MileHigh911

I think it is easier. The cord comes out from under the hood by the windshield. Personal preference I guess.

Mike in CA

True, and not just CTEK. One of our Rennlist members contacted Banner, the Austrian manufacturer of our OEM GT3 batteries, and they also recommended using the higher voltage "snowflake mode" to maintain their AGM battery.

GSIRM3

According to the CTEK manual, the "regular" mode is for all wet batteries, maintenance free, and gel batteries. The charging voltage is 14.4 volts.

The "snowflake" mode is recommended for charging batteries less than 41 degrees. They also state that some AGM batteries prefer this mode. Charging voltage is 14.7 volts. Hard to believe that there is much difference in 14.4 and 14.7 charging volts, but I am not an EE.

The specs on an Optima Red Top AGM battery say to charge at 13.8-15 volts. I know our Porsche batteries are not Optima, but they are AGM type. Still can't believe there will be any significant difference in the two charging modes on the CTEK 3300, 14.4 V vs. 14.7 V. I think they primarily have that mode for charging cold batteries that need the extra voltage, but do whatever makes you feel best. I think the pulse mode on the CTEK (same as the Porsche one), is the same whether in the regular mode or snowflake mode. So, after the battery is charged, there is no difference.

I am not trying to convince anyone to buy the Porsche maintainer over the CTEK, or any other brand. I decided to go with the Porsche one because they were having a 20% off sale, and the Porsche one comes with the cigarette lighter adapter. The downside of it is you can only use that method since the adapter is hardwired onto the cord, but that is the method I wanted to use. Since I didn't have to pay shipping, and I didn't have to buy the 12V socket adapter, it really didn't cost me much more than a CTEK 3300 on Amazon. Plus, in the highly unlikely event of any damage to my electrical system from using a battery maintainer, or my battery dies prematurely, I can tell Porsche that I was using their part purchased at one of their dealers.

I in fact did have one of the poorly designed plastic tabs on the adapter break off and get lodged down in the 12V socket. The connectors in the socket got damaged trying to get the tab out and the socket had to be replaced. Since it was a Porsche part that broke and caused the damage, I got a new battery maintainer, AND a new socket installed under warranty.

doubleurx

The Porsche model is actually made by CTek. It is nearly identical to the 3300 without the snowflake mode. I'd agree with you, that .3 volts is not very much. I wouldn't be surprised if that much fluctuation occurs in any charger.

Mike in CA

As doubleurx points out, the Porsche charger is made by CTek and has fewer features than the CTek 3300. Even with 20% off, I think it's still more expensive than the CTek with an optional cig socket plug. That Porsche logo is apparently very pricey. But there are intangibles and also your point about the warranty issue if something goes wrong is valid so that may be worth the price/feature difference to some.

I don't know how critical the voltage difference is, but I do know what the OEM battery manufacturer recommends, for whatever that's worth.

GSIRM3

Yeah, I know the Porsche one is made by CTEK. If you look at the bottom of it, it has a CTEK label on it. I went with the Porsche one for the reasons I mentioned. I certainly had nothing against the CTEK. If I did I would not have bought the Porsche branded CTEK unit. I was just pointing out that there does not appear to be much difference in the regular mode and the snowflake mode on the CTEK 3300. Nowhere in the manual can I find any "Caution, do not use any mode other than snowflake on a AGM battery."

Not a big deal, just pointing out a few things.

tgibrit

#2: What is the best way to connect a battery tender?[/QUOTE]

Due to the continuing freeze in PA, i decided to buy the Ctek but i have a question about how it should be connected when installing on a semi permanent basis vs using the cig socket. From the threads i have read people seem to be connecting to the battery terminals whereas the Ctek and GT3 manual both require the negative lead to be connected to a separate ground and not the negative battery terminal. Just curious why you would not connect both leads to the battery and why everyone has done just that vs the instructions in the manuals?

golfnutintib

Seems like this thread is making something pretty simple way too complicated. Cig lighter connection or direct battery connection both work, or for that matter, connecting the pigtail to the battery posts then using that to connect to the Ctek. The negative to the battery is grounded.

tgibrit

Seems like this thread is making something pretty simple way too complicated. Cig lighter connection or direct battery connection both work, or for that matter, connecting the pigtail to the battery posts then using that to connect to the Ctek. The negative to the battery is grounded.[/QUOTE]

i generally follow the instructions which tell you not to connect to the negative grounded battery terminal - it seems like most don't follow this advice so i only wanted to ask my more educated enthusiasts why that would be so?

Mike in CA

The following is what CTEK says on their web site. Basically, they stipulate connecting the negative side to ground is for regulatory and approval reasons, although they also indicate that due to the design of their charger connecting directly to the battery is perfectly safe. For me, direct connection was a matter of convenience given the length of the connecting cord and the ease of terminating the supplied eyelet at the battery terminal.

Q. Why do you have to connect negative to ground and not to the battery?
A. All CTEK chargers observe the directives that apply in the EU. All battery chargers whatever the brand must be approved in line with the same standards. Many more basic chargers can cause the battery to emit a significant amount of oxy-hydrogen gas and also generate a spark when connecting. This represents a major risk of injury and it is therefore stipulated that the first terminal should be connected away from the battery in order to reduce the risk. A CTEK charger is spark free, has a minimal amount of gassing and can therefore be connected directly to the battery. However, we do not recommend this for approval reasons.

http://smartercharger.com/faq/#application4

tgibrit

Thanks Mike, appreciate the link and info.

Riz

I just bought the Audi branded one by ctek for my R8 with snow flake. It has the +/- clips, no cigarette lighter plug. What is the snow flake for? I also have the Porsche version that goes into cigarette lighter, no clips, and no snow button.

Mike in CA

The snow flake mode charges at a slightly higher voltage. It's designed for use in cold weather and is also the preferred mode for AGM batteries, which are now standard in many cars including the 991 GT3. The older Porsche version isn't up to date with the latest tech.