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Battery Vent Tube Questions

Discussion in 'Gen 2 Prius Main Forum' started by davecook89t, Nov 5, 2018.

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  1. C Wagner

    C Wagner Member

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    Does anyone still paying attention to this thread know what the current draw of a Gen 2 prius sitting in your driveway with IG-ON --two clicks of power without pressing brake, not READY mode-- is? Assuming headlights off, sound system off, climate fan off, dome lights off.

    I'm asking because I have twice now brutalized my new smaller 35AH AGM replacement battery, since replacing the tired regular 45AH OEM battery. I am surprised at how quickly the car dies. When working on it 'for a couple of hours', leaving the front door ajar, I brought the voltage (measured at the cigarette lighter) down to 8 before immediately correcting the situation and charging it with a decent 4AH x 8 hour charge. The second time, I must have left the car in IG-ON and walked away. I came back many hours later and it was entirely dead, no voltage registered at the cigarette lighter. It's on the charger now and I'm resolving not to do this any longer!
     
  2. fuzzy1

    fuzzy1 Senior Member

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    Considering that Prii charge rather slowly during driving, with the Gen2 being even slower than the Gen3, there seems to be a persistent issue of a big portion of the Prius fleet being perpetually undercharged, especially for drivers with short or no commutes. Pandemic shutdowns made it worse. You may have started the work with little charge on the 12V battery.

    So any time you might be leaving the door ajar 'while working on it for a couple hours', consider putting it on a slow charger or a battery maintainer for the duration of the work. Or if not safe during the work, do it ahead of time, or disconnect the battery and charge it separately while you work. Or even do it regardless of the door position.
     
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  3. C Wagner

    C Wagner Member

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    Yes, that's a probable scenario. I was also thinking about placing a small (10w?) solar panel on the dash, but I'd need to be able to get to 12v hot all the time, and these cars only have 12 when on Acc mode or IG-ON. If I knew the current draw on IG-ON I could plan better. Yes, I know that I could hook my tester up between the battery and ground, let it sit 30 min and take a current reading... As an additional factoid, I've ordered a handy-dandy battery load tester/analyzer because we all should have one of those, right?
     
  4. davecook89t

    davecook89t Senior Member

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    I'm guessing 40 or 50 milliamps under those conditions, occasionally spiking higher when the brake accumulator pump starts up. At one point, I did have my multimeter bridging the battery's negative terminal and ground on our Gen 2 to test the draw under different scenarios, but with all the different systems that can draw power on these cars, it's hard to get a reliable number. .
     
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  5. TMR-JWAP

    TMR-JWAP Senior Member

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    sitting in your driveway with IG-ON --two clicks of power without pressing brake, not READY mode-

    in this condition, the inverter cooling water pump is running, with no "recharge" being supplied to the 12v battery. Say good-bye to your 12v battery relatively quickly.
     
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  6. C Wagner

    C Wagner Member

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    Yes, this is what I'm interested in. As a tangent, I bought a new OEM inverter pump, which will soon be installed, A non-auto website post mentions that the pump looks to be a 50W device (I think that's about 4.2 12v amps by itself) and would explain why even a larger aux battery like the OEM one (mine is undersized at 35AH,) would be dead quickly...
     
    #66 C Wagner, May 13, 2021
    Last edited: May 13, 2021
  7. gsu13

    gsu13 Junior Member

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    Sorry if I'm re-surrecting a zombie topic, but just bought from a Toyota dealer a TrueStart 00544-21171-325 for my 2005 Prius. Everything fit fine but the vent tube is loose in the circular hole area. I previously had a Bosch Platinum AGM PJB51-440BAGM installed by PepBoys in 2017 (so it lasted 7 years though I think the original lasted from 2005-2017 or 12 years). Maybe Pepboys changed the elbow for the hose but seems odd that the vent doesn't fit the current Toyota OEM battery. There seems to be lots of posts that the vent is not needed or just find a cheap elbow from HomeDepot, but would the OEM vent hose 28885-21010 even fit? I supposed I'll just ask the dealer parts dept but they're closed right now and I'm deciding whether to return to the dealer or just go to a hardware store, so thought I would ask here
     
  8. ChapmanF

    ChapmanF Senior Member

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    Maybe the worst thing that can happen at the hardware store is you don't find an elbow that'll fit. If you do find one, problem solved!
     
  9. pasadena_commut

    pasadena_commut Senior Member

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    Wrap it with teflon tape until it is fat enough to stay in the hole? I would be worried though it might work its way out, since teflon doesn't generate much friction.

    This is a little gross, but maybe just glue it in place with a little rubber cement or something like that? That would seal the tube to the hole, and grip, but not so tightly that it couldn't be pulled out, probably by hand, but certainly with pliers. Just don't get any glue in the battery.
     
  10. TMR-JWAP

    TMR-JWAP Senior Member

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    I think this is probably a good path. A little dab of silicon or rtv would make short work of this problem.
    I seem to remember the last 12v battery I bought came with a new elbow.