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Prime performance when EV battery is depleted

Discussion in 'Prime Main Forum (2017-2022)' started by satsuke, Apr 11, 2021.

  1. bisco

    bisco cookie crumbler

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    apparently, the o/p's experience was different
     
  2. fuzzy1

    fuzzy1 Senior Member

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    Many other members here have had the same Gen3 'no turtle' experience that I had at this location. While o/p's experience there seems common -- but not universal -- among Gen2 owners, it seems abnormal for Gen3.
     
    #22 fuzzy1, Apr 12, 2021
    Last edited: Apr 12, 2021
  3. bisco

    bisco cookie crumbler

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    yeah, who knows how many in total have trouble in mountainous territory?

    but the real question is, if o/p wasn't happy with the gen 2 or 3, will they be happy with prime?
     
  4. satsuke

    satsuke Junior Member

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    "Fully discharged" meaning its no longer drawing on the battery for propelling the car forward.

    In my Pike's Peak example, I made it up past the tree line before the traction battery was depleted enough where it was drawing ICE power to charge the battery.

    I didn't say turtle mode, but it is apt, because at that point it couldn't get above about 10mph due to no battery assist and some limitations of the drivetrain.

    For my needs, I'd probably keep the car in HV mode when on road trips, since it is unlikely I could charge the car fully during the trip itself

    It is of course possible to deplete the batteries enough where it won't actually move the car as I found out recently when my current 2012 Prius got an ICE fault that lit up the big red triangle light and the message to pull over as soon as possible. (Which ended up being a throttle position sensor issue, I ended up clearing the codes and getting to a safe destination before having it serviced
     
  5. Trollbait

    Trollbait It's a D&D thing

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    If they weren't happy with the gen2, why get a gen3?
    I took the post has just looking for info.
    I don't think you'll find a turtle mode mentioned in official sources, but the gen1 had a turtle shaped idiot light come on when the battery was fully discharged. Following generations just got better, and the majority of owners never experience turtle mode.

    Did you always experience turtle mode at that point? I wondering if aging batteries played a part.

    Saving grid charge in the battery for mountain climbs should mean this never being an issue with the Prime.
     
  6. Froglegs

    Froglegs Junior Member

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    I didn't know the battery had pleats! If so, depleating could be a serious condition.

    Sorry, I can't help myself.
     
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  7. bisco

    bisco cookie crumbler

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    a question for the o/p?
     
  8. Trollbait

    Trollbait It's a D&D thing

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    He was the OP;)
     
  9. bisco

    bisco cookie crumbler

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    you quoted both of us, but you asked me why he bought a gen3
     
  10. Trollbait

    Trollbait It's a D&D thing

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    Thought it was clear which portions were to whom.
     
  11. bisco

    bisco cookie crumbler

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    which is why i was wondering why you thought i might know
     
  12. Trollbait

    Trollbait It's a D&D thing

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    It was rhetorical. If they weren't happy with a gen2, they likely wouldn't get a gen3. They were obvious happy with the cars overall, or wouldn't be considering a Prime.
     
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  13. bisco

    bisco cookie crumbler

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    thanks, i'm easily confused :oops:
     
  14. Henrik Helmers

    Henrik Helmers Active Member

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    When you use up the EV range, the Prime will behave like a regular Prius (which is surprisingly good). If you are planning on climbing an exceptionally steep hill, switch to HV mode early, to save battery power for the climb. Or use CHG mode in advance to build up a bit of reserve.

    I imagine the Prime is reserving ~10% of the battery capacity for HV mode. If you leave 10% of the EV range portion you will double that reserve.

    Going up reasonable hills I have never experienced depletion, but I notice changes to the engine load when going up the hill depending on where the car is in the HV cycle. If it is trying to replenish battery reserve the load will be higher. If it is currently discharging the engine load will be lower.
     
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  15. PiPLosAngeles

    PiPLosAngeles Senior Member

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    Experimentation suggests that using EV for uphill travel is less efficient than using HV. If you drive an identical route multiple times that's long enough to exhaust your EV range, try alternating between using EV for uphill sections and HV for downhill and/or flat sections, and vice versa. You will find that you use significantly less gasoline using EV for downhill and flat sections (even at highway speed ~70 mph) than the other way around.
     
  16. Henrik Helmers

    Henrik Helmers Active Member

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    I don't disagree. My understanding is that the OP is asking about what happens if you are in HV mode, and ask for more power than the ICE can deliver. This will then drain the battery until empty, and the engine will then have to replenish the battery while still overloaded, which will force the car to go slower.

    In that scenario it makes sense to save a bit of extra battery to be prepared. I don't know how common that scenario is.
     
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  17. satsuke

    satsuke Junior Member

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    FWIW, in reading through this and elsewhere, I learned of the "Hold and charge" function on the prime where you can recharge the battery pack through something more than regenerative braking .. that and the ~15% battery holdback so that it operates like a non-prime prius.

    The turtle mode above was an extreme example of a long uphill assent where I had to rely on the ICE only.

    The only other time I've had the battery discharge that completely was recently when the ICE faulted / fail to start and I had to drive it ~1 mile to the dealership (and play a game of clear codes -- charge battery, move a bit before fault and repeat. FWIW it was a throttle body position sensor fault.
     
  18. Salamander_King

    Salamander_King Senior Member

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    IMHO, the word performance is never a term I use to describe the Prius, including Prime, driving characteristics. Not that I have ever owned or driven so-called performance cars, all the eco-oriented fuel-efficient cars with small 4 cylinder engines I have had felt underpowered on a steep climb. My feeling is that PP performed worse than my previous Gen3 in those situations (HV mode uphill), due to heavier weight. That being said, I never felt that Gen3 nor the PP were inadequate for any of my driving conditions. But, I may feel differently if I lived in Colorado for example.
     
  19. PiPLosAngeles

    PiPLosAngeles Senior Member

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    I routinely drive mountain highways in the PP and don't feel as though the car is under-powered. I don't notice any perceptible difference from my 2012 PiP.
     
  20. m8547

    m8547 Senior Member

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    On long hills, the engine will supply all of the power to drive the car. I watch the engine and battery power output on Hybrid Assistant, and in this situation the battery power goes to nearly zero (not being charged or discharge) and the engine supplies whatever is needed. I've seen it sit at 40kW (which is usually around 4,000 RPM) for several minutes at a time with no problems. Even if you need to accelerate moderately while climbing a hill, it will just increase the engine power before calling on the battery to help. If you need to accelerate quickly while climbing a hill, then maybe you bought the wrong car.

    I have yet to find a hill that requires more power than the engine can deliver to maintain a constant speed. But I am guessing if there are any problems it would be at low speeds (like 25mph or less) since it feels like the engine is less effective then.