12 volt battery?

Discussion in 'Gen 5 Prius Main Forum' started by Robmoo, Nov 17, 2022.

  1. Robmoo

    Robmoo Junior Member

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    Did they get rid of the 12volt battery? In my Gen 4 they stuck it under the hood which was a BIG mistake.

    Will I need to buy a 220 charger to get that 37 miles per charge? That would take me to work and back.
     
  2. bisco

    bisco cookie crumbler

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    it is back in the hatch again, from what i've read

    you get the same range with 120 or 240, 240 is just a faster charge
     
  3. Trollbait

    Trollbait It's a D&D thing

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    Level 1 should be fine. The current one with 25 miles takes under 6 hours to charge at that rate. If Toyota didn't put in a faster charger, the new one may take 9 hours.
     
  4. JMRanger

    JMRanger Junior Member

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    That would only work on outlets rated for more than 15 amps, and pop the breaker for everyone else...
    That being said, I'm really curious to see if they allow for more than 3.3kW on level 2. My guess is that they don't.
     
  5. JimboPalmer

    JimboPalmer Tsar of all the Rushers

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    Traditionally, Toyota powers up with the 12 volt battery to do a multitude of safety checks before allowing the HV battery to power anything. I would be amazed if they decided the safety checks were unneeded.
     
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  6. Trollbait

    Trollbait It's a D&D thing

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    Hybrids and plug ins disconnect the traction battery when powered down. This is to unenergize the high voltage components. Of course it means you need another energy source to boot up the computer, and reconnect that battery. In most cases, that is a 12V battery. The Ioiniq and Niro hybrids have a subset of the traction pack that feeds the DC to DC converter to supply that start up 12V. What other safety checks could that setup not perform?

    I don't know if Hyundai eliminated the 12V starter battery in later hybrids. The Ioniq Electric used a 12V battery though. Presumably so all the traction pack was available for range. @Tideland Prius does your EV6 have a 12V battery?
     
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  7. Tideland Prius

    Tideland Prius Moderator of the North
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    Yes it has a 12V battery under the hood. It looks smaller than normal (reminds me of the Gen 2/3 batteries) but I don't think it's AGM.

    Curiously, North American versions have a 12V battery charging feature that uses the HV battery to charge the 12V battery even while parked. An orange light on the dash will indicate if the 12V is being charged, and thus the HV wires are live.
     
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  8. Trollbait

    Trollbait It's a D&D thing

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    Teslas do that. They will wake up to top off the 12V when it gets low. It's one of the vampire draws when the cars are parked unplugged. Charge loss is probably better than not starting.
     
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  9. Tideland Prius

    Tideland Prius Moderator of the North
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    The problem is, what is the vampire drain in the EV6/Ioniq5? We don't have sentry mode (like the Korean market). Connected services? (I guess for the app to ping the car?)

    Also, the car gives a dire warning that the battery will drain very soon after you go into ACC mode (I'd say within a few minutes). It's easy to trigger that 12V battery charging light which makes me worried that Kia/Hyundai chose the minimal capacity 12V possible to save on weight or cost.
     
  10. Myself248

    Myself248 Junior Member

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    If you have fewer amps available, then just configure your EVSE to tell the car there's fewer amps available. The J1772 spec allows down to 6A. Build/buy an OpenEVSE, they're nice and configurable, or see if your other favorite L1 cheater-cord is configurable.

    Having done so, the car's on-board charger _must_ respect the current limit indicated in the EVSE's pilot signal. It's a mandatory part of the spec. Charging will be somewhat less efficient because the car's overhead-load will be active for longer while the battery trickles up to full, but that shouldn't be such a big deal.
     
  11. Trollbait

    Trollbait It's a D&D thing

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    Maybe they are limiting draw on the 12V to limit wear:cautious: On the saving cost angle, it could be a true starter battery they have in supply, instead of a deep discharge model. Those won't last as long while discharging.

    When I read about the Tesla 12V treatment, sentry mode may not have been a thing. It was back when parked Teslas losing range was a news item. Owner with one and Leaf left them unplugged for week. The Tesla had the expected range loss. The Leaf wouldn't start because the 12V had died. Manufacturers installing an undersized battery isn't new. It used to resulted in the above like the Leaf, or replacing the battery much sooner than it should.

    What were you doing in ACC mode? My Subaru salesperson warned me to have the engine on when playing with the multimedia and car settings. It isn't like you'll be burning gas.
     
  12. pakitt

    pakitt Senior Member

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    Could somebody please explain me the overall conversation happening about the 12V battery existence and location?
    Why is it so important of a topic for some? I know the Prius has one for several technical reasons, but I don't really care if my car has one and where it is, as long as I can turn the car on and drive from A to B. How that is achieved, with a 12V battery or not, I honestly don't care.
     
  13. Trollbait

    Trollbait It's a D&D thing

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    The Ioniq and Niro hybrids simply don't have a 12V. Dedicating a small portion of the traction pack to those duties isn't difficult, and it eliminates a maintenance item the owner needs to deal with. Without using NiMH, Toyota could have chosen to do the same with the gen5.

    There are pros and cons to front or rear for a lead acid. Most cars have more weight on the front axle. Moving it to the rear shifts a lead brick's worth of weight for better balance. BMW does that for driving performance. Early Prii did it more because there wasn't space under the hood. Then in theory, the battery isn't exposed to engine bay heat, so should last longer.

    The downsides of putting the battery in the rear is in access. For a battery not big enough to turn over an engine, not a real big deal. More an issue if the car needs a jump, though there could connection points under hood for that. It also needs to be a vented model when in a hatchback or wagon. Not needed when in a trunk that can't be opened to the cabin, but that is rare these days. The venting generally means the replacement will be higher price. While the conditions under which it happen are rare, an improperly vented lead acid battery can kill you with poison gas.
     
  14. ChapmanF

    ChapmanF Senior Member

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    If you are thinking of modding the car with added electrical stuff in the cabin, you might be happy when the battery isn't out under the hood, so you don't have to bring new cables through the firewall.
     
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  15. Trollbait

    Trollbait It's a D&D thing

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    The access and venting requirement could lead to issues in the case such mods require the battery to be 'upsized'.
     
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  16. ChapmanF

    ChapmanF Senior Member

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    There are considerations either way. If you have in mind a mod like a power inverter, and you want to keep its 12 V supply wires as short as you can, with an underhood battery you might be tempted to mount the inverter out there too, not a friendly environment for electronics. With the battery indoors you can have the added stuff indoors too, without needing super long 12 V wires.
     
  17. Tideland Prius

    Tideland Prius Moderator of the North
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    Force of habit. 18 years of Prius and “thou shalt not idle” to save battery as emissions. I do turn the car on now or go into Utility Mode so that I don’t get dinged on the Consumption History.
     
  18. bisco

    bisco cookie crumbler

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    where did the under hood space go that housed the gen4 12v?
     
  19. Trollbait

    Trollbait It's a D&D thing

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    My guess is into the larger wheels and maybe a sharper sloped hood.
     
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  20. Terrell

    Terrell Old-Timer

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    Really? Which versions have that? I don't think Gen 3 does. If it does, I've never seen the orange light. And I have run the 12V battery down to dead early on, when I left the dome light on all night one time.