Looks like CTEK Multi US 3300 ($69.99 via their site) is the same as Porsche's Dual Mode Charger (PN 95504490054) @ $114.95 at Suncoast.

The older battery maintainer (PN 98061198100) is $54.99 at Suncoast. Does this older one detect battery is charged and cut itself off?

 

I just got a CTEK US 3300 from these guys, price seemed very good and they had the lighter plug.
http://www.racerpartswholesale.com/c...ttery_Chargers

 

Has anyone tried putting an Optima RedTop battery in their Porsche? I did this for my other car and it can go at least 3 weeks without charging as it's a Spiracell battery. They sell it at Costco and it has a 3 year free replacement policy I believe.

 

I had no problems starting my car 1st time after the car was sitting in a garage for 3 weeks recently. I assume the result depends on both the age of the battery and the amount generally driven each day/week. IMO it would be a public relations nightmare for Porsche if batteries were dying after even 4 or more weeks of the car not being driven - assuming a full charge prior to that. If someone drives their car only occasionally or on weekends - of course that is different.

 

My understanding is that car batteries lose about 1%/day of their existing charge at approx. 70 deg. F. This does not take into account any draw from systems that may be working in the background. So, if a car with a good battery is sitting for one month at mild temps. I would imagine there should be no problem starting..... assuming no significant draw from on board systems. The charge would be weaker if at low temps. of course ( < 50F)

 

A very interesting point. Apart from starting issues though, at what point does the battery actually become damaged, i.e when does sulfation begin??

 

OK - I'm a little confused. How long "should" a Porsche battery last if you only drive short distances (not a daily driver) and you DON'T use a battery maintainer VS how long if you do use the maintainer. It appears that you could just buy a new battery after a few years and save yourself the hassle of plugging this thing in weekly.

 

I don't think that is so much the point. There is a lot of electronics in these cars and having a weak battery that is never getting a chance to fully charge is more the issue. That and having to call 1800PORSCHE to come get you once it does get too low.

And think of it - it is good practice for preparing for the day of the electric car - I'll already be used to plugging mine in.

 

So after 5.5 years and only 21K miles, I thought I should post back on this. I use the CTEK always since this old post. My drives are short - 5 to 10 miles most often and sometimes I don't drive for a few days.

I still have the original battery.

I hope this helps those considering this fairly inexpensive device. It seems to have helped keep my battery in good shape. I hope I haven't jinxed myself now.

 

The CTek is great. As others said just like the one Porsche sells but cheaper cause it's missing a badge and Porsche tax. On Amazon for $52 if anyone is interested - http://amzn.to/1vPChRy

 

Have been using these optimizers since my buying my 993 in 1995 and never had a battery go dead on me. A great insurance policy.


The first generation of Porsche Optimizers





the latest version