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Featured Parking my hybrid in the sun heat

Discussion in 'Toyota Hybrids and EVs' started by Bog1992, Apr 13, 2021.

  1. Mendel Leisk

    Mendel Leisk Senior Member

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    So far so good, albeit scant comfort for 3rd gen owners.
     
  2. Trollbait

    Trollbait It's a D&D thing

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    By this time, I would think all cars are using 'smart' alternators that vary their load on the engine. IIRC, Honda started using them in the 1990's.
     
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  3. fuzzy1

    fuzzy1 Senior Member

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    Dumped where?

    Or simply not generate excess in the first place? That is what voltage regulators are for.
     
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  4. ChapmanF

    ChapmanF Senior Member

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    Vibrating-reed voltage regulators varied the engine load for decades before that.
     
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  5. Isaac Zachary

    Isaac Zachary Senior Member

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    This is incorrect. In all charging systems in all cars, whether they be high voltage hybrid, 48V, 24V, 12V or 6V charging systems all regulate the charging current and voltage. When the battery gets full, reaching a certain voltage, the current slows down, and the higher the voltage the less the current, until current completely stops entering the battery.

    There is no place where the extra electricity is dumped. Even a 12V system. Those produce hundreds of amps at around 14V. That's thousands of watts, or several kilowatts. Think, you'd need a few heaters, like the kind of space heaters used to heat rooms in houses, that would all be on at full blast in order to "dump" the extra electricity of an alternator if alternators really didn't have a way of regulating the charge current.

    As for hybrid systems, it's been my experience that when engine braking the car also keeps regenerative braking until the battery is "full." Then current is cut off and the car increases engine RPMs to make up for the lack of regenerative braking when you have a full battery.
     
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  6. Bog1992

    Bog1992 New Member

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    The last couple of days was pretty hot under then sun, around 95 degrees F (35 in celsius).

    I noticed a couple of things.

    1. One time when I left the car parked with 5 bars for 2 hours under the sun, then when I started the car, there were only 3 bars.

    2. It seems that when the car sits under the sun, the battery doesn't have that much juice in it, it drains pretty quickly when I drive it.

    Is this normal behaviour?

    Thank you!
     
  7. Kramah313

    Kramah313 Active Member

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    For item 2, the reason for this is probably the A/C. The traction battery powers the A/C directly, and when the A/C is running at max the load from it alone can exceed 10 amps, which is like a third of what the car is going to pull from it to move most of the time. So yeah, I would say that’s probably normal.
    I haven’t seen issue 1 happen to mine though. But that gauge is strange too. I have a scan gauge with a percentage number for that, the in car battery gauge is not linear. The top two bars encompass like 15% while the middle ones are like 5%. It’s possible you were right at the edge of the highest one when you parked.
     
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  8. alanclarkeau

    alanclarkeau Senior Member

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    I wouldn't think that (1) should happen - but as another reply says, the gauge isn't really accurate. It's often that temperature here, and I've never noticed that. The A/C can use a bit of power if the inside is steaming hot to pull the temp down.
     
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  9. Trollbait

    Trollbait It's a D&D thing

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    I don't know of any hybrid that doesn't physically disconnect the battery. Any charge loss would be to self discharging then.

    My understanding is that heating the battery would increase the effective charge as the chemistry can happen at a quicker pace.
     
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