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12v battery died for no reason

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by rogerchin, Sep 11, 2024 at 3:19 AM.

  1. rogerchin

    rogerchin New Member

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    2008 Prius
    Model:
    Base
    So I had an appointmen to bring my car to a shop to repair a damage from an accident. Long story short, the car had no battery problems prior, drove to the shop 22km away, shut it off, went inside to hand over the keys, forgot something in the car, went back to get the keys not even 5 minutes after shutting the car off, and the car won't respond to the unlock/unarming. Luckily I didn't lock/arm the car, so I was able to get inside. Car wouldn't start.

    Fast forward about a week, the car is fixed. The tech at the shop had to keep jump starting the car to move it. But when I went to pick it up, they couldn't jump it to move it anymore. Red triangle came on, "problem" message came up, etc. etc.I can get the car into ready, but whenever I shift to R or D, it dies. They kept the booster/generator thing on the car for about 15 min. and they gave up because they had to close the shop and go home and said I can stay there and wait for a tow truck.

    Anyways, BCAA (a roadside assistance service) sent a service guy over around 2 hours after the shop closed and was able to jump/boost the car. Car started, no triangle, and it was ready to go. While I was waiting for BCAA, I bought a new battery from a shop nearby.

    Drove the car home, parked, shut it off and bam, dead again. Too tired to worry about it and went to bed. Next day, woke up, changed the old battery to the new battery. Took the battery to an outlet and had a charger pack charged it for about 8 hours, got it to full according to the charger pack.

    So my question is, how can a battery just suddenly die like that without any warning? It's the original battery. Is it a bad now? I'm really hoping to god it's not anything to do with my car, like a parasitic drain or something and that the battery is in fact bad. How can I test it? It's sitting outside my door right now, fully charged.
     
    #1 rogerchin, Sep 11, 2024 at 3:19 AM
  2. Tombukt2

    Tombukt2 Senior Member

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    You have to look online or if you're an electrical engineer you know how to set up your test meter between the battery and the positive terminal or whatever it is or the battery and the negative terminal rather and just let it sit there and look at the milliamps that the battery's pulling with everything sitting there off The hatch closed and you can either have the meter running through the hatch the hatch won't kill the wires the gasket just closes around them and you can watch the display I can't remember the numbers but anything over like 50 milliamps or something like that is not good and then you can unplug fuses and see when that drops substantially and what is on that circuit that sort of thing.
     
    #2 Tombukt2, Sep 11, 2024 at 8:04 AM
  3. TMR-JWAP

    TMR-JWAP Senior Member

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    how can a battery just suddenly die like that without any warning? It's the original battery.

    You just answered your own question. An original 12vbattery in a 2008? 16 years is a pretty impressive run, you more than got your moneys' worth. Most 12v batteries are on borrowed time at the 5 year point.
     
    #3 TMR-JWAP, Sep 11, 2024 at 10:09 AM
    BiomedO1 likes this.
  4. BiomedO1

    BiomedO1 Senior Member

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    LE
    Plus the fact that you got into an accident. The way batteries are built, any sudden jolts can short the positive and negative plates together. That's why off-road rigs tend to use the expensive spiral plated batteries.

    Hope this helps......

    I lost my 13 year old battery when a grandma back into my car in a parking lot. No damage to the car, except a scratch on the bumper - but a few days later, the battery was below 11VDC and wouldn't start the car.:(
     
    #4 BiomedO1, Sep 11, 2024 at 10:20 AM
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