Winter is coming -- 12V question

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by cyberpriusII, Sep 19, 2020.

  1. cyberpriusII

    cyberpriusII Prodigyplace says I'm Super Kris

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    So, the wonderful and all-knowing National Weather Service is telling me that this winter in the Pacific Northwest will be colder with more snow than usual and all sorts of other bad things, such as dire wolves coming to feast on pets and so on.

    When I last checked my 12v, (May??), it read 12.1v. Yeah, a bit low. But no issues so far.

    So, a new batt is going to be $200, more or less. And, with my skills. 45 minutes of terror in replacing it....if I go that route.

    Any thoughts on what I might think about. In other words, if I check my 12v in the morning and it is still 12.1v, should I just go ahead and replace it....or live dangerously and take the chance of having to replace it in December. Wait, I think I am answering my own inquiry, which would be to replace now. Of course, it would be a bit of a financial hit to do it, but if it need be done....
     
  2. Mendel Leisk

    Mendel Leisk Senior Member

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    How old is it? Still, 12.1 is 12.1...
     
  3. cyberpriusII

    cyberpriusII Prodigyplace says I'm Super Kris

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    Six years old. Just a baby....
     
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  4. bisco

    bisco cookie crumbler

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    any place to have it load tested?
     
  5. frodoz737

    frodoz737 Top Wrench

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    6 years old...winter coming? Replace it and move on cyberpriusII.
     
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  6. edthefox5

    edthefox5 Senior Member

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    Hi Kris-
    Replace it asap. Just unclick the 2 power leads from the positive post assy and your good to go no sparks only hassle then is the weight of the battery putting it in the hole. That's why you have a husband. Unless you want to be proud and hurt yourself.

    Before installing the new battery take a close look at how the negative lead is bolted onto the negative post. Replicate my photo. Bolt that neg lead onto the battery before it goes in the hole. Sand down the connection area where the negative lead is bolted to the chassis and then lube it all up with synthetic grease.

    Owned my 07 13 years and on its 3rd battery never any 12 volt battery drama because I do not let it bite me.

    I have seen enough horrific 12 volt battery story's on here. Not me.

    Cold winter coming you have been warned.

    Giddy up and good luck and don't hurt yourself.
     

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    #6 edthefox5, Sep 19, 2020
    Last edited: Sep 19, 2020
  7. bat4255

    bat4255 2016 Prius v #2 and 2008 Gen II #2

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    My '08 12v was replaced 4 years ago. It is always garaged with winters going down to -20 (f), but it was a bit sketchy the last year it was in, so it was 8yrs old.

    If the car is not garaged and you have cold temps 0 (f) and 6yrs. old in a remote area, Replace it .
     
  8. jzchen

    jzchen Senior Member

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    Have a charger/maintainer? Charge it up or drive it. Turn off the car or disconnect charger. Run high beams 30 secs and then measure voltage at the terminals and report. I don't have the ranges in my mind offhand but I can look them up...

    moto g(7) power ?
     
  9. sam spade 2

    sam spade 2 Senior Member

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    Given where you live (not real HOT for long periods), it might be "just a baby".
    But for most people, it would be time for a change.

    The BIG question is:
    Since you probably can park it anywhere you want, in relation to the house or garage............
    Why have you NOT had it connected to a battery tender during it's down time ?
    If you would do that now, you might get a couple of more years out of it.
    For a cost of maybe $35 instead $200.

    What are you using to measure that 12.1 ??g

    Note: Cold is NOT hard on batteries, except that it causes a temporary loss of capacity.
    This is more significant when it must supply a lot of current for an actual starter motor (cold cranking amps).
    A fully charged battery stored in the cold ages MUCH less than if it was hot.
     
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  10. Salamander_King

    Salamander_King Senior Member

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    +1

    I don't know if 6years is automatic preemptive replacement time. I have had an original 12v battery in my car for 10+ years. However, I have not had to deal with a dead 12v battery issue with Prius yet, but all the other cars I had to deal with it, it was not bad at all, since it always happened only in the morning after a very cold night. Yeah, I had to jump-start the car, but after jumping and charging the battery for a while, I had enough time to look around and buy and replace the failing 12v battery in my leisure time later on.

    That being said, at current COVID-19 restriction and not driving my Prius Prime every day, I have installed a Bluetooth battery monitor and keep close eyes on the battery SoC. When it drops below 12.4v, I promptly plug the 12v battery to the external smart charger to replenish the SoC. I plan to keep doing this routine as long as I own the car, and hoping the 12v battery will go much longer than average in our region which is ~6 years.
     
  11. sam spade 2

    sam spade 2 Senior Member

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    MUCH more complicated than it needs to be.
    The "smart" charger is made to be left connected ALL the time.
    Doing that will actually give it a loner life than what you are doing.
     
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  12. Salamander_King

    Salamander_King Senior Member

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    If the car is stored in a garage and not driven for a long time, then yeah, I will keep the smart charger connected all the time. But, my car is parked outside, and even though it is now much less frequent than usual, the car is being driven whenever I need to go somewhere. I don't want a long extension cord attached to my car and the hood kept open all the time. The system is not complicated at all. It makes monitoring the 12v battery SoC very easy and makes knowing when to charge a simple routine.
     
