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12v battery and radiator coolant life expectancy?

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Nords, May 13, 2008.

  1. Nords

    Nords Member

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    I don't miss "winterizing" one bit, but without the threat of freezing weather we tend to ignore our car's 12v battery and radiator coolant for perhaps a bit longer than we should.

    How long can I expect our Prius' 12v battery to last? I can't see any labels on it like "60 months" (although it's hard to look under the fuse block), the info's not in the manuals, and some manufacturers have been known to skimp on their factory-original batteries.

    Although the day may be several years away, are there any Prius-specific surprises I should be aware of when changing out its 12v battery? Is there a capacitor or some other "settings backup" that'll take care of me if I change the battery quickly enough? I understand the warnings about "normalizing" the power windows and I'm pretty sure that I'll get to reprogram the radio presets, but are there any other painful lessons to be avoided?

    How frequently should we change out the coolant? There's no spec in the owner's or maintenance manuals and there's no thermodynamic reason to use "anti-freeze" here. However I'd like to keep the coolant chemistry strong enough to protect the water pump's seals from wear & corrosion.

    I'm really glad I don't have to worry about replacing starter motors ever again. The long-lived spark plugs seem to save a lot of labor, too.

    I've read through all the documentation that comes with the car and I've spent a few hours on John1701a's website. Any other surprises that you wish you'd found in the maintenance schedule?
     
  2. JimboK

    JimboK One owner, low mileage

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    I'll be satisfied if I get 4-5 years out of the battery. Some have failed sooner than that, largely in colder climates. See this thread for a good discussion on the battery, including some choices for and the logistics of replacement.

    Then for a thorough discussion on other maintenance, including coolant changes, see this.

    As for your last question, no real surprises that I couldn't get answered here. The collective experience and wisdom is incredible. The only maintenance item for which some have suggested a more aggressive schedule than what Toyota recommends is transaxle fluid changes. This has been largely out of an abundance of caution after a rash of transaxle failures in the previous generation Prius (2001-2003), though no similar trend with the current model has surfaced.
     
  3. V8Cobrakid

    V8Cobrakid Green Handyman

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    my 12v is running low. it's just over 4 years old. I've drained it way too much a couple times. If you discharge your 12v, you need to take out out and give it a full charge, or else you tend to kill it.

    the coolants are said to last 100k miles. I almost have 93k on my odometer. people who have gone over 100k say that they could last a lot longer. Brakes last over 100k miles too.
     
  4. V8Cobrakid

    V8Cobrakid Green Handyman

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    alignment... get a full alignment done on the car. i know my tire wear is extremely odd but i have yet to shim the car.
     
  5. Patrick Wong

    Patrick Wong DIY Enthusiast

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    If you don't abuse the 12V auxiliary battery by leaving the cabin lights on, and you drive the car daily for 30 min. or more so that the battery stays charged up, then it could easily last 6-7 years or more in your relatively moderate climate.

    The main surprises when replacing the battery is that the cost of the correct battery is fairly high, $160 or so; and you will note a relatively big spark when you reconnect the negative cable. When removing the battery, it may be easier for you to remove the negative cable where it connects to the body and then remove the battery with the cable attached, instead of trying to remove the negative cable terminal from the battery while it is in place.

    Regarding the engine and inverter coolant, the Toyota spec is 100K miles for the factory-fill coolant, then 50K miles for subsequent changes assuming that you continue to use the pink Toyota Super Long Life Coolant. However, I personally plan to change the coolant at 60K miles for my 2004 (now at 51K miles).

    The reason to use this antifreeze in moderate climates is for rust prevention reasons as well as to increase the heat capacity of the coolant (since it is denser than plain water). Both the engine coolant and inverter coolant drain and refill go beyond a typical DIY job. This requires access to the Toyota service documentation and the DIYer must devise a way to exercise the engine coolant heat recovery pump so that this circuit can be filled with fresh coolant. Special attention has to be paid to the inverter coolant job to ensure that all air is out of the system.

    It is true that there is no starter motor, however there are many other parts that are potential failure points which in my view more than make up for the lack of said motor. (MFD, inverter, traction battery, engine coolant heat recovery pump, inverter coolant pump, numerous ECUs, etc.) Also, it is not particularly difficult to replace a starter motor and this can be a no-brainer DIY job; while you will find few independent mechanics who can competently replace the parts mentioned above - hence you must learn how to DIY (by studying the Toyota repair manual docs) or else depend upon your local dealer's service dept.

    Regarding the iridium spark plugs, although the service spec is for 120K miles, you may find it advisable to remove them at 50K miles or earlier for inspection and to put a thin coat of antiseize lube on the threads. It is possible for water to leak from the cowl down onto the cylinder head cover and then into the spark plug tubes, which would cause misfire problems. It is not very difficult to remove the spark plugs if you first remove the relay box mounted on the cowl and have the proper length extensions for your socket wrench.
     
  6. Nords

    Nords Member

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    Thanks, I'll take another look when the battery's at its 48-month point (in a couple years). I'm more concerned about not getting surprised by leaving a light on overnight than I am about which new battery, but I hope that in a couple years it's as easy as replacing the battery on a non-hybrid car.

    Not likely to happen with a teen driver whose parents don't commute. Unless the surf is booming during a great week, this car will be subject to the most brutal short trips and occasional use. It'll only warm its oil up once or twice a week, let alone recharge the battery, so I'll expect four years of battery life. Usually by the time our cars get their six-month oil change, we've only driven 1500-2000 miles but the oil is black. It'll be interesting to see how the Prius handles that.

    Good to know. Thanks also to everyone for the links to all the battery-replacement pages, and especially to hobbit for taking all the photos and multimeter measurements. My family's having a hard time understanding why I like to know where the electrons are going...

    I'm thinking I'll stick to a dealer for this one. I have no fear of DIY but I'd rather be surfing.