Question about the Ctek battery tender
 

I drive the Boxster about once per week, but as it gets colder, there may be times it's two-weeks between drives, so I guess I should hook up a tender to the cigarette lighter.

From what I have read, the Ctek is the one to buy, or something similar.

I found the CTEK Multi US 3300 12-Volt Smart Battery Charger on Amazon, but it calls it a charger, even though I have seen that several are using this Ctek 3300.

Is this the correct one to maintain the battery charge?
Does it also charge if I should ever have a dead battery?

Thanks,

I have a battery tender jr. You have to buy the cigarette lighter adapter separate. I plug it in during the winter or anytime the car will set more than a couple of weeks. Keeps the battery topped off. It will charge your battery to it's full limit and keep it there. Very compact. Check them out at amazon. Bought mine at Sears.

The Ctek 3300 is an excellent choice, unlike the Battery Tender and other cheaper units, every Ctek has a desulfating step in its charge profile, and all models have a specific charge program for the Optima spiral wound AGM batteries as well. Great units and worth every dime.

All maintainers are just that; they are designed to maintain a battery that is already in a generally good state of charge. They are not for charging dead batteries, they simply lack the amperage for that.

Most maintainers require that the connected battery have a certain charge already before they will even turn on.

I used the little/cheaper Ctec branded by Porsche with the lighter plug in for probably 5 years for maybe 3 months of the year or any time I'd be away for a long time. I'd pull my car out from undercover at the first few days of 40+ weather and it always was eager to start.

I bought mine directly from the company. They were very helpful and I paid about $70. Cig adapter came with it. I believe they came out with a "newer" model when I ordered mine in February '13.

If I ain't driving it, it's plugged into the battery maintainer. Easy peasy.

I bought one but didn't buy the lighter plugin. Will the wire to the battery clips close nicely under the hood if I just go direct to the battery? I assume I would use the winter setting.

You can connect it directly to the battery, but it is much easier using the cig lighter plug adaptor. What you call the "winter setting" (LED is marked with a snowflake) is for the AGM style battery (Optima and the like that require a special charge profile), what you want is the LED with the image of a car (conventional flooded cell batteries).

I went out and bought one of these today from Home Depot. It is charging as I type.

Amazon.com: Black & Decker BM3B 6V and 12V Battery Charger / Maintainer: Automotive

Thanks for all the feedback.

I ordered a Ctek from Amazon last night after reading some of the posts. Got the extra cig. adapter also.

It should be here in a few days. :cheers:

The door weatherstripping has a cut in the bottom just perfect for routing the power cable through. I just sat my maintainer on the passenger's floorboard.

I bought my CTEK 3300 from my local Porsche Stealership. Sure, it cost me twice as much and does the same thing, but mine says "Porsche" on it. (Tongue firmly in cheek.) Whenever the Box will sit for three or more days, especially in the winter, I plug her in.

Make sure your battery is as healthy as it can be. Meaning, it is fully filled with distilled (or deionized) water. Wear eye protection, and rubber gloves when checking. This, combined with a quality batter maintainer, will allow a battery to last well past 5 years.

I re-read the manual today and the paragraph for the snowflake setting says 'for a battery at temps less than 41 degrees F. It is also for a AGM battery.

Since my car will be in an unheated area, i think I will use that.