Porsche Dual Mode Battery Maintainer / Charger

After sitting in my garage for over 3 weeks without any use, my Porsche 911's Interstate battery was 100% dead. When this same thing happened last year, I paid the dealer over $400 to come to my house to install a new battery. After using this unit for about 24 hours, the car started. Wow, a terrific product! Plus, it is so easy to install...plug it into the lighter socket, then into the wall outlet...and, you are ready for the magic to happen.

Love it, works exactly as it's advertised.Charges my car when it is not being driven for up to weeks.Long wire so that it extends from the back of my garage to the front.Lightweight so that it could be carried around places and traveled with if needed.Keeps my battery always charged exactly like the way you want it so that you could drive the car whenever it is necessary.Saves me a ton of hassle/headache from finding a jumper host and jumper cables.Hasn't failed me yet, would definitely recommend.

Simple and effective. My Cayman had only been driven a few times in over a month and with the cold weather my battery finally gave up. Bought this and followed the simple instructions and waited over night. The car sprang back to life the following day, I will leave this on the car whenever I go away for any length of time. Th price is a little high but you know Porsche's motto: PORSCHE, there is no discount.

The media could not be loaded.  This is the 2nd one I’ve ordered and both have had the same issue. After 1 week of continued usage the lights start blinking. It works perfectly for the 1st week, then this happens. Now I am unsure it the battery is getting a charge or not.

I store my car outside and it was very easy to connect the charger to an extension cord and keep it charged. It took about a day to charge initially as my battery was close to dying but now it only takes a couple of hours. My only concern is if the connection will ultimately be broken from rolling up my window on the cord (since my car is stored outside.) I have a convertible top so the top surface is not metal so that may protect the cord.The connection to the cigarette lighter is key! I would highly recommend that over the basic C-TEK model which connects to the battery terminals unless you add the cigarette lighter adaptor.The instruction manual is pretty poor but you don't really need it as all you do is plug it in and select the type of battery (car or other) that you are charging.At $120 this is a lot cheaper than paying for a new battery or driving my car for no purpose other than to keep the battery charged and paying $4 a gallon for gas!

I am the owner of a 2005 Boxter-S, and like most owners who live in areas with inclement weather in winter, I park my car for much of the season. Even with everything off & the doors closed & windows up, the car has a significant current draw, and will deplete the battery after a week or 2. Throw in some below zero temps, and starting the car becomes a challenge. Now there are ways to preserve the integrity of the motor & everything else: fire the car up every once in a while, and drive it long enough to bring all parts up to working temperature. This will also take care of the charge in the battery. However, the slow drainage in the meantime, followed by the heavy current demand at startup will significantly shorten the life of the battery. Enter the Dual Mode Maintainer. This handy device will keep your battery topped up during the storage phase, and is convenient enough to use even during shorter periods (vacations, etc). It has a super long cord, voiding the need for additional extension cords. I checked the voltage with an accurate digital multimeter, and it maintains the battery right between 13.2-13.4volts, which should keep the cells happy for a long time. Also the unit is current limited so if it's applied to a partially depleted battery, the charge rate is nice & slow to minimize sulfation. The only downside: if your battery is depleted to the point that it won't start the car, plan on overnight charging. Overall- an important, reasonably priced accessory.

My Porsche sat in my garage for a few months while I drove my SUV due to high water and pot holes. When I went to start it was COMPLETLY dead! My key was stuck in the ignition. I read all the ways to apply voltage to the fuse box, and on and on. So I saw this purchased and plugged it into the cigarette lighter, not believing it would work. But I went back a few days later and the car started up with out a problem. Now I leave it connected and it keeps it charged even when I don't drive the car for a few weeks.

Purchased this device to keep the battery of my Mercedes E500 fully charged. II use the car only for short trips these days; not enough to keep the battery charged.) Turns out that on this particular model of Mercedes, turning off the ignition breaks the circuit from the battery to the cigarette-lighter port, so the device cannot perform its function.I gather that all models of the Porsche maintain this circuit even when the ignition is off (though if I had a Porsche, and was considering purchasing this device for it, I would certainly confirm that this was true for my particular model before making the purchase).However, if you're considering purchasing this item for anything but a Porsche, I recommend you confirm that turning off the ignition does not break the battery-cigarette-port circuit before doing so--it may save you some grief.

Perfect option for a battery maintainer

Works great.

Easy to use, so far been great, not sure how reliable. Could just get the cheaper CTEK option but I want the Porsche badge because I'm extra.

Just a rip off. I paid 50% more for the unit for just having the name 'Porsche' on it. Go to Ctek's web site to buy the same or better for a lot less money.