I know that I need a battery charger/maintainer for my 2014 Boxster, which will be stored in my garage for about 5 or 6 months this winter. The Porsche branded one seemed a little pricey so I checked out the CTEK website and found several models at about half the price. So I sent a message to CTEK asking what model is best for my specific car. The email that I received from them said: "We recommend the Porsche branded charger which is available through your local Porsche dealership." I was surprised that this was the response since they sell the device themselves. Is there any difference between CTEK products and the one Porsche sells that makes it worth spending almost twice as much on what should be a simple device? Or is it that CTEK supplies Porsche with the Porsche branded device also and they get a bigger markup from that product? Thanks for all advice.