Folks, I think I'm needing a new battery since it's 6 years old (2004 C4S). But the car only had 17k miles... Since the car is sleeping for the winter, I didn't want to buy a new battery. I'd rather wait until it comes out of hibernation.

So I pulled the battery out and looked at all the fluid levels. Looks like it's about 50-75% full. I assume that's sulfuric acid in there.

So my question is, should I top that off? And with what? Distilled water or sulfuric acid? The goal is to prolong the battery life enough to survive the winter and into the spring.

Thanks in advance!

 

At 6 years you should probably plan on replacing the battery. Not much life left in it even with new fluids.

 

Top it off with distilled water, fully charge the battery (and use a battery maintainer over the winter) and see how it works for you.

I agree with Dharn55...at 6 years the life left may be short, but the above is likely to get you through the winter.

 

Yes, I said in the original post, I plan to buy a new battery during the Spring. I.e. - it makes no sense for me to buy a new battery only for it to sit through the winter. My question was on topping it off with distilled water or sulfuric acid.

Thanks Cab. Would you happen to know if there's a difference between topping it off with distilled water vs. sulfuric acid?

 

Unless the battery is leaking all over the place (in which case you'd have bigger problems than a battery to worry about!) it is only water that disappears over time...the acid itself does't. Adding water only replaces what disappears, and the resulting mix should be the proper strength.

Good luck.

 

So I added distilled water... I did this and it seems like it may have shorted out the entire battery. Of course, in "not easily readable print", I ended up seeing the "min/max" level line which I assume is the water line. I overfilled it. But I'm charging the battery back up now and am hoping for the best. All the excess water is coming out of the drain hose - by design. Crossing fingers at this point....

 

Ok, so the above didn't work and I sucked it up and bought a new battery...

Autozone specs out a Duralast H8-DLG. When I brought my original battery to Autozone, the Duralast H8-DLG was a bit longer than the OEM battery for my 2004 C4S. Luckily, I asked the salesperson to check with me what alternatives they had. We put my battery next to some other ones and found an EXACT size match. Here are the specs below. It cost me $145 with the $12 core charge ($157 without).

Duralast
Part Number: 94R-DLG
Weight: 47.4 lbs
Warranty: 8 YR
Application: Automobile
Cold Cranking Amps (CCA): 730
Core Charge Applicable: Yes
DIN Designation: H7
EN Designation: 77L4
Height (In): 7.5
Height (mm): 190
Length (In): 12.4375
Length (mm): 315
Width (In): 6.9375
Width (mm): 175
Weight (Lbs): 48.5
Post Location: Top Post
Reserve Capacity (Min): 140
Right Or Left Hand Positive: Right
Voltage: 12

It's a bit pricey but still better than the $250-$300 or whatever Porsche is charging nowadays for a battery that probably doesn't have the same cold cranking amps.