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34R Battery -- am I stuck buying another Optima Red Top?

Discussion in 'Boxers/TR/M' started by Steve Magnusson, Jan 12, 2020.

  1. Steve Magnusson

    Steve Magnusson F1 World Champ
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    Jan 11, 2001
    18,729
    Texas
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    Steve Magnusson
    My 2-year old Optima Red Top Battery is showing signs that it's on the way out. I'd like to buy a high quality lead-acid 34R that might last more than a few short years, but can't find one. All 34Rs now seem to be expensive AGM crap ;). Anybody have any recent 34R battery suggestions?
     
  2. Meister

    Meister F1 Veteran
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    Apr 27, 2001
    5,063
    Duluth, MN
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    The Meister
    I just picked up a 94 348 spider. My 1990 348 TS had the battery in the back so I did some research on the new car and things led to it requiring a 34R. Consensus was also that the cables on the 348 were long enough to accommodate a plain 34 size. While standing in front of the batter rack I happened to notice that the 36 size was the same dimensions as the 34 and they had a 36R so I bought the 36R. I have yet to install it but all I know is that the 34 and 36 were the same physical size.
     
  3. Meister

    Meister F1 Veteran
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    Apr 27, 2001
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    The Meister
    so this made me search the actual dimesnions and the 34 is 10.2x6.8x7.9 in and the 36 is 10.4x7.2x8.1 in so yes the 36 is barley physically larger.... less than 1/2" in all dimensions.
     
  4. DWR46

    DWR46 Formula 3
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    Jun 19, 2012
    1,232
    I bought my 34R from the local battery store. It is Exide brand.
     
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  5. MOSS

    MOSS Formula 3
    Rossa Subscribed Owner

    Apr 28, 2004
    1,243
    Steve have you ever tried an oddesy battery? I think its a dry cell military spec. I bought two at a huge car show 12 years ago. They claim a 5 year shelf life. Its what they put in the tanks and all military equipment. I put one in my 69 SS camaro 12 years ago and the other one I set in the shop. Shows a 1000 cca on the battery but checks 1400. Both do. 12 years later it spins the heck out of a very high compression camaro motor and I put the other one in my 33 ford blown 500 inch motor. That one is 10 years old and still awesome. 300 bucks but well worth it. I am a believer. Post are bronze.
     
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  6. MOSS

    MOSS Formula 3
    Rossa Subscribed Owner

    Apr 28, 2004
    1,243
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  7. vincenzo

    vincenzo F1 Rookie

    Nov 2, 2003
    2,665
    Two years only?

    I have much better results with a plain old lead acid - typically 5 to 7 years. Perhaps more. Even in my 26 year old F250 which sits outside all winter and often sees Overnight temps in the teens.

    Is Optima a POS?

    On all my cars, I routinely use a charger whenever it gets put away... perhaps it helps both the battery and alternator live a long and happy life:

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  8. Steve Magnusson

    Steve Magnusson F1 World Champ
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    Jan 11, 2001
    18,729
    Texas
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    Steve Magnusson
    Here are some facts/comments now that I know more about what's going on:

    My short answer would have to be "yes" as I'm not the only one here to complain about short life for the Red Top,and their warranty only being 3 years is another indication. I'm with you that high-quality lead-acid batteries that I've bought in the past typically had 84 month warranties and often lasted longer. If I could find one, I'd buy it in a heartbeat, but they just don't seem to exist. The best lead-acid 34R I can find is more of a mid-level quality (also with only a 3 year warranty) so might go that way.

    Optima indicates on their website that a fully-charged Red Top should be 12.6-12.8V, but mine only gets to about 11.9V. It still works OK at that level to start the car, and after a couple days of disuse it might be down to 11.6V and still works, but after ~5 days disuse, it's down to 11.3V and won't start. The lead-acids could easily go 2 weeks although I rarely go that long without driving (my TR has a 65mA parasitic current draw). If used regularly (like at least every other day), I doubt I'd have ever detected a problem so it probably will make the 3 years in a daily driver application.

    No. It does seem a little pricey, and their 34R size seems a little oddly shaped (being larger) at the top so might be some fiddling needed to fit it in the TR. It also being an AGM design doesn't thrill me, but their warranty/life claim is a plus over the Optima. Thanks for the suggestion -- I'll keep it on my list of "possible" when I get forced to actually buy a new battery ;)

    Thanks for the suggestion. One thing I don't like about the 36R is that it is even heavier than the 34R (which is already heavier than the stock TR battery). If I can get a 34R, I'll probably stay with that size, but don't mind having another option.
     
  9. vincenzo

    vincenzo F1 Rookie

    Nov 2, 2003
    2,665
    Just picked this up. Waiting on fresh antacid mats before installation. Still on a smart charger.

    Interstate also has an equivalent AGM that is 6lb heavier and has more CCA.

    It ‘appears’ to be a direct drop-in replacement.... but a bit taller. The vents are on either or both sides. Much better than the previous center position.

    Likely just an average lead acid battery but should be more than adequate.

    https://www.interstatebatteries.com/products/mtp-48-h6
     

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  10. bka80s

    bka80s Rookie

    Feb 4, 2020
    27
    Texas
    Full Name:
    Brian Alexander
    Any other thoughts on this topic?

    I’m going to need a battery for a 1990 Testarossa and was looking into the Interstate MTZ-34R? Anyone have experience with this battery?
     
  11. Rifledriver

    Rifledriver Two Time F1 World Champ

    Apr 29, 2004
    26,820
    Austin TX
    Full Name:
    Brian Crall
    When it comes to car batteries I never buy anything exotic. If it isn't a race application where weight is an issue I just price shop for one that fits and stay with one of the name brands. Almost all are made by 2 or 3 companies and are branded accordingly.

    Optima batteries were a really amazing product when they came out and for several years after. As soon as they were bought by Johnson Controls (a huge multinational auto industry OEM supplier) they went south fast. So yes, in my opinion they are junk.
     
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