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11 year old 12v battery still going strong, but should I replace?

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Jay Hansen, Jul 9, 2020.

  1. Jay Hansen

    Jay Hansen New Member

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    I obtained a tester and it is coming in at 198 CCA, so it is definitely degraded. Also, resistance is quite high at 13 ohms. I am sure the battery is near end of life, but just for kicks, I am going to turn it upside down for a while and remeasure. To understand why, google this. Voltage is holding steady over night.

    Yes, this is from the date code. It is a 2009 battery. Pic of date code attached.
     

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    #21 Jay Hansen, Jul 10, 2020
    Last edited: Jul 10, 2020
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  2. fotomoto

    fotomoto Senior Member

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    Can you post a pic? You should have enough posts now to qualify to post pictures.

    Thx.

    EDIT: OK see it now. Thx
     
    #22 fotomoto, Jul 10, 2020
    Last edited: Jul 10, 2020
  3. ChapmanF

    ChapmanF Senior Member

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    As far as I know, all of the little lithium jump packs advertise their capacity exaggerated by a factor of four. If one says it's 10,000 mAh, it's 2,500 mAh realistically as a car-battery jump source. See this post for why.

    Because they all fudge their numbers that same way (probably one manufacturer did it first, got away with it, and others said "how can we compete?"), it doesn't really interfere with you comparing them to each other. You just need to remember the factor of 4 when comparing a pocket lithium "jump pack" to something else.

    That said, even their actual non-exaggerated capacity is often enough to start surprisingly heavy loads (a family trying to start their decrepit old van in a parking lot laughed when I walked over with it, but they respected it as they drove away). Those loads are heavier than starting a Prius.

    As for the gauge of the leads ... the one I have uses AWG 10. To look at it, that's skinny compared to familiar jumper cables. But don't forget the length; these are less than a foot long. (Why make them longer? You carry the jump pack right to the jump point.)

    To make 16 foot jumper cables with the same resistance, you'd have to use 3/0.

    The better small jump packs have "smart clamps"; there is a small wart on the cables with some electronics inside. It will not allow you to reverse polarity (often a source of headaches and expense for Prius owners), and will not allow an overcurrent. The cables won't glow, they'll turn off. (That's fairly necessary for a lithium battery, as they don't respond nicely to abuse.)
     
  4. fotomoto

    fotomoto Senior Member

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    I have something similar but never intended it to "crank start" a traditional ICE. It has successfully powered up our gen 2 (at night in the rain no less) and supplied constant dc to the cmax while I carefully swapped out the original 12v so I wouldn't lose memory settings (don't try this at home kids). We have also used it during power outages to charge phones and as a seemingly never ending light source (one very bright LED). It's about 4 years old now so probably a good of time as any to swap out for a new one.
     
  5. sam spade 2

    sam spade 2 Senior Member

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    Oops. The pic that came up is of the top of your battery.
    Care to try again ?
     
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  6. Jay Hansen

    Jay Hansen New Member

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    Sam, I can't get the link to show up since I've only been a member for a day. Go to Amazon and search for
    YABER Jump Starter 800A Peak 12000mAh 12V Portable Lithium Car Battery Jump Starter Pack(up to 5.0L Gas, 4.0L Diesel Engine)
     
    #26 Jay Hansen, Jul 10, 2020
    Last edited: Jul 10, 2020
  7. edthefox5

    edthefox5 Senior Member

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    Before the 12 volt battery in the rear hatch gets to where it can be used and that’s the fuse box under the hood it has to go through the bolted on positive battery terminal connection the negative battery connection that’s bolted to the chassis which always comes loose then the main 100 amp fuse input connection that is housed in the terminal assy on the top of the battery then the output connection of the fuse then the connections at the plug in connector at that terminal that’s on the end of the 15 foot long 4 gauge cable that’s goes from the rear of the car to the front fuse box that is then bolted down in the fuse box bolt and also bolts down the vertical jump tang.
    By measuring at the front jump tang which is the only thing THE CAR SEES you are checking all 8 connections and a big cable it must go through just to get there and also checking the voltage drop if any on that main power cable that is run under neath the car.
     
