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after market 12v battery?

Discussion in 'Gen 2 Prius Technical Discussion' started by hschessler, Dec 28, 2008.

  1. hschessler

    hschessler New Member

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    I didn't use my 07 prius over the holiday for 3 days.
    I planned ahead and deactivated the SMART function to save some juice.

    But this morning the 12v battery had discharged.

    I am wondering whether I should purchase a larger amp battery than toyota puts into this car so that I don't need to boost it after I don't drive the car.
    I have always felt that Toyota's battery is undersized. My dealer tells me that the car is designed to be used every day to keep the 12v charged.

    If a higher cap. battery is not advisable I'll have to get a trickle charger. I really really don't like having to connecting a charger and waiting a 1/2 hour to start the bloody car.
     
    #1 hschessler, Dec 28, 2008
  2. efusco

    efusco Moderator Emeritus
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    Your battery shouldn't die that quickly. I've left mine for as long as 12 days unused without ever draining the battery.

    You can retrofit an Optima battery ( a search here will find info), but the OEM battery has plenty of capacity and the car does NOT need to be driven daily. There's either some abnormal parasitic drain on your current 12v or the battery itself is bad (was it every totally depleted before?).

    My original OEM battery lasted 4 1/2 years before I had to replace it, and I probably could have gone another few months.
     
    #2 efusco, Dec 28, 2008
  3. qbee42

    qbee42 My other car is a boat

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    Three days is way too short to kill your battery, unless it was previously damaged or you left something on in the car.

    Tom
     
    #3 qbee42, Dec 28, 2008
  4. donee

    donee New Member

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    #4 donee, Dec 28, 2008
  5. Cootunit

    Cootunit New Member

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    Hi H,

    I basically agree w/the other posts, i.e. something must be amiss in terms of draining the battery (like the JBL sound system) but most likely I think your battery must have been crap. Being an '07, shouldn't it still be under warranty? Worth a look. I love the fact that you turned off the smart key as you were thinking ahead and clearly have a clue. Our '08 just sat for a week in some really cold weather (which has since turned tropical) and did fine.

    I think the OEM 12V is small, but should be able to handle several years of service. By the way, I see some recommend an Optima battery and I must share my experience. I put one in my '88 4Runner and it died frequently. Absolute shite. I'm just sayin'

    Best of luck-

    Coot
     
    #5 Cootunit, Dec 28, 2008
  6. xsmatt81

    xsmatt81 non-AARP Member

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    thats strange about your optima dying quickly like that, you must have bought a dud battery

    my mothers mazda has had the same optmia battery I put in back in 2002 and it's still going strong

    I have looked over that guide for installing an optmia but think I will wait until the stock unit is toast.
     
    #6 xsmatt81, Dec 29, 2008
  7. jdenenberg

    jdenenberg EE Professor

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    Coot,

    There was a period of poor quality in some Optima models causing Optima to discontinue those models for a while. I believe that the problems have been fixed now and they seem to be delivering good product again.

    The Elearnaid kit referenced earlier is a good choice for a Prius replacement battery as they supply the required adapters for the Japanese electrical connections and vent tubing to fit this battery into a Prius.

    My 2004 Prius is still running on its original 12v battery at 138,000 miles and 4.5 years with no problems. The OP must have a weak battery. As was stated before, draining the 12v battery weakens it. Some Prii have even been delivered with a weakened battery when new so check the waranty.

    JeffD
     
    #7 jdenenberg, Dec 29, 2008
  8. Hytec

    Hytec New Member

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    The battery on my 2005 very nearly died in about four hours because I didn't realize the hatch lid was not fully closed, and the hatch light had stayed on. The hatch lid had clicked on the safety catch, but not the final lock which would have turned off the light. I didn't see the light because the car was parked in bright sunlight. My point is that you shouldn't automatically blame the battery until you have ruled out other less expensive causes.
     
    #8 Hytec, Dec 29, 2008
  9. donee

    donee New Member

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    Hi Matt,

    The OP is having trouble with the stock battery (probably a Yuasa AGM style battery) , which is not an Optima battery.
     
    #9 donee, Dec 29, 2008
  10. donee

    donee New Member

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    Hi hs...,

    I notice your car is a Package #1 - is that right? Do the lower packages come with Smart-Key now ? If your car does not have the JBL stereo, that would be more evidence of a either a bad battery, or a parasitic drain while the car is off.
     
    #10 donee, Dec 29, 2008
  11. hill

    hill High Fiber Member

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    He said he put in in a rig that was appx 2 decades old, so maybe he's talking about an optima from long ago (exasperated over not enough data :p) and I mention that because back in the day, the optimas DID have issues. Within the last couple years though, they've been solid as a brick house. Besides, there's a HUGE application difference between a truck that needs cranking amps vs the prius, which meerly needs 12v to boot up ECU's. The Prius' small boot up power needs is the rational that Toyota relied on when they used such a small battery. Ergo, leave it on, and it's at your own peril. :eek:
     
    #11 hill, Dec 29, 2008
  12. hschessler

    hschessler New Member

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    I want to add to my original post some of the history of my battery "failures".

    This car (now 2 years old) has been to the dealer 5 times.

    The first time when it was 4 months old.
    I was ignorant (about Prius battery) back then so when it didn't start 1 day I felt that the problem had something to do with it's electronics. I reason that It had to be towed.
    The dealer replaced the battery and they had nothing to tell me to indicate where the failure occurred -- was it only a bad battery?

    A short while later it had to be towed again & replaced battery again. By this time I was getting worked up -- I was more insistent that I get an answer! Was I part of the problem? Had I been a leaving a switch on/not closing door all the way? The answer this time was: "when you turn off the ignition you are leaving car in accessory mode". So, i became very alert to turning it off exactly as the Prius manual dictated.

    Once again, no start. By this time I learned to avoisd a tow by charging the battery with my tractor charger -- then drove immediately to the dealer. You can probably see the pattern: replace battery, offer an accuse. I demanded to speak with the service manager. He told me to drive the car EVERY DAY (or at least run it for an hour) because the car was designed to be used! BUT THIS TIME I was ready for him! With the help of THIS FORUM I had learned that my problem was most likely due to the SMART entry system & its power drain on the battery and that I could disable it while the car sat (I don't read user manuals unless I have to). I printed off your answers and handed all the advice you gave me -- I think I threw it at him!! I kept asking him why he didn't tell me about SMART. He didn't answer -- all the inconvenience and waste of money that this guy was responsible for -- don't know whether he is just incompetent or stupid.

    Well, the use of the disable SMART has worked for a year when I don't use the car over a weekend, but this time the problem is back for a 3 day holiday. So I think I use a "Battery Tender" when the car sits for a few days. To really fix the problem will cause me too much grief.

    Many thanks to PRIUSCHAT
     
    #12 hschessler, Dec 30, 2008
  13. Patrick Wong

    Patrick Wong DIY Enthusiast

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    This is a reasonable solution. I'm wondering what your odometer reading is, and how many miles you currently drive weekly.
     
    #13 Patrick Wong, Dec 31, 2008
  14. richard schumacher

    richard schumacher shortbus driver

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    Always lock the car when you leave it. Most times, if something is amiss that could drain the battery it will beep at you.
     
    #14 richard schumacher, Dec 31, 2008
  15. bif

    bif Gas Saver

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    Maybe you have a faulty rear hatch light switch? You can shut the switch off so the rear hatch light never comes on. I do that and I left my Package 6 with JBL system parked for a week with no problems.
     
    #15 bif, Dec 31, 2008
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