Replace or Recharge Battery

[Norminhouston]

The Moll battery on my '03 BoxsterS lasted approximately 6 years. I think that is pretty darn good. As mentioned, it is important to check the fluid level regularly and top off with distilled water. The original equipment battery is certainly overpriced. I went with one purchased from AutoZone when the orig bellied up.

[Lil bastard]

@mikefocke... I agree with your testing but your values are a bit off. A healthy battery will produce about 2.2VDC from each of the six cells which are wired in series, so the battery total should produce closer to 13.2VDC. If the battery is less than that, it is either not fully charged, low on electrolyte or has broken or sulphated plates, all of which can happen to a battery over time. So, a range of 11.9 - 13.2 is probably in order.

The same goes for the alternator, a range instead of an absolute value. Bosche rates the alternator with an output of 13.5VDC-14.5VDC. Anything in that range is OK.