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12v Battery Keeps Dying

Discussion in 'Generation 1 Prius Discussion' started by maverick4u, Dec 14, 2017.

  1. dolj

    dolj Senior Member

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    Thank you for clarifying. This was on your Gen 3?
     
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  2. Mendel Leisk

    Mendel Leisk Book Cover Judge

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  3. dolj

    dolj Senior Member

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    Thanks again. Interesting datapoint. It will be interesting to see if the Gen 1 is the same or similar.
     
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  4. maverick4u

    maverick4u Junior Member

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    The doors are closed and the car has been sitting overnight. What's interesting is when I pull the fuse that controls the dome light, radio and instrument display the load drops to like 5 milliamps. So I have a short in the dome light or radio most likely right? With that 15 amp fuse removed the battery stays fresh and the car starts every day.
     
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  5. Mendel Leisk

    Mendel Leisk Book Cover Judge

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    Did you measure milliamps with everything closed/idle? What did you get?
     
  6. LEVE

    LEVE Member

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    You're most likely seeing a draw that is the "keep alive" current to the radio. This keeps radio presets alive when the engine is off.

    As a matter of terminology, a "short" refers to a "dead short." That would result in a blown fuse. There is no such thing as a short that does not blow a fuse. A circuit can only exhibit three states:
    • a short, no current flow if the circuit fuse has blown.
    • an open, no current flow
    • a "draw", or flow of current.
    The last state, drawing current, of course, does not mean the circuit is working, nor does it mean it's bad.

    Unless you know what the circuit is supposed to draw when the vehicle is turned off, there is no real reference to define if the circuit is working, or not.

    To further isolate the problem charge the aux battery and simply unplug the radio and leave it overnight.

    Did the car start? If it does, the problem is in the radio.

    If the car does not start then the problem is in the dome lamp circuit. Did you pull the trunk light? Do you know for sure that it's turning off when you close the trunk?
     
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  7. maverick4u

    maverick4u Junior Member

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    I am positive the trunk light is turning off...I put my phone in the trunk and took a video of the event. I bought a radio off of eBay and am putting it in now. (Why didn't anyone tell me about the adventure that is? Had to super glue the center console plastic piece back together after it cracked on removal)

    After I get everything back together I will see if there's still a parasitic draw
     
    #27 maverick4u, Feb 6, 2018
    Last edited: Feb 6, 2018
  8. I'mJp

    I'mJp Senior Member

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    You can use the fuze box to trouble shoot.

    First you have to meter the current. Because of the battery placement, you will probably need someone to help you, they could sound out what the current is.

    With car car off, doors shut, hood open
    Find the aux fuze, measure before unplugging it, ask for a reading, put the fuze back.
    You want to put them back so that you don't mix them up.
    Go thru fuzes until you find the circuit that's doing the drain.
     
  9. maverick4u

    maverick4u Junior Member

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    I did that. It's the 15a fuse that controls the radio, dome light, and the energy monitor display. The radio kept going out on me so maybe the radio circuit was causing the draw? As soon as I clear the 6" of snow in my driveway I'm going to retest it. The new (used) radio I bought off of eBay is working just fine tho so maybe I did something right.
     
  10. maverick4u

    maverick4u Junior Member

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    Ok...the radio works fine now. It doesn't randomly go out and stop working. My super glued center console is holding up and the draw on the battery is down to like 6 ma. Seems to be working fine now.
    Now I just need to fix/replace the hybrid battery. I found a place that will put in a replacement gen2 battery for my gen1 battery for about $1400. Is that a decent price?

    Thanks for all the help guys!!
     
  11. Prodigyplace

    Prodigyplace 2025 Camry XLE FWD

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    You mean they will rebuild your Gen 1 pack with Gen 2 modules? The Gen 1 pack has more modules than a Gen 2 so they would need parts from at least two packs to rebuild yours. I believe new Toyota Gen 1 packs are less than the price you were quoted.

    The Gen 2 pack will not work in a Gen 1 Prius. Each generation pack is different. If they do not know that I would look elsewhere.
     
  12. maverick4u

    maverick4u Junior Member

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    Yes I believe the gen1 has 28 modules...they take a gen1 case and rebuild it with gen2 modules which apparently are more reliable than the gen1 modules.
    It's a company near Chicago....besthybridbatteries(dot)com. Anyone ever used them?
     
  13. dolj

    dolj Senior Member

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    In my opinion, no. Ask yourself this, in 6 months (or may be a year's time) will you think it is money well spent when this replacement tired and worn out pack (albeit a slightly less tired and worn out pack than your current one) starts giving you a P0A80 again?
    The Gen 1 has 38 modules, the Gen 2 has 28.

    However you slice it, you are replacing a tired and worn out pack with a slightly less tired and worn out pack, which is what a rebuilt is.

    You owe it to yourself to at least ask 2 or 3 dealers to quote you on how much a NEW pack is. You cannot compare a pack with NEW modules to a pack with OLD worn out modules.
     
    #33 dolj, Feb 21, 2018
    Last edited: Feb 21, 2018
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  14. maverick4u

    maverick4u Junior Member

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    I see...I had them mixed up. Buying a brand new hybrid battery will set you back about $3600...plus labor...that's more than the car is worth. Is it possible to just buy 38 new gen 2 modules and rebuild the battery yourself? That would cost about $1600 I believe.
     
  15. Prodigyplace

    Prodigyplace 2025 Camry XLE FWD

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  16. dolj

    dolj Senior Member

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    Have you actually priced it up recently? Toyota dropped their battery prices at the start of this year.
    Where will you buy new modules? You cannot buy (new) OEM modules from Toyota. 2k1toaster sells the only alternative new modules and his opinion is that he cannot sell a Gen 1 pack that is competitive with a new OEM pack. His modules are $1,600 for 14 modules, not the 19 you will need to replace the old Gen 1 modules. Note, 2k1toasters modules are equivalent to an OEM block which consists of 2 OEM modules, hence 14 and 19 vs 28 and 38.
    Where will you get 38 new modules for $1,600?
     
  17. Prodigyplace

    Prodigyplace 2025 Camry XLE FWD

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    You cannot buy new modules except as a battery pack from a dealer. It is rumored the newer Gen 1 packs have later generation modules.
    Hybrid Automotive sells used Gen 2 & 3 modules for $50 each but I do not know if they would sell them to put into a Gen 1 pack. @jeff652 would know since that is his company.
     
  18. maverick4u

    maverick4u Junior Member

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    I thought I saw new ones for sale for about $40 on eBay but on closer examination they seems to be used. So from what you are saying, it's not even worth trying to rebuild a battery or get a "rebuilt" (ie used) battery? 2K1toaster have a website or some way to contact him?
     
  19. Prodigyplace

    Prodigyplace 2025 Camry XLE FWD

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    You can either PM him or go to his site here. NewPriusBatteries
     
  20. dolj

    dolj Senior Member

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    Definitely not worth buying a rebuilt (except from a select few that do it properly — read: not cheap) and I would only advocate rebuilding if you did it yourself, with the knowledge that it was a short term measure. If you want a reliable long term solution, go OEM new.
     
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