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Question re: 12-volt battery, please?

Discussion in 'Gen 2 Prius Main Forum' started by Julia2001, Aug 14, 2012.

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  1. HaroldW

    HaroldW Active Member

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    I believe so? Try it and see what happens. Be careful!!! <grin> H
     
    #181 HaroldW, Aug 22, 2012
  2. Patrick Wong

    Patrick Wong DIY Enthusiast

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    Yes, lock the doors manually and make sure you have the fob.
     
    #182 Patrick Wong, Aug 22, 2012
  3. uart

    uart Senior Member

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    Thanks for the update Julia. :)

    BTW. Are you sure that's not the other way around? Normally the voltage measured in "acc" mode should be the higher of the two.
     
    #183 uart, Aug 22, 2012
  4. SageBrush

    SageBrush Senior Member

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    I'm also surprised the battery is not showing a higher voltage.
    Question for the experts: should a 5 hour charge in READY accomplish the same charging as a 5 hour drive ?

    I had earlier calculated the battery nominal capacity at ~ 330 wh. If the battery started at 1/2 full, then it needs ~ 165 wh to fill up. At 13.8 V and 2 Amp, that implies 175/(13.8*2) ~ 6 hours of READY charging.

    I'm confused. Or my arithmetic is wrong. Or the battery has a problem.

    Addendum: A google search found one person who said the Optima has 50 Ah of capacity, thus about 600 wh. If this is correct then ~ 12 hours of charging to top-off may be required.

    Half way there
     
    #184 SageBrush, Aug 22, 2012
  5. ksstathead

    ksstathead Active Member

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    On my 2010, the in-car voltage display shows lower than when I test with my multimeter. Perhaps she and I have a weak ground at the point the car takes its measurement?
     
    #185 ksstathead, Aug 22, 2012
  6. hill

    hill High Fiber Member

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    I've noticed over the years how slow the synergy drive systems replenish. So with the more powerful Optima, that doesn't sound too horribly far off.

    SGH-I717R ? 2
     
    #186 hill, Aug 22, 2012
  7. Julia2001

    Julia2001 Member

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    Okay, so -- now that I have the OPTIMA battery, is this still a good enough charger to buy for the purpose of topping off my NEW battery, bringing it up to speed, and then charging once a month or so to keep the battery in tip-top condition? And if this is still okay even with the Optima, do I simply set it to 4A and allow it to sit overnight?

    Diehard 6A Automotive Battery Charger - Walmart.com

    Thank you very much.

    Julia
     
    #187 Julia2001, Aug 22, 2012
  8. Patrick Wong

    Patrick Wong DIY Enthusiast

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    The voltage on the 12V bus when the Prius is READY will not change whether the car is at 0 mph or 100 mph. Hence there is no need to take a drive unless you need to go somewhere.

    In another recent post I provided a link to a GS Yuasa catalog which shows the Prius battery has a capacity of 46 Ah. I assume the Optima has a similar rating.

    A 2A setting on the charger does not mean that the charger will deliver 2A constant current. It means that 2A is the most the charger will deliver and as the battery charge level increases, the charger will deliver less current.

    The Optima catalog sets the expectation that 12 hours of charging time may be required.

    One or both devices may have measurement error. If you have a quality multimeter, I would tend to trust that more than the MFD voltage readout.
    That is an OK charger and you can use the 4A setting and leave it as-is until the charger tells you that the battery is fully-charged, which hopefully will happen by the next morning.
     
    #188 Patrick Wong, Aug 22, 2012
    Julia2001 likes this.
  9. Julia2001

    Julia2001 Member

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    Thank you, Patrick.
     
    #189 Julia2001, Aug 22, 2012
  10. HaroldW

    HaroldW Active Member

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    Perfect! Go for it. The Diehard 6 amp.H
     
    #190 HaroldW, Aug 22, 2012
  11. Julia2001

    Julia2001 Member

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    Ordered it. Thank you! :)

    So EXCITED to be spending more money to bring my 200 dollar battery up to speed! :ROFLMAO:
     
    #191 Julia2001, Aug 22, 2012
  12. Patrick Wong

    Patrick Wong DIY Enthusiast

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    Last Friday in my post #73, I suggested that this would be required. Nice to see you have come to a similar conclusion.

    I recognize that many contributors on this string are Optima advocates. I've bought batteries from my local Toyota dealer on several occasions during the past few years, and in every case the newly purchased battery was fully-charged based on voltage measurement out of the box (12.9V for AGM; 12.6V for flooded lead acid.)

    Now that the MSRP of the Toyota-sourced battery has risen, Optima has become the "bargain" choice so I suppose it will be necessary to charge the newly purchased battery depending upon your local source.
     
    #192 Patrick Wong, Aug 22, 2012
  13. Julia2001

    Julia2001 Member

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    I really have to wonder why........is it because they have been sitting on a shelf for a long time?

    They should be topping off these 200 dollar batteries before they send them out.

    I have no idea if I have a bad battery, or a used battery or what...I'm trusting them.

    But frankly, at the risk of giving this entire forum a good laugh, I have actually considered RETURNING the battery and buying one elsewhere.

    Go ahead...guffaw. :D
     
    #193 Julia2001, Aug 22, 2012
  14. Patrick Wong

    Patrick Wong DIY Enthusiast

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    Doesn't your new battery have a date code sticker or some other means to show when it was manufactured? That is normal practice.
     
    #194 Patrick Wong, Aug 22, 2012
  15. Julia2001

    Julia2001 Member

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    Yes, it does. It SAYS June, 2012.

    But really...if it was actually manufactured two months ago, shouldn't it read somewhere close to 12.8 out of the box?
     
    #195 Julia2001, Aug 22, 2012
  16. Patrick Wong

    Patrick Wong DIY Enthusiast

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    Exactly. The Prius batteries sold by Toyota dealers come from Japan so they have to take an ocean cruise, then go through the US parts distribution system to get to you.

    I would therefore question whether the batteries shipped by the Optima factory are fully-charged.
     
    #196 Patrick Wong, Aug 22, 2012
  17. Julia2001

    Julia2001 Member

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    So - I did buy the charger, however, I have to ask this question...

    Would you still consider it simply a matter of charging the battery or would you suggest that I return the battery?

    I guess I'm asking if there could be something sub-standard about the battery itself?
     
    #197 Julia2001, Aug 22, 2012
  18. Patrick Wong

    Patrick Wong DIY Enthusiast

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    Since you've already installed the 12V battery and purchased the charger, I would suggest that you charge the battery first and see what happens.
     
    #198 Patrick Wong, Aug 22, 2012
  19. HaroldW

    HaroldW Active Member

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    I checked my original on my 06 today and it was at 12.58V I use a 2 amp electronic maintainer ones ever couple weeks or when the car is not used much. Its called a Eliminator . H
     
    #199 HaroldW, Aug 22, 2012
  20. dhanson865

    dhanson865 Expert and Devil's advocate

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    No, from New Optima Battery DOA (almost); And Getting Worse | Page 4 | PriusChat

    My new battery out of the box read 12.52 volts measured at the terminals (not connected to a car).

     
    #200 dhanson865, Aug 22, 2012
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