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Optima battery bad "again"

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by PriusGuy32, Jan 2, 2014.

  1. dorunron

    dorunron Senior Member

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    msmary,

    From what you described, I have a feeling in the end you will need a new 12 volt battery. Take the time to investigate all of the batteries that are available. I myself recommend the battery that Toyota sells.

    Best of luck to you and "Welcome to Prius Chat"!
     
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  2. msmary

    msmary New Member

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    Thanks. I've been reading about what y'all have been saying about the optima and the toyota batteries for a few hours. Sounds like the more recent posts are more negative about the optima and since both are expensive , I'll probably get the toyota since the dealer is right across the street. Still deciding about whether to attempt it myself or not. Found a battery tender in the garage so hooked it up. I think its better than the old charger I was using.
     
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  3. Patrick Wong

    Patrick Wong DIY Enthusiast

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    Typically, a battery tender will only produce ~1A of charging current. So, your old charger set to 10A would be much better.

    I assume that since you don't feel comfortable leaving the Prius READY overnight, that you also would not be comfortable leaving the hood or hatch open for charging purposes overnight as well. Therefore you probably want a fast charging solution, which the charger should provide.
     
  4. OptimaJim

    OptimaJim Member

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    Patrick, I don't know how post #49 is inconsistent with what you posted. I posted “about 13.0-13.2 volts” and you think it should be “at least 12.9V.” If I posted “exactly 13.0-13.2 volts” then we'd have a difference of a tenth of a volt. I didn't post that and so we essentially posted the same thing. There can be some variance from one battery to the next and as Gary in NY indicated, there can certainly be variability in the accuracy of measuring devices. While some battery warranties have very specific voltage requirements for their batteries, we're not going to void someone's warranty, because their charging system falls outside of a voltage range by a tenth of a volt.

    However, as a battery ages, performance will begin to decline, so it may not be unusual for an older battery (or even a newer battery that has seen significant use) to have a resting voltage of about 12.5 volts. It may still function fine for several more months or even years in a given application before needing replacement. It's when a battery is fully-charged and drops a full volt or more in a matter of hours when disconnected from any draws, that we're dealing with a battery that has serious performance issues.

    Tony D, new batteries generally don't need to be charged and checked. However, if someone is having an issue that may be battery-related, disconnecting the battery, charging it and checking it is a quick and easy way to either pinpoint the issue or eliminate the battery as the culprit. In many cases when folks are having issues with a new battery draining down, it is often (but not always) traced back to a draw in the vehicle that is discharging the battery and ends up doing the same thing to subsequent replacements, regardless of brand or manufacturer. That's why it is suggested to disconnect the battery from the vehicle when checking it- it eliminates the variable of anything external discharging the battery.

    Even a vehicle that has what PriusGuy32 cited as a “normal” 20-milliamp draw, can eventually discharge a battery. Our DS46B24R battery for the Prius is a 38 amp/hour battery. The math indicates a 20-milliamp draw will discharge a battery .48 amps per day (.020 x 24 hours). That means a 38 amp-hour battery will be completely discharged in about 79 days by a 20-milliamp draw, if the battery is not charged or maintained in some way. Moderate temperatures can lengthen this timeframe, while extreme temperatures can shorten it. This also assumes the battery is fully-charged when a vehicle is parked, which is often not the case. Even if a vehicle is driven occasionally, if the vehicle's charging system doesn't have enough time to replace the energy that was used during storage and starting, the battery will slowly become discharged over time and once a battery is discharged below 12.4 volts, sulfation begins to form, which diminishes both capacity and lifespan. That makes a quality battery maintenance device an excellent investment for any vehicle that doesn't see regular use.

    JC91006 is correct about Optima batteries not using recycled lead or polypropylene, although many OEM batteries do.

    The scenario msmary describes is what most folks do when their battery becomes discharged- they get a jump and hope the vehicle's charging system will recover it. As Patrick indicated, that usually doesn't happen and those folks often end up in a cycle of dead batteries and jump-starts, until either the battery or charging system eventually needs to be replaced. Anytime a battery is deeply-discharged to the point that it needs a jump, it should be fully-charged with a battery charger as soon as possible.

    Most chargers will also taper both amperage and voltage throughout the charging process, so even if someone charges a discharged 35 amp-hour battery at 10 amps for 3.5 hours, it will likely take an additional hour or so to get the battery fully-charged.

    Jim McIlvaine
    eCare Manager, OPTIMA Batteries

    OPTIMA® Batteries is optimabatteries on Pinterest
     
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  5. Patrick Wong

    Patrick Wong DIY Enthusiast

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    Hi Jim,

    My concern was with the first sentence of your prior post that I quoted: "If your current battery discharges from 13.0 to down below 12.0 while disconnected from your car, it should be replaced under warranty."

    After surface charge has dissipated, to see a further drop of 1V, or even 0.5V, after only one or two days has elapsed is unacceptable. I think that the voltage drop of a good battery should be no faster than 0.1V per week, when the 12V battery is sitting there on the garage floor with no load attached.

    I have an extra GS Yuasa 12V battery manufactured in 2009, sitting in my garage, which exhibits a very slow voltage drop as described above.

    However, I appreciate you being clear about the Optima warranty policy as that will help prospective customers decide which 12V battery brand to purchase.
     
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  6. OptimaJim

    OptimaJim Member

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    Patrick, I don't disagree that a battery that drops even .5 volts over a few days from it's full state of charge when disconnected from any load probably needs to be replaced. The issue is what the full state of charge should be for a given battery and as I previously-posted, that can vary, based on the type and age of a battery. I don't want people to think every battery should measure 12.9 volts when fully-charged or any other specific voltage level, because that's simply not correct. Suface charges can further confuse the issue for folks who aren't familiar with where they should expect their battery voltage to be.

    You may not like a battery that rests at 12.5 volts, but if you take it in for warranty service (whether it's our battery or any other brand) and it passes a load test, you may not get a warranty replacement simply based on the voltage level. I get e-mails from folks who charge their batteries with battery chargers and can't get them charged above 12.5 with their charger. They may get to a higher voltage level with a different charger and they probably won't have an issue either way, as long as they are putting their battery on a charger, but for some reason 12.5 volts makes them nervous and it shouldn't necessarily.

    As for the warranty policy, I always encourage folks to read the warranty policy of any battery they are considering, before making a purchase. I read a post from someone the other day who seemed pretty upset by the terms of their pro-rated warranty (we no longer offer pro-ration on our warranties), which are fairly-standard across the industry. I think what he failed to realize is that the pro-ration clock starts the day a battery is purchased, not the day his free replacement warranty expired. When it came time to get a pro-rated replacement, the amount he would have to pay was far more than he anticipated.

    Jim McIlvaine
    eCare Manager, OPTIMA Batteries

    OPTIMA® Batteries on Pinterest
     
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