Travis

The $20 Black and Decker trickle charger from Home Depot may be a good alternative if you can't find the CTek or Battery Tender locally.

I've been using the B&D for the last few months on the cars including the Cayenne as well as the 993. Even has three ways to connect to the car including the cigarette plug. It replaced a Battery Tender that quit on me and so far has done exactly what it is supposed to.

dugahole55

thumbs-up for C-Tek, smart charger!

ciscorp

Recently I've been researching and shopping for a battery maintainer/charger for my Cayenne S. There are a few features you may want to look for in a charger. Cayenne batteries have a high reserve amps hour time such as 160 min. or 180 min. Be certain the charger is rated and able to charge batteries with these reserve times. Some are rated at 250 amps which is sufficient. Also most chargers just charge the battery but other battery maintainers charge in stages and will condition the battery by removing the sulfates. An intelligent variable amp & pulse battery charger offering 3-5 stage charging claims to make batteries last up to 4 times longer and cost about the same. Many don't offer a cigarette lighter plug but you could always wire one in.

I have an on-board ProMariner Sport 20 battery charger on my boat that automatically charges and maintains two battery banks and conditions the batteries once a month. I never have any problems. I may buy the smaller
ProMariner Sport 6 for $75 that is made to charge one battery and either wire in a lighter plug or just mount it in the vehicle and plug in.

Corso

I have 4 of these guys, bought my first one in 2004, and they have all worked perfect. I would think it will be fine for the Cayenne as well...?

gadgetrex

I purchased the Noco battery tender (NOCO Genius G3500 6V/12V 3.5A UltraSafe Smart Battery Charger) from Amazon, along with the cigarette/12v lighter adaptor and 10 foot extension cord, and they work great. I screwed the charger to my workbench (it has holes for that; I hang the associated cords from a couple of hooks I also installed), and simply unfurl the cord and plug the device into the cigarette (12 volt) charger when my Cayenne (2012 CTT) is going to be sitting for more than a day or so. Convenient and total cost less than $85.

hahnmgh63

Keep in mind that in general a Battery Maintainer is NOT a charger and not expected, nor capable of recharging a dead or weak battery. 1/2 to 3/4 amp charge rate is fine. And as mentioned, a good smart battery maintainer will stop charging when your battery is fully charged, a cheap one might keep trickle charging your fully charged battery and it will shorten your battery life.