooth app.

    I have been using a CTEK Multi US 7200 Battery Charger for lead acid 14-150 AH batteries for years now. I have two of them. One keeps the Odyssey batteries in my Ford F250 Diesel pickup in good shape (It sits parked for sometimes a month at a time). The other is in my Jeep with an Odyssey red top AGM battery to keep that battery in good shape while parked waiting for the next adventure. They are Multi Stage fully automatic Chargers. Stages include desulfite, soft start, bulk, analysis, absorb, recondition, float and pulse. They have four different charging modes, normal, snow flake, supply and recond.

    I have used these chargers for years to keep my expensive lead acid batteries in good shape when they are parked (OOS) for days, weeks, months on end. I'll stick with the CTEK Multi US 7002 and use it on the Prius battery (Manual hookup) if the battery voltage ever drops to 12.3v at rest.

    (side note: Both the truck and jeep alternators hold the battery charging voltage 14.0-.1 v when the vehicle engine is running (one is an alternator used to charge the battery or when I want to weld with a Premier Power welder setup with an external regulator, the other is a High Power heavy duty aftermarket aternator with a good regulator.)
     
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  10. Gokhan

    Gokhan Senior Member

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    Yeah, I wouldn't trust the SOC levels in the BM2 app. The true SOC, SOH, and SOF can only be estimated if both the voltage and current are monitored.

    That's an expensive charger. The Ancel BT521 LCD-display battery charger/maintainer/tester I mentioned above also seems very nice, with an LCD display for the voltage and current as well as a lot of customization through the menus.
     
  11. Gokhan

    Gokhan Senior Member

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    You also seem to have connected the negative terminal of your battery monitor to the chassis (to the chassis terminal of the battery sensor to be exact). So, the battery-monitor voltage will be slightly off at high currents (slightly lower when discharging and slightly higher when charging) because of the voltage-drop across the shunt resistor of the battery sensor, but then, the 1.5-mA battery-monitor current goes through the battery sensor if that matters.
     
    #11 Gokhan, Sep 21, 2024
    Last edited: Sep 21, 2024
  12. RandyPete

    RandyPete Member

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    So are you suggesting that I connect the '-' terminal of the battery monitor lead under the nut that secures the '-' battery clamp to the battery post ? I think I tried that but was not successful in backing that nut off far enough to make room for the thickness of the connector on that BM '-' lead. Did you make that connection configuration work for you ?
     
  13. Gokhan

    Gokhan Senior Member

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    That would result in a higher voltage accuracy at higher currents because the Ohm's-law voltage drop across the shunt resistor is not included in the battery-monitor voltage.

    In my Gen 4, I had some trouble installing the U-shaped terminal on the negative side as well. What I did was to carefully bend it and then slide it under the washer instead of under the nut tightening the connector to the battery post because the nut was too small for the U-shaped terminal and it kept sliding out when I tightened it.

    From your pictures, I am not exactly sure what the problem in your Gen 5 is though, as the screw is very long. However, you don't seem to have a washer under the nut, and you could have the same sliding-out problem for the U-shaped terminal.

    Looking at the pictures of my car when it was new, the battery terminals were oil-free. Now, there is oil on them. Go figure how the oil got there. A dealer technician lubricated my battery terminals at service? The last three pictures are just before I replaced the OEM battery. I will post a picture of the Uplus AGM battery installed with the battery monitor at some point.

    [​IMG]
    [​IMG]
    [​IMG]
    [​IMG]
     
    #13 Gokhan, Sep 21, 2024
    Last edited: Sep 21, 2024
  14. Trollbait

    Trollbait It's a D&D thing

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  15. Mr.Vanvandenburg

    Mr.Vanvandenburg Senior Member

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    I installed a bm2 first on the battery and then to the neg on the washer bottle screw. That monitor went up to my daughters Camry hybrid. Now I have Ancel monitors on my two cars. I think there is no measurable difference in any of it but I want all loads through the sensor because that what it is supposed to read, and you don’t want a load separate across the battery no matter how small.
    A really good battery charger regimen was with the Clores.
    Something seems amiss when a battery ends up over 13 volts after charging, I have one small cheap charger that did that to my truck battery, it took weeks to get back down to the usual 12.7 or so value sitting unused. It sat in absorption mode for a day or two. Same cheap but UL listed charger brings my Prime battery in the 12.7’s. Daughter has the Noco 4 amp I bought her, will be going up there this weekend and see what monitor has been reading. She puts it in on every day as battery is in the trunk, no hood to be popping. Maybe she doesn’t need to do that every day. I told her it is good to keep a battery of this type fully charged.
     
  16. RandyPete

    RandyPete Member

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    I like the CTEK convesion Table CCA to EN. Thanks for posting the link.
    Is there a relationshop between Battery CCA and AH specs ?
    The True Start Battery does not have an AH number on the battery label.
    I cannot find a source for True Start battery AH specs.
    As I recall over my years of using automotive lead acid batteries, most of them did not have a published AH rating.
     
  17. Gokhan

    Gokhan Senior Member

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    Hmm, I wonder why the GS Yuasa CCA is that low then. Cheapo OEM battery?

    There is really no relationship between the CCA and reserve capacity (RC) or 20-hour Ah capacity.

    There are conversion tables from RC in minutes to 20-hour Ah capacity; however, it is not an exact conversion, as different batteries will map differently because the two tests are carried out with different current draws, the RC test typically using a current more than ten times higher as the much slower-drain 20-hour Ah test.

    That said, the 20-hour Ah capacity of the ToyotaStart H4 seems quite low, corresponding to about 40–44 Ah according to the 74-minute RC given on the label. So, its 20-hour Ah capacity is no higher than the GS Yuasa and possibly lower. But then, a cheapo OEM battery again. In comparison, most EN LN1 batteries, including the Uplus AGM I installed, have a standard 50-Ah 20-hour capacity and a standard 80-minute RC. Walmart EverStart Maxx 140R claims a 95-minute RC. AGM batteries will have a higher CCA than flooded- and enhanced flooded-cell batteries for a given battery group size.

    Here is the ACDelco battery-specification chart where you can look up the RC and 20-hour Ah values:

    https://www.dstgateway.com/ACDelcoDocuments/BatterySpecifications.pdf
     
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  18. Gokhan

    Gokhan Senior Member

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    I am still not convinced that the 295 and 285 CCA (EN) values on the OEM GS Yuasa Gen 4 and Gen 5 batteries, respectively, are correct. Even for a cheapo battery, they sound way too low.

    Perhaps they accidentally used the DIN CCA standard, which is less than 2/3 of the SAE CCA and ended up mislabeling it, and then it would make sense. In fact, according to the conversion formula given by GS Yuasa, 470 CCA (SAE) is equal to (470−40)×0.66 = 284 CCA (DIN), the latter of which is exactly what is on the GS Yuasa label.

    Here is the conversion information from GS Yuasa. There are actually two EN CCA standards as well—EN1 CCA and EN2 CCA.

    Guide to understanding battery specifications—GS Yuasa
     
    #18 Gokhan, Sep 21, 2024
    Last edited: Sep 21, 2024
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