I have an idea...

Discussion in 'Gen 5 Prius Accessories and Modifications' started by Paul Gregory, Sep 21, 2025 at 1:59 AM.

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  1. bisco

    bisco cookie crumbler

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    did you get a jump pack with a dead battery override switch?

    the battery has to close relays as well as boot computers. idk how much current is needed.
     
    #41 bisco, Sep 22, 2025 at 9:08 PM
  2. ChapmanF

    ChapmanF Senior Member

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    It's easy to overlook a lot of the draws on the 12-volt battery in the process of going READY.

    The process starts out the same as IG ON, with power to all the car equipment that gets power in IG ON. That includes a couple dozen computers, the instrument panel, some pumps, and so on, also extra things like the wipers or seat heaters if they were left on when the car was shut off.

    As soon as the HV control ECU has completed its checklist and decided it's ok to close the battery relays, the DC/DC converter comes online and takes over supporting those loads, but they were all on the 12-volt battery for the second or so before that happens.

    The battery relays aren't an especially significant part of that load, just another small part of the total.

    In my generation, the brake accumulator pump can be one of the larger loads active during that time. But I'm not positive gen 5 does the brakes the same way.
     
    #42 ChapmanF, Sep 22, 2025 at 9:22 PM
  3. bisco

    bisco cookie crumbler

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    that must be why my 12 had auto off seat heaters
     
    #43 bisco, Sep 22, 2025 at 9:23 PM
  4. ChapmanF

    ChapmanF Senior Member

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    oh, they changed that? in my '10 the seat heater switches are plain mechanical switches. on is on.
     
    #44 ChapmanF, Sep 22, 2025 at 9:25 PM
  5. Paul Gregory

    Paul Gregory Senior Member

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    I never use seat heaters. They make my butt itch.
     
    #45 Paul Gregory, Sep 22, 2025 at 10:09 PM
  6. Hayslayer

    Hayslayer Member

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    How many people need to tell you that YATAH before you believe it?
     
    #46 Hayslayer, Sep 22, 2025 at 10:20 PM
  7. Paul Gregory

    Paul Gregory Senior Member

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    It seems that draining the battery intentionally is not so easy. I left the ACC on, but when I came back an hour later it was turned off and the battery was at 12.6 volts. The booster however, came on when I plugged it in, as indicated by a green light.
     
    #47 Paul Gregory, Sep 22, 2025 at 10:22 PM
  8. Paul Gregory

    Paul Gregory Senior Member

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    I'll believe evidence. Even a consensus can be wrong.
     
    #48 Paul Gregory, Sep 23, 2025 at 9:56 AM
  9. Paul Gregory

    Paul Gregory Senior Member

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    I have a DC current meter, so I could measure it if I want, but I know it isn't much because it's not running a starter motor, and all the times I've boosted the car, it never showed any signs of passing high current. At any rate, I'm sure the starter demands of the Prius are well within the capacity of any booster pack.

    Having said that, it depends on the amount of charge left in the 12V battery. It's never been dead flat; it's always somewhere between 6V and 11.6.
     
    #49 Paul Gregory, Sep 23, 2025 at 10:27 AM
  10. Paul Gregory

    Paul Gregory Senior Member

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    I'm only here to share and acquire ideas about my Prius, and share my past experience. But I never counted on the level of trolling that I've seen here. All forums have some trolling of course, and it can usually be dealt with by ignoring, but this stuff is on a whole new level.

    You get judged on things you never said, so it's impossible to ignore. Unfortunately it looks to the mod that I am the troublemaker. Like I said, trolling on a whole new level.
     
    #50 Paul Gregory, Sep 23, 2025 at 12:59 PM
  11. bisco

    bisco cookie crumbler

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    they must have. was 12 a refresh?
     
    #51 bisco, Sep 23, 2025 at 1:31 PM
  12. bisco

    bisco cookie crumbler

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    i'd love to see pics of your setup. right now my pack is in the hatch, under the floor. probably a mistake since i'd have to crawl back there, try to lift the floor from the opposite end, and fish around for it.
     
    #52 bisco, Sep 23, 2025 at 1:33 PM
  13. ETC(SS)

    ETC(SS) The OTHER One Percenter.....

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    Generally speaking, it's a one troll per bridge limit.

    If you think everybody else in the thread are the trolls?
    Um......you probably have it the other way around. ;)

    Go outside and touch some grass and stop giving so many people the power to irritate you.
    It sounds like you've mitigated whatever happened to your electrical system that's causing your problem.
     
    #53 ETC(SS), Sep 23, 2025 at 1:34 PM
    Last edited: Sep 23, 2025 at 1:39 PM
  14. ChapmanF

    ChapmanF Senior Member

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    It was. Also, didn't you have a PiP? Didn't that get seat heat switches with hi and lo settings? Mine are just on/off.

    I'm pretty sure I looked up the PiP seat heater wiring diagram once upon a time for a thread around here. Maybe it's still around. I don't remember seeing anything about them being auto-off (but I guess that could have been an internal feature of the switch not explicitly shown in the diagram).
     
    #54 ChapmanF, Sep 23, 2025 at 1:37 PM
  15. bisco

    bisco cookie crumbler

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    yes, hi/lo. just a rocker as i recall, and went off when you powered down.
     
    #55 bisco, Sep 23, 2025 at 1:42 PM
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