    #12 Salamander_King, Sep 20, 2020
    Last edited: Sep 20, 2020
  13. sam spade 2

    sam spade 2 Senior Member

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    Even for your periodic re-charges, it would be MUCH better to permanently attach an SAE battery connector to the "jump points"
    and run it out the front through the grill for a quick attachment without opening the hood.
     
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  14. Salamander_King

    Salamander_King Senior Member

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    I actually have an even better plan than that. I thought about attaching 12v ring terminal SAE to O ring connectors extension cord cable like pictured below to the 12v battery post (remember on Prime and Gen4 there are no jump posts under the hood) and routing the SAE connector end through the grille as you suggested, but then I had some what-if questions. How waterproof is the SAE connector end? What happens if for some reason the end of the SAE connector which is dangling out from the front grille opening gets wet? Even if the connector is watertight and protected, what happens if the cord running from the 12v battery gets somehow damaged and shorted? Also if I did this, I have to have the battery charger out of the car in sometimes wet conditions such as rain and snow and exposed to anyone to unplug and take it.

    upload_2020-9-21_18-35-49.png

    For that fear, I decided to install an onboard 12v battery charger/maintainer under the hood. I just have to modify the front grille a bit to install ac port plug-in adapter that accepts the extension cord from the power source directly like the one shown below. I have all the parts and the on-board charger, but I have not finished the mod yet, until then, I will continue to use the extension cord through the open hood. I will be glad to share the final finished mod with everyone when it's done.
    upload_2020-9-21_18-54-30.png

    upload_2020-9-21_18-49-58.png
     
    #14 Salamander_King, Sep 21, 2020
    Last edited: Sep 21, 2020
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  15. Mendel Leisk

    Mendel Leisk Senior Member

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    I had similar concerns, running a 12 volt extension out to an outside charger. An under-the-hood charger and AC connection in the grill is better.
     
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  16. cyberpriusII

    cyberpriusII Prodigyplace says I'm Super Kris

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    OP again.

    O.K. I guess I will confess. I am just too lazy to deal with hooking up a "tender/charger" every day. First, I have lots of room to park, but none of it under cover. So, it is exposed not only to the elements, which can be overcome, but to the critters, which includes domestic pets and I cannot preclude my mutts deciding to "take a bite of cable" just for the heck of it all.

    I tested the volts with my $50 Klein multi-tester/voltmeter that I bought the last time my 12v died. "Uart," an Aussie whom used to post here -- maybe still does -- instructed me on use of said meter.

    I suppose I will lean toward replacement of the 12v. Last time I did it, it took me two hours, but this time, maybe 40 minutes. I will only use the Yusa from Toyota and I know the local place charges around $230, but I am usually able to talk them down a few cents -- of course, I am not 25 years old anymore....

    Only concern is that my right arm is still having issues since I injured it a bit ago. It tends to want to drop things sometimes -- a bit scary when it is a toddler or a glass....well life is all about risks, eh, Bisco?
    kris
    (I really ought to update my photo, but I do not find my recent scars too flattering).
     
  17. jzchen

    jzchen Senior Member

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    There are chargers with IP65 ratings for water resistance. Connect underhood as necessary, run the cord out the hood then drop the hood but do not completely close. If the engine is hot leave the charger on a block underneath the car.

    Still happy with my roughly 9.8/9.9 lb Chinese LiFePO4 battery. It's a little more now and this is from a different seller, but I confirmed with seller this has backup cell if main is drained dead. Just be sure you request 46B24R if you change your mind about Yuasa.

    DOHON 12 Volt 46B24L 850CCA Lithium Phosphate Battery LiFePO4 For Auto Boat | eBay

    moto g(7) power ?
     
  18. sam spade 2

    sam spade 2 Senior Member

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    In some cases. Not if you want to use the charger on other vehicles too.
     
  19. Kenny94945

    Kenny94945 Active Member

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    FWIW.
    Six year old battery?
    Some could say you are living on borrowed time.
    I'd replace now to ease your wet winter and possible no-start worries.
    Noting: a no start may ruin your day, so is that worth having the expense now?

    IMO
    I would think, as you are a long time forum co-member, that the 12v battery replacement will be easy for you to DIY replace.
    What's the worst case? Towing fee, 1/2 hour of shop time expense plus battery cost?
    Maybe even negotiate a deal now; buy a battery from a dealer with free install?

    Good luck with your decision.
     
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  20. Synthetic

    Synthetic Junior Member

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    You could "meet in the middle" so to speak and leave the old battery installed, keep that $200 in your Levis, and instead spend $50 of that and buy a Li-ion battery jumper for when that old 12V gives up on your wild ways. Of course, the 12V will fail at that exact moment when you are on the way to deliver a baby (yours or someone else's), it is snowing like mad, it is also midnight, you are far into the boondocks, out of cel range, and nearly out of gas.

    Or, buy a new 12V at Pep Boys or Auto Zone and they'll install it for you for nothing.
     
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