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How to Encourage Drive Battery Charging?

Discussion in 'Gen 3 Prius Technical Discussion' started by Yaesu, Oct 24, 2019.

  1. Yaesu

    Yaesu Member

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    I live in a residential area so whenever I drive from the main road through the various streets to the house, I must do so at low speed. The engine usually will not run for almost a half mile. I am uncomfortable parking the Prius with the drive battery (sometimes for several days) showing only two bars, and would like to have it charge as I drive the last half mile or so. Is there a way to keep the vehicle from going into the EV mode?
     
  2. Mendel Leisk

    Mendel Leisk Senior Member

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    Pulse and glide might help.
     
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  3. bisco

    bisco cookie crumbler

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    tough situation, any reason you don't want to use the battery? i used to have a similar situation and liked it.

    as mendel states, you can try continually punching the go pedal and letting off completely when you hit top desired speed. then you'll regen until you get to bottom desired speed. rinse and repeat.
     
  4. jerrymildred

    jerrymildred Senior Member

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    You'll take a substantial mpg hit, but the above advice is the only option I can think of. Hit it and coast. Not that there's really anything wrong with parking it with just two bars, even for several days. There is absolutely nothing draining the HV battery when the car is off. The worst that could happen is that it would get even lower if you start back off in hot weather and the air conditioner blasting.
     
  5. Mendel Leisk

    Mendel Leisk Senior Member

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    I find low speed, level streets tend to burn up the charge. It's easy to slip into electric-only, but it'll start to drop the charge fast. If it gets below half charge I'll start doing the pulse-and-glide more.
     
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  6. PriusCamper

    PriusCamper Senior Member

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  7. sam spade 2

    sam spade 2 Senior Member

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    It is not detrimental in any way to leave the traction battery only partially charged.
    Actually, I believe that Toyota recommends that during periods of long "storage".

    And.....you likely live longer if you do not worry about minutiae like that.
     
  8. PriusCamper

    PriusCamper Senior Member

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    I worked on a Honda Hybrid battery pack that sat in a garage for 4 years with voltages in each 8.2v module self discharged down to about the 2 volts range... So, considering the self discharge rates over time, the more you max out your charge if the car sits for a long time, the more likely you'll have enough power in the pack to get the engine running again.
     
    #8 PriusCamper, Oct 24, 2019
    Last edited: Oct 24, 2019
  9. bisco

    bisco cookie crumbler

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    i think lithium likes to store low, and nimh high
     
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  10. ASRDogman

    ASRDogman Senior Member

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    When mine is down to 3 bars and I'm going to stop for the night, I set the criuse for 2-3 miles below the posted
    speed, let it settle, usually it's running on the battery, then press the cruise to increase the speed.
    Almost every time the engine kids in to charge the battery. Depending on how far I go, it will go up
    1-2 bars.

     
  11. PriusCamper

    PriusCamper Senior Member

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    And the new sodium-based batteries they're working on... They actually ship at 0.0 volts, which in terms of shipping costs/safety is one of the main reasons they're developing them
     
  12. PriusCamper

    PriusCamper Senior Member

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    That first year or so I was obsessed with the state of charge of my pack... But then I realized what a crude measure that screen is and how trying to keep my pack in the green bars as often as possible got me worse, not better gas mileage. Besides, after I charge a pack with Prolong charger to 240v = 8.7v per module, even after clearing the memory by disconnecting the 12v, the screen would not be in all green bars, but in blue, even though in reality at 240v it a bar or two above all green bars.
     
  13. ASRDogman

    ASRDogman Senior Member

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    You must have a different screen, I only see green.
    I'm not obsessed with it. It's like a "toy" for me. I don't worry about it too much.
    I try to get the most mpg as I can and rely on how many miles I go and how much fuel I use for those miles.
    The display is just a reference for me. It's usually 2-3 mpg higher than reality.
     
  14. dig4dirt

    dig4dirt MoonGlow

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    We are talking Gen3 here.

    If you want a few more battery bars i.e. 4 bars, half way....
    After parking. apply parking brake (as normal)
    Put left foot on brake, Put it in "D", Put right foot on gas and floor it.
    It will only take roughly 1 min for each bar you want to charge.
    Can let right foot off gas pedal
    Push "Park: button, should be good.

    You can also put in reverse instead of drive if you feel more comfortable.

    This sequence is done for the Dr Prius app to charge to test range of HV battery.
     
  15. PriusCamper

    PriusCamper Senior Member

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    That works with Gen2 Prius too...
     
  16. Grit

    Grit Senior Member

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    My last mile to reach home is 25mph so I push it to 31 mph out of EV and glide. I do it 3 times on average every third of the way. When I park, it’s usually 2 bars w/SOC around 44%.

    Mornings I can get back to 60% after 4 miles at 42mph on the way to town or work.
     
  17. PriusCamper

    PriusCamper Senior Member

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    Battery re-conditioning will improve those numbers... The 2012 battery pack I reconditioned had terrible numbers when I started and once I was done, it had the best numbers I've seen on any pack, almost the same as the numbers I've seen on brand new packs. Learn more here: BU-807: How to Restore Nickel-based Batteries – Battery University and here:
    Prolong Battery Systems. Extending the life of your hybrid. — Hybrid Automotive
     
  18. Grit

    Grit Senior Member

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    Mine averages 63 mpg to the gallon per tank for the last 12 months. How likely will I see an improvement?
     
  19. PriusCamper

    PriusCamper Senior Member

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    I doubt it will improve that at all... But the gain and loss of bars on your dash will be much more stable and your battery pack will likely have a longer lifespan as it ages.