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DIY 12V Battery Replacement Add'nl Info

Discussion in 'Gen 4 Prius Care, Maintenance and Troubleshooting' started by Elektroingenieur, Mar 17, 2018.

  1. Mendel Leisk

    Mendel Leisk Senior Member

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    Think I’ll add this to my sig: having battery tested with an electronic load tester is much more accurate than an internet opinion poll.
     
    Doug McC likes this.
  2. Elektroingenieur

    Elektroingenieur Senior Member

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    If the car had been unused or lightly used, the battery may have just needed recharging, and indeed, it might still not be fully charged. Whether or not you replace the battery, if you expect not to be driving much for a while, consider using an external battery charger.
    When using accessories while parked, it’s better to keep the car in READY, so the engine can run as needed to keep the batteries charged.
    That’s good advice for cars that are in regular use. In this situation, I’d suggest giving the battery a fair chance to recover, rather than just replacing it out of hand.
     
  3. Mendel Leisk

    Mendel Leisk Senior Member

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    Ours pretty much LIVES on a charger. Appreciate this is not practical for street or apartment parking lots, but just saying’.
     
  4. thomassster

    thomassster Member

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    There are so many variables when the time for a new battery. It’s basic general battery life questions like is it being exposed to hot environments constantly, have the battery let die multiple times, is it about 4-6 years old? Funny I was at advanced auto parts store and some women with a 2016 Prius came in and was needing a new battery.

    I would think a lot of people with 2016s would be checking out this thread soon if they haven’t before.
     
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  5. Prodigyplace

    Prodigyplace Senior Member

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    Why?? Like any other car if you drain it using the radio or other accessories the battery will fail. My 2017 is still going strong but I do not abuse it.

    I am looking at this thread mainly for future reference.
     
  6. Elt31987

    Elt31987 Active Member

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    I'm still on my original 12v from 2016. I test it once a month with a Topdon tester and it comes back with a state of health of 97%, internal resistance less than 10 ohms, and puts out around 320 CCA. Sure its just a matter of time, but i have a high quality lithium ion portable jumper, so if it dies, i jump it and go to one of the many auto parts stores around. Plus im curious as to how long its going to last.
     
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  7. UltraJetRefill

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    I'm getting ready to replace a 4 year old battery, and just wanted to get opinions on connecting another battery in parallel to maintain the car's settings while the new one is installed. I have a couple of 12 V batteries, and I'm wondering if the 7 Ah (left) would suffice. I have some 18 AWG test leads as well. I won't be starting the car with the battery attached, so I'm assuming that the 18 AWG wires should work without releasing all of the magic smoke.

    Does this sound OK? I really just don't want to have to go back to the dealer and get the constant backup beep turned off, as well as losing all of the fuel economy data, etc.
     

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  8. PiPLosAngeles

    PiPLosAngeles Senior Member

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    As long as you make sure not to short the wires I don't see why it would be a problem. Let us know how it goes.

    Some people like to use products that connect to the ODBII port.
     
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  9. Elt31987

    Elt31987 Active Member

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    I used an obd Ii adapter that plugged Into my portable jump starter
     
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  10. ChapmanF

    ChapmanF Senior Member

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    So far, I haven't needed to replace a Prius aux battery younger than ten years. But I've been driving the earlier generations, with the battery in a protected location in the cabin.

    With Gen 4 moving the battery out under the hood like conventional cars, it's possible the longevity will be more like what conventional cars see.
     
  11. PiPLosAngeles

    PiPLosAngeles Senior Member

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    FWIW that's been my experience as well. My 2012 PiP still has the original 12V battery.
     
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  12. UltraJetRefill

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    My wife's 2017 had its battery die after four years, and it was a nightmare finding the TruStart for it (supply chain issues). I decided to be proactive with mine (6 months younger), and just swap out the battery before the upcoming grueling Arizona summer.
     
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  13. jerrymildred

    jerrymildred Senior Member

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    As mentioned before, it's OK is you're careful with the positive cable.

    FWIW, though, when I replaced the battery in my wife's 2017 Prius, all I had to do was reset the date and time. Probably easier than getting another battery, connecting it, being extra careful with the red cable, and then putting it all away.
     
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  14. UltraJetRefill

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    Just a quick update: SUCCESS! I just used the smaller battery and everything was fine. Thanks again for double checking me. :)
     
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  15. Kenneth Owens

    Kenneth Owens New Member

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    I have a question regarding the Steering Sensor Zero Point Calibration. Can I replace the battery while it is in the garage then back it out and drive forward below 20mph until I get to the straight section of my street or do I need to park the car on the straight section before replacing the battery.
     
  16. jerrymildred

    jerrymildred Senior Member

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    All I did was put in the new battery, set the time and date, and drive it. There is no time or distance expiration.
     
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  17. Mendel Leisk

    Mendel Leisk Senior Member

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    I don't believe a battery disconnect will throw that calibration off??
     
  18. jerrymildred

    jerrymildred Senior Member

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    Actually, I had time this afternoon to look in the owners manual. I know. It's a crazy thing to do. But I didn't find anything about recalibrating steering. But it does mention the Intelligent Clearance Sonar.
    Screen Shot 2022-02-04 at 3.45.02 PM.png

    But, again, that was transparent and self calibrating when I replaced my wife's battery.

    Edit to add that I believe the steering centering is handled by the clockspring in the steering wheel as in other cars.
     
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  19. Mendel Leisk

    Mendel Leisk Senior Member

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    If you're getting pro's to change your 12 volt (and paying through the teeth), verfiy if they employ memory savers. It's trivial to hook up, saves some hassles.

    For DIY, I use a memory saver cable with my jump pack. The cable plugs into the obd port, but just has pins to supply 12 volt. The other end is cig lighter style plug. It also has indicator light, to confirm you've got connection.
     
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  20. Jburner

    Jburner Member

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    Have a 2016 with OEM Yuasa (Japanese) battery. It still reads 12.5-12.6 volts when sitting. What else do I need to do to check its health? Don't want to be stranded.