Misplacedyankee

I always have it hooked up to tender. I noticed the tender said half battery. So I take the lift down and try and start it. Not enough juice to crank. I try twice and second time get "System Fault Visit the Workshop". I assume thats because the battery is low. The wierdest thing was my drivers side window took itself down??? I tried to use the control to bring it back up and nada? Is that a gremlin or a feature? Knowing prosche they did that for some reason.

So my question is how accurate is the tender on whether my battery is shot? The battery can't be that old and is a Porsche OEM battery that was replaced once. This is the first time the car hasn't started and it has been running fine when it did.

audipwr1

Window part way down is automatic when battery low - prevents you from breaking it when closing into door jam

100% sounds like dead battery

Misplacedyankee

Thanks for confirming. I looked thru my records it was installed in 2012 so probably just its time.

Good to know on the window thing. I figured that some porsche engineer intended for that to happen.

audipwr1

Yeah that's time for new

You motivated me to take my RS out, now up in wine country

Misplacedyankee

Oh man - jealous. Haven't had my annual dose of napa.

Igooz

What kind of battery tender do you have? I have everything on CTEK 3300's and would highly recommend them to you.

Always lock your car as it helps and quickly puts all the electronics into "hybernation" mode/lower current draw.
Also, buy an AGM battery instead of Lead Acid. It lowers the risk leakage as well as better heat and vibration performance.

I own/have owned 4 997's (2 of them I bought new), and on my 2008 GT2 I had battery leakage on the tray. It had corroded the tray, etc.

Misplacedyankee

I have two of the Porsche ones which is basically the CTEK. I use one on the GT3 and one on the GT2. Interesting tip on security. Never really thought of that.

I read that if I don't buy the porsche lead bettery the recharging system may need to be reprogrammed? I would loved to get away from the acid battery.

Igooz

I have an Interstate AGM in almost every one of my cars. Including my current '09 GT2 (same as yours) and '11GT2RS. No programming required. I run my CTEK right to the battery through that (flimsy) battery cover. I will see if I can find my posting from years ago when I swapped my '07 997TT.

(I forget now, but there are basically 2 battery manufacturers that make all the AGMs and brand them for everyone...)

Igooz

Here it is including my own post on my 997TT from years ago. GT2 = 997TT

https://rennlist.com/forums/997-turb...7-battery.html

GL

Misplacedyankee

SOLD. Interstate it is. Got a place around the corner. Thanks so much. We need to keep these 1 of 23 09 GT2s running as they should!

Reid55

The German Moll batteries suck. First replacement in my GT2 was OE from dealer. $400 and lasted 2 years. 3rd battery was a compatible Bosch (Pep Boys around the corner had it in stock). 2 years and cranking strong for well under $200.

Johnb55

After replacing the 44 lb behemoth in my '08 997 GT2 twice in four years, and feeling it's incredible weight which is mounted up high in the car, I opted for a 9 lb Lithium Iron Phosphate battery (not Lithium Ion, which can catch on fire) from Voltphreaks. That was two years ago and it has been flawless ever since. They're a little expensive, but save a lot of weight up high in the car and have been dead nuts reliable. I have since put them in another street car and two race cars. No failures. Tony at Voltphreaks is very helpful. I know this sounds like an ad but I have no affiliation, I just like the product.

http://www.voltphreaks.com/products_street.php

Misplacedyankee

$1900? Wow. After a bit of a read I will admit impressive, but wow.