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Weird startup issue - 2011 Prius

Discussion in 'Gen 3 Prius Main Forum' started by pandeyrajiv, Sep 21, 2016.

  1. pandeyrajiv

    pandeyrajiv Junior Member

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    Facing a weird issue -

    Day before yesterday my car refused to start in a parking lot at work and I got a chemical smell (sulpher type, kinda like battery acid). Anyhow, called AAA, got it jump started (which it did) and drove home thinking it *had* to be a 12V battery, which I have not changed since I bought it in Oct 2011 (since I have faced this startup problem in my earlier Prius years back and it turned out to be a dead battery).

    BTW, No special alert icons show up on my dashboard once the car has started...Nothing seems out of the ordinary.

    Anyhow, next morning, I got the same symptom in my garage...very weak start...you know the kind where you it looks like it is getting the last dying charge from the 12V battery and it made this weak beeping noise...anyhow, after 30 seconds of trying it came on and as expected, once the car started, the hybrid battery took over and everything ran perfectly.

    I drive up to my local Batteries Plus and tell the guy I need to replace my battery. He says he will check my physical battery as a first step and we go to the back of the car and when we actually get to the battery, everything looks pristine - not a piece of dirt anywhere (looks like it just rolled off the factory floor) and no signs of any acid leakage (which i was fully expecting given that sulpher/acid smell the other day). He tests the battery and strangely he says the battery is working perfectly and has the perfect charge so there has to be some other issue somewhere...Now I am confused, so leave and drive to my local Autozone thinking they can do a scan of the computer system...I got there, they say they cannot do that unless I have a indicator light of some issue that shows up...They did test the battery and they confirmed as well it was good.

    Now I am *really* puzzled. What on earth is going on. Every symptom is related to the startup but the battery is fine. Once the car starts up, I get no problem indicators on my dashboard...

    Does anyone have any idea what could be wrong?

    Thanks in advance

    Rajiv
     
  2. IMkenNY

    IMkenNY Im just being nosy

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    Unless you find something is draining the battery (dome, map, door, stuck brake light), I would lean towards the 12V battery being the culprit.
    If you measure the 12v ($5 harbor freight meter) an hour or so after you turn off the car with a load (head lights) I suspect you will see that the 12v is weak.
     
  3. BZzap!

    BZzap! Senior Member

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    If you are getting a sulfur smell I would suspect a shorted cell in the battery. The alternator is probably working overtime against the battery. If you can start the car, check the charge rate across the battery while the car is running. An unusually high rate of charge (above 14.2v) is a good indicator that the battery is defective. Also you can listen to the battery for a gurgling sound. This would be the short manifesting itself.
     
  4. pandeyrajiv

    pandeyrajiv Junior Member

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    Apologies if my questions are a bit naive but I am not an expert like many of you here...So if I understand you, I should get a Digital multimeter and measure the charge after an hour or so right? If so what should I be looking for - the reading should be lower than 12V (have no idea how to interpret what a multimeter shows)...
     
  5. pandeyrajiv

    pandeyrajiv Junior Member

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    So the strange thing is that the sulpher smell was ONLY there the first time, after that I have not got it...Now the difference is that when it happened the first time, it was parked all day in an open parking lot exposed to the sun with a 100+ degree F day...In my garage, it is parked inside a garage...

    Few other questions -
    1 - Does the Prius actually have an alternator like a regular car and does it actually charge the 12V battery?
    2- So if I measure (as per IMKenNY's suggestion above) using a digital multimeter, while the car is running (which I assume you mean, just turned on in my garage right?)
    3- And (if you agree with what I said above), if I see a high rate of charge then it is an indicator that the battery is defective. So my next question is - What *should* it be showing to show that all is good? I mean should it show a lower number?
    4- And I will be sure to listen closely for the gurgling sound. What is odd is that the battery looks pristine from the outside...Can it have a short and yet look good on the outside?

    Thanks for your patience, i am not a car savvy person so my questions may seem simple and stupid but I do want to learn.

    Thanks
    Rajiv
     
  6. JC91006

    JC91006 Senior Member

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    Make sure all the connections to your 12v is tight. Including the ground cable to the body of the car
     
  7. IMkenNY

    IMkenNY Im just being nosy

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    A good 12v battery should read 12v or higher an hour later with the head lights just turned on (you want to measure the battey with the car turned off and NOT in ready mode)
    Practice using the meter on a aa, aaa, c,d battery before heading out to the car, they should read 1.5 volt DC

    There is no alternator in the prius and since you are just experiencing a starting problem it is highly unlikely there is any problem with the 12v battery charging circuitry.

