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EV switch right application

Discussion in 'Gen 2 Prius Accessories & Modifications' started by maggieddd, Jan 15, 2006.

  1. maggieddd

    maggieddd Senior Member

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    I know EV switch questions come up all the time. I have one little question which I didn't find answer to by searching.
    Here is a situation:
    I am using EV switch and I managed to do my whole trip around the city in the electric mode only. When I finish the trip my battery is very low (purple bars). The car is going to stand in the cold for hours so the engine will be very cold when I am ready to use the car again. I know it will use gasoline to charge the battery when I drive it again, but since the engine is cold it will use gasoilne anyway to warm up. So, whether the battery would be completly charged or comletly discharged the gasoline has to be used to warm up the engine. I assume while the engine is warming up it also charges the battery, am I right? And if so, the hit on my mpg shouldn't be significantly higher in this case. Am I right or am I completly wrong?
     
  2. priusblue

    priusblue New Member

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    I'm interested in this too - I would think that would be true - I mean the engine will be running a little more than usual simply to warm up - and will likely generate extra energy to charge the battery in the process. I just ordered by EV kit from coastal tech, and was thinking it would be ideal for short trips around town between my usual long commutes where the battery typically gets charged up all the way.
     
  3. maggieddd

    maggieddd Senior Member

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    I am in the same situation. I drive to work 50 miles, the battery gets fully charged and a lot of times stays on green. Then on my lunch break I do short trips around the town and then the car sits on the lot for 4 hours or so again. Then I drive 50 miles again.

    Also, I am trying to decide whether I should get the OEM switch or the one crom Coastal. Is there any difference other than the price?
     
  4. TonyPSchaefer

    TonyPSchaefer Your Friendly Moderator
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    Yeah, I finish my drive home with a drive through suburbs ~25MPH. I stealth all the way home and try to discharge as much battery as possible. Like Maggie, I figure that the car will warm up in the morning and recharge the battery. I would like to think that this is an intelligent use of stealthing/EV.

    But Maggie, I'm a bit confused. In your original post, you start with "I am using EV switch . . ." and then follow it in your reply with "I am trying to decide whether I should get the OEM switch or the one crom Coastal." Do you have the switch yet?
     
  5. maggieddd

    maggieddd Senior Member

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    Tony, this was just a hypothetical scenario I was describing. I don't have a switch yet. I am trying to decide whether I shold get one or not.
     
  6. jwe8f

    jwe8f New Member

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    I believe the car tries to use the battery as much as possible during warm-up, theoretically to keep the load off a cold engine. I believe this because as I drive through my subdivision with my motor running in the morning, I watch the battery bars drop. It is clearly in EV mode with the engine running.

    If you start out in the purple, I would assume the engine will pick up the slack. However, since I believe Toyota is trying to keep the load off the engine when it's cold, I would also think adding a load would reduce your gas mileage and increase your emissions. For that reason I do not deplete my battery more than halfway at the end of a trip.

    EV switches are not usually good for 'trips', unless they are very short. The best uses are shutting down your engine when you enter your subdivision at the end of your trip, or to shut off the engine when you are driving across a parking lot or waiting in a fast-food line. I have used it for a full trip, but the trip was only a block or two long.

    You should really think of an EV switch as a way to keep your mileage from DROPPING under certain circumstances, rather than a method of raising it.

    I love my EV switch, but it has nothing to do with gas savings. I love the control it gives me over unnecessary use of the engine, but mostly I love impressing my neighbors and co-workers... :D
     
  7. priusblue

    priusblue New Member

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    The reason I'm getting the coastal one is b/c I have a 2006 and this post
    http://priuschat.com/index.php?showtopic=14252&hl=ev+mod
    says the OEM switch won't work. If you have a '04 or '05, I'm not sure which one is best. I like the idea of having the switch on the cruise control bar that the coastal one has, instead of the button. Seems like easier access. My honda had the cruise on/off switch where the EV button should be and I found it very inconvenient.
     
