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Prius Not Driven for over 12 months - is 12V battery salvagable?

Discussion in 'Generation 1 Prius Discussion' started by Alexwasalreadytaken, Jan 25, 2024.

  1. Alexwasalreadytaken

    Alexwasalreadytaken Junior Member

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    My Gen 1 Prius started experiencing issues last January. I have been meaning to sell it, but other things got in the way, and it has been sitting in my driveway unused for the last 12 months. Unsurprisingly, the 12V battery died during that time. I tried jumping it, but the car is still not starting, though the electronics power on when hooked up to my other car's battery.

    I know these 12V's are pricey for some reason after replacing it about 6 years ago, so I bought a trickle charger with a repair mode off of Amazon to try to save the battery, but I've never used one before, and I'm nervous about the possibility of starting a fire by trying to charge a battery which has dried out (I don't know if that could happen, I have never done this before).

    Is it worth trying to save the battery? Or will attempting to recharge it be dangerous? Also, if recharging it, is it necessary to remove the battery from the car?

    Thanks for your help.
     
  2. bisco

    bisco cookie crumbler

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  3. Josey

    Josey Active Member

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    I don't know what you bought as a trickle charger, but you probably don't need to be nervous about it. You won't start a fire with one (unless maybe you have an open can of gasoline around and make a spark while hooking it up).

    But right now a trickle charger isn't really what you want for best results. A decent quality "smart" charger that works with AGM batteries would be best. Either way, charge the thing up and see what happens. But a trickle charger won't set anything on fire.

    You don't need to remove it from the car, although I always do - it's just a preference. I don't want my trunk open or my charger cables closed up in the trunk lid. But I also don't use a trickle charger.

    Do you have a voltmeter? Get the thing up to full charge. Drive the car around for a week or so, and monitor the 12V battery voltage each time you let it sit over night or so. A healthy, original AGM battery should have a "resting charge" (after sitting) very near 13V (figure 12.7-13V). If you consistently find it sitting below...[very fuzzy number]...12.5 or so, then suspect that the battery is nearing its end. If you find it sitting nearer to 12.0V - first worry about a parasitic current draw. And then worry about the battery.
     
  4. ammdb

    ammdb Active Member

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    Charging with a trickle charger and the battery in the car for 12 to 24 hours won't hurt anything and isn't dangerous. If this brings the charge back up over 12V the battery might work for a while longer. Being six years old it's probably time to change anyway.
     
  5. Tombukt2

    Tombukt2 Senior Member

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    Just hook it up see what happens probably nothing it'll sit there in the yellow mode and do nothing eventually flashing yellow and red or something and telling you the battery is bad no matter If you don't want to replace it you don't want to replace it well that's a personal issue to sell it you'll probably need a battery in it so that people can see that it runs and starts and can drive then I guess you can tell them well not battery doesn't come with the car other than thinking you're quite the weirdo I guess that might could work out personally I don't see it. Usually if I go look at a car and I walk up to it and it's not capable of running starting driving or any of that then all of a sudden we've gone from $3,000 to 500 like instantaneously. At least in my world a non-runner non-starter people talking funny and all that that's instantaneous parts car tow lot car might not have any paperwork whatever.
     
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  6. Trombone

    Trombone Member

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    This is somewhat off-topic, but related FYI in re: the 12V battery. I'm currently (pun intended!) using a lawn/garden tractor battery in my '02 (Duracell Ultra Heavy Duty BCI Group U1R 12V 350CCA Lawn & Garden Battery - SLIU1RXHD at Batteries Plus). I went to the bother of converting the car's OE battery clamps to SAE, and then bolting on flag-to-post terminals to the battery (Deka #02033, these Flag to Post Battery Terminal Adapters | L to Round Terminal), but another member here, I think it was ronlewis, said that he bolted the OE clamps directly to the flag terminals with success. So far this winter the battery has performed just fine, even on single-digit temperature days (of which we don't get many in e. PA). I'll be interested to learn the life expectancy of the Duracell in this application.

