Battery
      Notes
        Threads
          https://rennlist.com/forums/showthread.php?t=173274&highlight=optima
        Rating
          Be careful to get the correct rating.
          From memory, different 964 subtypes need different 'strengths'.
          Actually, it is not strengths but rather the capacity of the battery.
          There is no harm in having a 90Ah battery if you only
          need 70, but it canbe annoying for a Cabrio owner if he has too
          little capacity....
        Size and footing
          One important feature is that it has is the proper feet on
          it for the Porsche battery clamp. 
      Optima red top. ~$100 (12-04-2004)
        x - don't make this any more - RED75/35 model
        Fits pefectly with stock battery clamp.
        3 year free replacement and 7 yr pro rated.
        Can be found around $100 (Costco) or $120 (sears).
        Nothing has the cranking power of the optima. By far the
        best battery going. A big plus is you never need to worry
        about acid spilling and damaging the floor pan.
        I have had several optima batteries and seen them last
        upwards of 9 years, they also will recharge if you drain
        them unlike standard batteries.
      Autozone ~$60 (12-04-2004)
        Something like a 7 year warranty with first 2 years free replacement.
        One important feature is that it has is the proper feet on
        it for the Porsche battery clamp.