  8. maggieddd

    maggieddd Senior Member

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    I've got '05 Prius. any other characteristics of OEM vs. Coastal switch? I don't know, I think I would rather have it as a separate swich instead of cruise control, but I am not sure.
     
  9. Tideland Prius

    Tideland Prius Moderator of the North
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    well Coastal's one is very easy to install (except for that orange pin that everyone complains about). Just make sure that orange pin is FULLY inserted.

    The OEM one requires both sides of the dash to be removed and to me, that's more complicated especially with the power button and shifter. Also, I believe soldering is required?

    I'd like to have the OEM switch but the installation is difficult for me.
     
  10. maggieddd

    maggieddd Senior Member

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    thanks, maybe I'll go for the Coastal switch

    how is the warranty issue? Do you void it or not by installing the EV switch?
     
  11. EricGo

    EricGo New Member

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    Maggie,

    I am also considering the EV switch. I can only share my reasoning, but no experience to back it up:

    When the ICE is running to heat up, the power not sent to the wheels is sent to the battery. So the losses are related to transfer to battery and out, rather than ICE use per se. If you start the day at four bars, and go up to seven, or if you start at 2 bars and go up five, I don't see the difference.

    HOWEVER, if your warmup leads to a full battery before the ICE is finished, then the ICE extra power output is wasted to heat, with no where to go.

    I live at the top of a hill, and often spend most of my first 10 minutes driving downhill, so I see the full battery very often, and almost daily in the winter. So I think the EV switch will be helpful in draining the battery at the end of the day.
     
  12. maggieddd

    maggieddd Senior Member

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    doesn't the ICE extra power go nowhere anyway if you start off with almost full battery and the ICE is not finished warming up yet? Seems like it would be more beneficial to start with lower battery charge level so at least you don't waste all the extra output as it goes to the battery. That all depends on the warm up time I guess.
     
  13. EricGo

    EricGo New Member

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    If I understand your post -- yes, if you are are reaching a full battery before warmup is complete, an EV switch makes sense (I think).
     
  14. jwe8f

    jwe8f New Member

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    Two people without EV switches telling each other the best way to use it... :blink:
     
  15. maggieddd

    maggieddd Senior Member

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    :D
     
  16. TonyPSchaefer

    TonyPSchaefer Your Friendly Moderator
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  17. jimgraffam

    jimgraffam New Member

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    I've found the cruise control arm to be quite convenient since it is immediately at my fingertips and I do not have to take my hand completely off the wheel to engage it.

    I'm not sure the same applies to the OEM switch, but for the Coastal version I recommend two things: small fingers and a warm place to do the install. Beyond that it was pretty straightforward (and of course mildly stressful).

    Performance-wise, I see exactly what you are hoping to see... a quick recharge of the battery a short time into my trip following a generous use of EV. On my way home from work, I EV my way from the top of my hill, along my street, and down my driveway (around .4 mile). I can typically return to that point in EV mode if I'm careful about not asking too much up the gradual incline and then enjoy a generous coast down the hill while riding the brake slightly to recharge and to avoid hitting 34 mph. I then round the corner and go a short way until I really need to get up to speed. All-in-all, I get around 1.5 miles on EV. I'm typically back up to 6 bars within the first 5 minutes of driving before I get off Rt. 190 and onto Rt. 2.

    My way to the office off of Rt. 495 is pretty similar where I try to bleed off bars (I usually have all but 1 bar green at this point -- and have had all green twice before) while not on the highway.

    Hope this helps.
     
  18. maggieddd

    maggieddd Senior Member

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    thanks.
    One question, why would you be in EV mode when going downhill if you can be in neutral and waste nothing? Unless the hill is not steep enough?
     
  19. jimgraffam

    jimgraffam New Member

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    Two reasons: (1) Greed. :D I want to stay in EV for one more street before having to get up to speed w/ local traffic. (2) I'd rather stay in D anyways to have greater control. I don't see any reason to jump into N just to have to jump back.
     
  20. maggieddd

    maggieddd Senior Member

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    you can feather