    BTW, there is (or was--seems to be out of stock in my area) a less-expensive lawn/garden battery available from WallyWorld (EverStart Lead Acid Lawn and Garden Battery, Group Size U1R 12 Volt, 230 CCA - Walmart.com).
     
    #6 Trombone, Jan 26, 2024
    Last edited: Jan 26, 2024
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  7. ronlewis

    ronlewis Active Member

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    I bought that Walmart battery just last week. In stock in Houston. $47.33 after $13 core charge I'll get back. Sounds like the OP has time for them to ship it in. Since you have the trickle charge, grab a couple and keep one on the charger. They have a 6-month warranty, and you know how good Walmart is about returns (not that I'm suggesting you return it discharged in 5 months), but I've been getting more than that when driven regularly. They don't do well with sitting unused for long (only 230 cranking amps compared to Toyotas which, IIRC, are 280 or more).

    But, at that price, you can buy 10 before you can buy a Toyota battery. There are other similar solutions. You just have to make sure the terminals line up correctly (that's the R in U1R) and that they can be adapted for the cars terminal cables. The Toyota batteries have non-standard, small diameter terminals that most batteries don't have. Toyota does offer an adapter kit to use standard-sized battery terminals.

    However, the Walmart batteries have the flat terminals, not poles, which happen to work with our car's smaller cables. You simply have to spread the cable end slightly (inserting a flat screwdriver in between and twisting is sufficient) to fit over the thickness of the battery terminal and iine the same screw holes over the hole in the battery terminal. Use the same screw to tighter both down. Only thing - you probably have to pop some small green plastic inserts out of the cable terminals. No biggie.
     
  8. ronlewis

    ronlewis Active Member

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    Another choice is to just put any large 12v in your trunk and jumper cable the positive posts and ground your big battery to the car (the metal above the HV battery around the hinge/blower motor works). Takes up space but works the same. Great program at LKQ Pick-u-Parts yard if you have one nearby - I think it's $50 for a lifetime battery. Just bring yours back when it goes bad and they give you another one. They're already removed from the junk car, so no extra work. I don't know what they sell them for without the lifetime warranty, but each location posts a price list online.

    Disclaimer: I've only noticed that promo sign at their yards, IDK any details, as in, whether it's tied to the life of a vehicle (I don't think so). I think it's just the battery's lifetime. Legally, it's sure to have some time limit - neverending contracts aren't enforceable.
     
  9. Trombone

    Trombone Member

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    Yeah, really strange that this battery should be OS in my location, since the Wally battery is made right up the road here at Deka in Berks County (or "kaundy," as the PA Dutch spell it). Deka has an outlet store at the factory, so I have that option if needed---which it isn't, at the moment.
     
  10. ptero

    ptero New Member

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    And, have you made any progress, Alex?
    Btw., the motor is not started by the 12V-battery, it is started by the high-voltage-hybrid-battery. The 12V-battery just energizes the electronics, inverter so that the hybrid system can boot, so to speak.. With a working 12V-battery and a dead HV-hybrid-battery your car won't start.
    Maybe you know all that already and my answer was for nothing, so sorry if that's the case.


    Source: German Prius Wiki
    12V-Batterie – Prius Wiki
    "Für den Verbrennerstart ist die Hybrid-Batterie in Zusammenarbeit mit MG1 als Starter zuständig."
    DeepL translation:
    The hybrid battery is responsible for starting the combustion engine in conjunction with MG1 as the starter.
     