  8. sam spade 2

    sam spade 2 Senior Member

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    Whatever that IS, I can't see it in the post.
    A link would be better.
    OR just type the make and model number.
     
  9. Jay Hansen

    Jay Hansen New Member

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    Since I am using a digital battery analyzer, I must check at the battery terminals. On the old battery, CCA was 188-198 over the course of multiple checks with a rated CCA of 310. Capacity was ~30Ah down from the new capacity of 45Ah, Voltage was 12.7+ volts (indicating full charge), and resistance was between 13.3 and 14 ohms. The high resistance and reduced CCA are an indication of sulfation or grid corrosion, in my case due to age of battery. Given these numbers and the diminished capacity, one study I found said batteries with similar numbers have, on average, 6-12 months of service life left...not enough for me to justify keeping it given the deal I got at NAPA. Moreover, the internal resistance causes excess battery heat upon charging and reduces charging efficiency, meaning there is a distinct possibility the weak 12v is adversely affecting my fuel mileage. I do not have a basis of comparison, though, since I bought the car in April.
     
    #29 Jay Hansen, Jul 10, 2020
    Last edited: Jul 10, 2020
  10. Jay Hansen

    Jay Hansen New Member

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    Just an FYI to anyone reading this, I bought the jump pack I referenced since it was $10 off and I paid $40..figured I'd try it and return it if it wasn't up to snuff. Yeah it is only like ~45 watt hours. BUT, it was enough to crank my subaru forester on its own easily without the lead acid battery connected at all. When I pulled it off, the charge indicator on the jump pack said it was still at 75% capacity. It is a warm day (110 degrees actually), so I don't know if it would work as well in cold weather. I am thinking it is worth keeping. Very compact and easy to store in the car when I am headed out of town into the back country.
     
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  11. dolj

    dolj Senior Member

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    Don't store it in the trunk. Behind the passenger seat or the glove box are good places for it.
     
  12. Jay Hansen

    Jay Hansen New Member

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    Yeah, wouldn't do that anyway where I live. It'd get heat damaged if left in the car all the time.
     
  13. The Electric Me

    The Electric Me Go Speed Go!

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    In regards to the battery you said this to me....

    So?
    You now have a jump pack.
    Have you replaced the Battery yet?
     
  14. Jay Hansen

    Jay Hansen New Member

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    Yes, I bought a new battery and the jump pack. I also bought a digital analyzer prior to that. While the battery held a charge, it was down to 60 percent capacity in terms of AH, down to 198 CCA, and had internal resistance approaching 14 ohms. It was only a matter of months before it stranded me and I got a deal for the NAPA battery.

    The digital analyzer and jump pack are nice to have and I can use them for other vehicles (and can use jump pack to charge things).
     
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  15. The Electric Me

    The Electric Me Go Speed Go!

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    Good.
    Those are useful tools.
    I have an ancient portable jump start pack/tire inflation unit. I lent it out a couple of times to coworkers with a dead battery. This was nice because it took my vehicle out of the loop of risk facilitating a jump start. That alone made the purchase worth it to me.
     
  16. johnHRP

    johnHRP Active Member

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    The battery gets weaker with age but it does not mean we know when it will not function anymore. The original Yuasa battery in 3rd gen last really long for regularly driven Prius, Auris, Corolla hybrid. The interior lights automatically goes to sleep even if we forgot closing the door. Deep battery drain is rare unless we don't drive for weeks.

    I know it is an old thread but we have multiple Auris owners in UK and EU who has their original battery since 2010.

    The cold crank ampere needed is only 60A in hybrid, so as long as the cells are not dead or b sorted, it still work. Just get a good decent jump starter with Li battery or super capacitors as a backup without worrying when the battery may die