996 C4S

Guys

Based on the owner's manual it recommends the battery gauge to be between 12 to 16. My car is currently showing 13 and it's about 4 years old and a little over 15k miles, therefore is it time to replace the battery????

Thanks

99firehawk

the battery guage has no measuremnt of battery life. you need to perform a load test to tesst the battery.
is your voltmeter at 13 with the car running or the car off?

996 C4S

13 is with car running???

AsianImage

I read that too in the manual..but my battery volt meter reads BELOW 12...it is in the middle of 10 and 12.

Yet I have zero problems with the car....

it is a 2001...so maybe its time to change? I swear there is ZERO PROBLEMS...and I have left the car for days at a time etc. I was worried that the batt may be going bad too since it was NOT reading above 12....am I looking for trouble?

99firehawk

if your between 10-12 with the car running your going to be needing an alternator sooner then later

AsianImage

DAYAM...really? I better email the service advisor that performed the PPI and gave the car a gold star and said it was perfect in everyway.

Wellardmac

Just to give you an idea about the lack of a link of the battery gauge to battery performance.

My OEM battery died a couple of weeks ago. It was reading 14 consistently. One day I got in the car and it wouldn't crank. I recharged and all was fine for 4 days (including the reading on the battery gauge), then it died again and would not hold a charge - time for a new battery and all has been fine since then.

Batteries can die slowly, or abruptly.

RamVA

I wouldn't replace your battery until it dies. I can't think of any reason to do it pre-emptively.

iman11348

How long do these batteries last? I have an '01 C2 and it still has original battery!

Wellardmac

you're usually good for 5 years.... sometimes longer if you're lucky. I had one battery last 8 years.

99firehawk

there is no such thing as a battery guage
on your dash is a volt meter it gives an idea of th4e vehcile current power output.
with the car off key on the guage should be 11-12 volts give or take if its slightly discharged or freshly charged.
With the car running you should see 13.5-14.5 volts on a propelry opeating charging system maybe 13.0 if all loads (accessorys ac radio wipers lights defrost ect) are on.

AsianImage

hmm...ok well then my car's charging system must be off then right? Because is never goes to 12 in my ride.

I am above 10 and below 12 all the time.

99firehawk

you should get it chekced

CT03911

Good battery indications and performance. One day it was just dead and would not accept a charge. It was a three year old battery on a car that had 5k miles, ie little use. Remember, our cars are a little bit of a hassle if the battery is dead and the doors are all closed. You can get in the cabin with the key but remember the trunk and engine lid will not open with the swithches. I say replace it if it's over 4 years old. it's a battery, they don't last forever. The original post may indeed have something else going on too, just talking batteries here.

wwest

First, I would sincerely doubt that anyone at Porsche would attest to the accurracy of that voltmeter. BUt more importantly I really have no idea why it's there. IMMHO you should tape it over or learn to ignore it completely. Maybe watch to be sure the voltage doesn't drop significantly when you first switch on the street/parking/HB(***) headlamps, but otherwise....

*** HID LB current draw is too low for a good test.

Battery failures are generally the result of metalic debris flaking off the plates during use and then eventually piling up on the bottom high enough to short out a few plates. You may notice that deep cycle batteries have a greater distance between the bottom of the plates and the bottom of the battery container for this very reason.

The only reliable method I know of detecting that the battery is on the cusp of failure is to take note of the engine cranking rate.