    #10 ptero, Mar 6, 2024
    Last edited: Mar 6, 2024
  11. Tombukt2

    Tombukt2 Senior Member

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    If you're willing to make up the proper terminal ends to match the battery you want to stick in the back of your car the choices get very wide very quickly We have people running alarm batteries elevator batteries all kinds of nonsense back there Cold cranking amps is not really a good measure for this particular battery and this installation but it's a guide I guess we're not going to be cranking anything cold or hot there's nothing to crank No motors to turn except for the windshield wipers and the door and trunk locks although not near anything near a starter motor that cranks an engine and a lot of computers to be held open and awake when needed but when that's going on the HV battery is sending 13 to 14 volts to the low voltage circuit to keep that maintained so it seems the 12 volt rarely gets very exercised like in a regular car cranks a starter so on and so forth here our battery just sits and wakes up a bunch of electronics and every so often might have to put on windshield wipers and I don't think the lights are really a big discussion unless you're running halogens and incandescent bulbs in every socket.
     
  12. ronlewis

    ronlewis Active Member

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    I just bought a different battery at Walmart. They were out of U1Rs but I saw a U1P I'd never seen before and they come with terminals on either side - just make sure you get the right one. They're 275 cranking amps instead of 230 like the U1Rs. Cost $35 instead of $30. They don't seem to be giving 6mo warranties anymore. The lady said 30 days, but not sure she knows.
     
  13. Tombukt2

    Tombukt2 Senior Member

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    Yeah Walmart changed up on the lawn mower batteries now it's only 30 days That's what I was told here in North Carolina just a few weeks ago.
     
  14. ronlewis

    ronlewis Active Member

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    Yeah, someone could raise a stink. It doesn't say on the EverStart battery or the receipt, and I bought it in the Auto department, where there are promos posted that all EverStart batteries have a 2-year warranty.
     
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  15. Mendel Leisk

    Mendel Leisk Luddite

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    Just for giggles I window-shopped for our 2010:

    SaskBattery, I believe this one is compatible:

    S46B24R (FP-AGM51JIS) - SaskBattery

    for $229.50 CDN, plus ~6% GST, no provincial sales tax (again about ~6%), and free shipping to from Saskatchewan to me on the west coast. And no core deposit

    Then I phoned our local dealership, enquired about the Toyota battery: $404.49 CDN, plus GST/PST (12%), cash-and-carry, plus $20 core deposit I'd assume.
     
  16. Victor Siles

    Victor Siles Junior Member

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    Well from my previous experience. My 1st Gen needed the Hybrid battery replaced. So the previous owner found one at his junk yard. But it came off a car with low miles that sat in the Junkyard over a year so it lost its charge. We replaced the battery in the trunk and still didn't kick over. We found out the Hybrid battery needs charging by having the front wheels spin. The way we got it started was by pulling it with his vehicle. The front wheels need to spin in order for the Hybrid battery to charge. The charging power seems to be connected with the transmission. Its like a motorcycle both do not have an alternator like your regular non electrical vehicles. So you need the front tires to spin in order for the Hybrid battery to start receiving charge. We pulled it for about 15-20 mins at 20 miles speed. And it worked. If you're thinking about doing something like this make sure you use a road where there's hardly any other vehicles around you and have the Prius in neutral when being pulled. When it reaches about 20 mins turn the ignition on it should kick over.
     
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  17. Tombukt2

    Tombukt2 Senior Member

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    Or in the south somebody somebody would take a big belt off the rig that they have for the sawmill Hook it up to the PTO of the tractor Jack the front of the car up and just turn the wheel with the tractors PTO with the vehicle not going anywhere you'd be able to get it up to about easily 1800 to 2,500 RPMs and boom a charging you are. More more city-fied folks would buy a 300 volt output DC charger and just run it for about an hour should get you real close to where you need to be from an outlet but that's pretty cool dragging the car down the road.
     
  18. Victor Siles

    Victor Siles Junior Member

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    Yeah for 2 guys who never removed and installed a Hybrid battery. We used up most of the afternoon. I wasn't going to jack up the car and spin the tires by hand.
     
  19. Trombone

    Trombone Member

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    You got lucky, flat towing the car. Streng verboten, as per owner's manual.
     
  20. Mendel Leisk

    Mendel Leisk Luddite

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    That’ll work with Gen 1? With later gens there’s no charging in neutral, believe it’s mentioned in owners manual.
     
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