Q – My 2005 Carrera has been starting fine but last time I took it in for an oil change, the battery tested at only 12 volts static when is should have been 12.6 volts. While I thought that it was just fine, I was told that it was in a low state of charge. The shop mentioned a possible charging system or amp draw as possible causes of this condition but again, the car started fine so I did not think it was a real problem. Since I planned to visit a dealership for another matter anyway, I decided to get a second opinion. They agreed that the battery was low but then told me that it was not a Genuine Porsche and it was too small for the car. At this point, I became perturbed, as I had just bought that battery from yet another dealer the year before. So I went back to dealer A and mentioned that dealer B said that dealer A had sold me the wrong battery and that is was too small for the car. Dealer A disagreed, insisting that there was no problem with the battery and that it was the correct battery for the car. Furthermore they refused to do anything about it. I then returned to dealer B and had them install a Genuine Porsche battery. Did I get scammed? Dave
Dave, something is fishy here on a number of levels. Starting with the last issue first, Porsche does not manufacture batteries for their cars, they purchase them from a vendor who labels them with a “Genuine” label and then they are sold through the dealer network. Dealers are not obligated to sell only “Genuine” batteries. There are a number of reasons to consider alternatives. One factor is warranty coverage, another is brand recognition, and finally there is price. If there was a difference which you considered significant, you might have gone with a Genuine Porsche product. Apparently they did not give you a choice. Shame on them for that; now you are ticked off and you won’t go back.
As far as the size of the battery being a cause for low voltage, I disagree. The external size of the battery relative to capacity can fool you. The smaller battery can have the same or better ratings than the Genuine battery. The only way to know for certain is to compare the specifications, but unfortunately dealer B did not do that. They replaced your one year old battery, took it in as a “core exchange” and sold you a new battery that possibly has a shorter warranty than the one they removed. I find that annoying, especially since I like you. Something definitely smells fishy to me.
When a battery tests low on charge, the logical thing to do is slow charge it, load test it again, then call it pass or fail. Simply finding it low on charge does not constitute failure. After all, you said it: “the car was starting fine.” When I find a battery low, a series of questions follows and I may recommend a battery but only as a test part, not simply because I am in the business of selling batteries. I suspect that you have a problem with the car or the charging system, since you have now replaced two batteries within one year. If left undiagnosed, my hunch is that sooner than later, you will have a symptom that will bring you back in for a diagnosis…I hope it is not on a flat bed. MC