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Is it fine to drive PHEV at 0% charge?

Discussion in 'Gen 5 Prius Main Forum' started by LindaOwnsAPrius, Aug 7, 2023.

  1. LindaOwnsAPrius

    LindaOwnsAPrius Junior Member

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    Coming out of a 2012 Prius C (as the original owner) and into a 2023 Prius Prime — I’m simultaneously overjoyed & overwhelmed.
    As an apartment renter w/o a garage in San Francisco, I don’t have the option to charge from home so I’m reliant on public charging stations. The infrastructure is decent in the city, but not great…so, after a few days of my daily 10 mile work commute, I’m down to 0% charge. Here are my questions:

    * is it fine to drive a PHEV even if the battery is not charged? Can I assume that with a combustion-assisted electric engine, the battery always has some energy stored away? Could I drive for weeks at 0% and not cause any harm to the engine?
    * I’m not sure which drive mode would conserve the most electricity until I can- hopefully- find a rented parking space with EV charging. Right now, I’m waking up at 6am Saturday mornings to snag a public charger before the masses descend on the few available L2 stations.

    thanks in advance to all you kind-hearted folks on this forum. I really appreciate the help!
     
  2. Numtini

    Numtini Member

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    It's fine, but you could have saved a few thousand dollars by just going with a Prius HV.
     
  3. LindaOwnsAPrius

    LindaOwnsAPrius Junior Member

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    yes, for sure.. but I did a One-Payment lease for 24 months to give me the opportunity to (1) 'own' the car for 2 yrs to see if it's a good fit for my lifestyle and (2) I may have a home garage with EV charging capabilities before the lease expires, in which case, I'd use the EV mode daily for work commutes.
     
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  4. bisco

    bisco cookie crumbler

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    you can drive it forever without plugging i. no harm, no foul. thousands used to buy plug ins in cali for the hov sticker, and never plug in.

    no need to worry about conserving energy. it's just a regular prius when you run out of wall charge. that's how plug ins were designed.
     
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  5. tovli

    tovli 2023 Prius Prime replaced 09 Prius

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    Perfectly fine - The Prime is designed to drive with the most efficiency it can muster given the circumstances.

    Yes, If the SOC is showing ----%, the car will use the power reserved to start with the electric motor for backing, or from stop lights and parking, then the engine will take over. You will see both the HV Mode and EV driving icon light up when the car decides it should use some of that reserve for maximum efficiency.
    Reserve.JPG
    Absolutely. The car will optimize with what you give it to work with. If you don't have grid power, (or regenerated power from a long descent from Tahoe to Sacramento for example) the car will still give you some of the best hybrid vehicle MPG available, with no harm whatsoever.
    This is a more complex question to answer because you have varying costs for both grid power and gasoline, and the miles per kWh and miles per gallon depend on how you drive, what the weather is, and the terrain you have to travel.

    In general the car is designed to prefer EV driving when power is available, but the manual does suggest manually forcing HV mode for extended highway driving to save available EV Mode power for stop&go driving on the way to the high speed segments and afterwards.

    When gas prices are low and electric rates are high, charging may not save money, (but the thrill of EV driving may be worth the extra cost to you. EV driving is very rewarding emotionally to me, but I am also very lucky to have low grid power cost.)
     
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  6. tovli

    tovli 2023 Prius Prime replaced 09 Prius

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    You should ask around for the nearest charge point to your work place, and investigate if there are any free charge points convenient to you.

    While the Toyota phone app is a mess, it does have a find nearby charge stations but does not give the charge costs. Using chargepoint.com -> find stations ->San Francisco -> filter free: shows a bunch, and without the free filter will tell you the rates for their network charging points.

    To use the free charging at ChargePoint stations, I had to request an "Extension" to my local power company's free charging program by entering my tag. I was approved in minutes and tried a free charge at a nearby park. Free charging has its complications and may not result in any savings, but it was fun to experience. BTW, I skipped entering my credit card, since I only intend to charge when it is free.
     
    #6 tovli, Aug 8, 2023
    Last edited: Aug 8, 2023
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  7. LindaOwnsAPrius

    LindaOwnsAPrius Junior Member

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    wow.. thank you for this detailed reply and the tremendously helpful information. EV driving is incredibly satisfying for me also.. it even sounds like the car is saying : weeee! as opposed to the drone of the the fuel engine.
     
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  8. Trollbait

    Trollbait It's a D&D thing

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    It's fine using it just as a hybrid. Long term, it may not be the best for the battery, as the charge level will be sitting below where Li-ion is happiest. By long term, I mean life of the car, and there are other variables that affect battery life. If you are putting a charge in once in awhile, I wouldn't worry.

    For the second question, depends on your drive. If there is portion of highway driving with higher speeds, put in HV mode for those miles. This will stretch out the EV miles at lower speeds. Otherwise, just use EV Auto. The car will go into hybrid operation more often than in EV mode, that will extend the time between charges.

    If asking about the drive modes(Eco, Normal, Sport), those don't matter much. You can drive just as inefficiently in Eco as in Sport. Eco might make changes to the HVAC operation to reduce energy use, but for the most part, pick the one you find comfortable.
     
