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MPG Boost After 12V Battery Replacement? I Think So!

Discussion in 'Gen 2 Prius Fuel Economy' started by Prius_Cub, Apr 6, 2013.

  1. Prius_Cub

    Prius_Cub Member

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    After getting my old battery replaced, here is my average so far, granted, its only been 40 miles since the battery has been replaced as of earlier today, but...57.5 MPG after 43 miles. Can't wait to see how the next full tank is going to turn out. I love my Prius more and more every day!
     

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    #1 Prius_Cub, Apr 6, 2013
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  2. bisco

    bisco cookie crumbler

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    cool! what was it before?
     
    #2 bisco, Apr 6, 2013
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  3. Prius_Cub

    Prius_Cub Member

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    I generally average around 47-49 MPG driving to/from work or long distance trips on the highway.
     
    #3 Prius_Cub, Apr 6, 2013
  4. bisco

    bisco cookie crumbler

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    beautiful, that's a big increase! what kind of battery did you get?
     
    #4 bisco, Apr 6, 2013
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  5. Prius_Cub

    Prius_Cub Member

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    Stock from Toyota, I just bought my Prius around the middle of February and I still had a warranty on the battery. Free, but when this one goes, I'll be getting something different. :)
     
    #5 Prius_Cub, Apr 6, 2013
  6. SteveLee

    SteveLee Active Member

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    Can't beat free! Way to go.
     
    #6 SteveLee, Apr 6, 2013
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  7. Prius_Cub

    Prius_Cub Member

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    Thanks :) I'm excited to see how big of an improvement I get after the replacement. :D
     
    #7 Prius_Cub, Apr 6, 2013
  8. fentos

    fentos Junior Member

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    Very nice. Did you have warning signs that your battery was going bad or did you just check the voltage? I'm in the process of trying to track down a recent drop in mpg's and am thinking the battery might be the culprit. Did you install yourself or let the dealer do it?

    Also, see you are in Radford. I live over in C'burg! Nice to see another local on the forum!
     
    #8 fentos, Apr 21, 2013
  9. Prius_Cub

    Prius_Cub Member

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    fentos, I had indicators for the brakes, vsc and such so I figured I'd test the voltage, but those have been occuring on/off and I strongly suspect it happens if I leave my bluetooth OBD adapter plugged in while shutting down for a few minutes and powering back on but my voltage was fairly low and showed it was always trying to charge the original battery while running. Got the dealership to replace it in warranty as I had just got it from them just shy of 60 days prior to when I found out about the health of the battery.

    Well howdy neighbor! I'm surprised their aren't many more NRV locals than the very few I've seen on here so far.
     
    #9 Prius_Cub, Apr 21, 2013
  10. nh7o

    nh7o Off grid since 1980

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    The 12V battery problem reports here are very numerous. I just found that my trickle charger had stopped putting out, and that caused my battery to go way down. (My car is parked for long periods.) I was wondering what was going on, as the MPG had taken a hit. The ICE ran more than usual. After I found the problem, and charged the battery completely, all was back to normal. The GenII hybrid control ECU really puts a high priority in getting the 12V battery charged, but it can take a long time to do so if it is flat. So the result is that the car can be surprisingly crippled by that.
     
    #10 nh7o, Apr 23, 2013
  11. roflwaffle

    roflwaffle Member

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    I was messing around with the torque app and if the 12V is low, the engine will run for a long time at surprisingly high load (~15%) instead of consistently shutting off like it would w/o a bad battery.
     
    #11 roflwaffle, May 19, 2013
  12. Britprius

    Britprius Senior Member

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    The charging system on the Prius can and does put in excess of a 700 watt load on the HV battery if the 12 volt battery is partly discharged.

    John (Britprius)
     
    #12 Britprius, May 19, 2013
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