    If you want to validate the battery is being charged , measure the battery voltage with the car in ready mode and you can expect it to be above 13 volts
     
    #7 IMkenNY, Sep 21, 2016
    Last edited: Sep 21, 2016
  8. pandeyrajiv

    pandeyrajiv Junior Member

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    Thanks for the pointers (I am already getting smart :))...I watched a "How to" video to measure a car battery using a multimeter and I also saw some other intro videos so now I think I am ready...Will report back (as my neighbor has one handy).

    So if I read it right - I should go out, turn on the lights and then measure the charge with the lights turned on and it should not be weaker than 12.5 (or around) right?

    I am now wondering, can I measure even before I turn on the lights? The battery should measure around 12.5-12.7ish right?
     
  9. IMkenNY

    IMkenNY Im just being nosy

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    For grins I just measured mine with the car off and headlights just turned on and it came in at 12.29 volts on a one year old battery.
    The headlight load is more likely to point out a weak battery when measuring the voltage.
    In theory the two shops that you had checked the battery measured the battery voltage under the load of the tester they used but I have seen these pieces of test equipment get it wrong in the past.
     
    #9 IMkenNY, Sep 21, 2016
    Last edited: Sep 21, 2016
  10. Mendel Leisk

    Mendel Leisk Senior Member

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    You're misunderstanding: a reading lower that 12 volt would indicate a badly discharged battery. 12.6 or higher is good. below 12.5 is ailing, below 12.4 is getting seriously discharged, near due for replacement.

    I wonder how the test is using, with what instrument? There are electronic load testers that will check voltage and Cranking Amps, with a more in-depth "health check". Don't know if you want to splash out, but for around $60~70 there is consumer level Solar BA5. A competent battery retailer should have something but better, shop quality.
     
  11. pandeyrajiv

    pandeyrajiv Junior Member

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    Ok, so here is the update from the trenches...
    1 - Car off, nothing turned on, Reading: 12.8

    2 - Car off, headlights turned on for about a minute, Reading: 12.33

    3 - Car turned on ( I mean immediately, like nothing was wrong and the car has not been turned on since 5 PM yesterday), headlights turned on, stepped on the accelerator to cause the engine to kick in, Reading: 14.05

    4 - Car turned off, numbers slowly going down, after a minute, the reading was around 12.98

    Does this provide any clues?
     
  12. IMkenNY

    IMkenNY Im just being nosy

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    Those battery voltages sure look good, starting to look like something was / is draining the battery when the car is off.
    If it happens again check the battery voltage before the jump.
    I'm a big fan (I carry one in my Prius) of these new li ion jump battery packs. They are just a little bit larger than a deck of cards and hold their charge for 6 months.
    Very convenient for accidental battery discharge from leaving a light on.
    see sample link below from amazon (I don't own this unit below, shop around for best product/ price)

     
  13. pandeyrajiv

    pandeyrajiv Junior Member

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    Thanks for the feedback. The numbers did look good to me as well...I am still unable to figure out what could have possibly drained the battery...but the numbers do look good now and its been a few days with no real incidents. That is off course because we don't drive it thinking it might die...aside from driving to drop kids off where you dont turn off the car...I do keep the multimeter in the car so I can measure the numbers if it ever fails again but I don't feel secure driving around until I get that Li-ion jump starters you pointed me to (kinda expensive - 60+ bucks but may be worth it).

    Logic dictates that since the 12V battery essentially "boots" the system on the Prius and not really cause cranking of anything I am assuming you don't need that much juice to boost the Prius...Wondering if there is a cheap DIY way to make one with a few 9V batteries
     
  14. BZzap!

    BZzap! Senior Member

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    One of best thing I've ever purchased has been my PowerAll lithium ion battery bank.
    My Son and his wife are on vacation in France right now and the job of shifting cars around (City Sweeper schedule) on their street has befallen to me. Yesterday when I went to move their car (BMW...POS)it was dead as a door nail. Luckily I had my portable jump start kit with me. It's amazing, how such a small device can effortlessly , start a totally dead car. Money well spent.