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  9. LindaOwnsAPrius

    LindaOwnsAPrius Junior Member

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    thank you.. this clarifies the very things I was concerned about


    yes, I've used two ChargePoint stations in the past week. Unfortunately, the app doesn't indicate that they're often reserved for "employees only" or are located in public parking garages with a premium hourly cost for parking while charging. I did find a EV charging station in one of our city's national parks that had free parking & hiking trails nearby. That's the one I plan to use regularly, but I'm not the only one who knows about it, so timing is definitely everything once it shows "available" in the ChargePoint app : )

    thank you bisco. This really is the answer I hoped to hear

    thank you! I wasn't yet aware of the EV Auto mode; that sounds like the best mode for needs right now.
     
    #9 LindaOwnsAPrius, Aug 8, 2023
    Last edited by a moderator: Aug 8, 2023
  10. Exerted

    Exerted Member

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    Do you mind saying why you went with a lump sum lease payment? I ask because if you total your car tomorrow, you're not going to see a cent of that back. Insurance companies don't send a check to the car renter for the value of the car.
     
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  11. tovli

    tovli 2023 Prius Prime replaced 09 Prius

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    I thought I saw a way to get on a waitlist for a charger
     
  12. LindaOwnsAPrius

    LindaOwnsAPrius Junior Member

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    hummm, I just double-checked the ChargePoint app, which I have filtered to show only L2 charging stations.... I'm not seeing any local charging stations that have the waitlist option. I have seen Tesla & fast charge stations with the option to get on a waitlist, tho.
     
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  13. LindaOwnsAPrius

    LindaOwnsAPrius Junior Member

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    :eek:.... let's hope such a thing doesn't come to pass.
    But, it made sense ...in several ways .... for me to go this route. I'm not going to go into the details on this public forum (y)
     
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  14. BiomedO1

    BiomedO1 Senior Member

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    Welcome Linda,
    Driving the car around in HV isn't an issue, the on-board computers will automatically adjust. The only thing I can add is, allow for a little extra spacing - while cutting across traffic or merging. When the HV battery portion gets really low, there are slight delays between gas pedal response and the car actually jumping forward. You can mitigate this issue by placing the car in either 'normal' or 'power' mode - NOT eco mode. If you get used to driving the car in EV mode and it suddenly drops into HV mode, while making a left turn - across traffic; You'll get 'honked at' if not hit.... Safe motoring.......

    Hope this helps.....
     
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  15. LindaOwnsAPrius

    LindaOwnsAPrius Junior Member

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    Hi and thank you so much for this explanation. Truth is, I became accustomed to using eco mode with my 2012 PriusC & so I’ve been doing the same now, with this PHEV car. … but now I understand that eco mode directly relates to the function of the accelerator pedal… & my need to have a more reliable response in that regard means I should be either in normal or power mode.
    I’ve definitely been educated in the past 48 hours, thanks to this forum, and I’m sincerely grateful for everyone’s helpful advice :love:
     
    #15 LindaOwnsAPrius, Aug 9, 2023
    Last edited: Aug 9, 2023
  16. Numtini

    Numtini Member

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    I remember that lag from when we test drove a 3rd gen prius (why we didn't buy one), but I have not experienced this in our 23 Prime and I've done about a thousand miles in HV between vacations and running HV for the 600 mile break-in.
     
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  17. tovli

    tovli 2023 Prius Prime replaced 09 Prius

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    In the 700 mile trip home with my 2023 Prius Prime XSE (with ----% showing the whole trip), the blue HV battery reserve section never lost more than the one tiny pixel separator getting on the highway, which was quickly restored as I drove. I was watching that especially to gain understanding of the car's reserve management.

    Reserve.JPG

    In my 2009 Prius (non-prime) the battery was allowed to get down low to two bars, but the 2023 Prime seems to maintain the reserve at its maximum.

    I did not detect any lag in the power curve in the 2023 Prius Prime XSE (temps were 95F plus the complete trip).
     
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  18. Trollbait

    Trollbait It's a D&D thing

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    In addition to state of charge, battery temperature also can lead to such behavior. Which has improved with the generations.

    With the 2L, I don't expect it to be an issue in the gen5.
     
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  19. Numtini

    Numtini Member

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    I've seen the same in the 2023. Once it gets to the zero-ev-range, it pretty much maintains the level.
     
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  20. Mr.Vanvandenburg

    Mr.Vanvandenburg Senior Member

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    If the station is occupied some Chargepoints have a 120 outlet secondary option. Full ev’s tend to scoff at 120, making it available. There has to be parking within reach. A free park charge point with hiking nearby would be great to use the 120 outlet. The one I often use is behind a metal door on the post that unlocks after authorization. Free. I don’t have to hurry back either as the fast charging actually fills it too quick. Plus rarely anyone uses or even knows about the 120.
    You can drive it without charging but the added energy from external charging is the whole idea to get a Prime I think.
    Where I live pay Chargepoints and the other companies charge a lot for the electricity, usually near 40 cents per kwh. I don’t go to them can charge at home for less.
     
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