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Do I need a new battery?


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Quick Question:

I have a 99' C4. All is well but it seems like the battery is really getting taxed when starting the engine. I am not paranoid but I would rather save myself (worse yet, my wife) from being stuck in parking lot.

Does the battery die a slow death over a period of time or does it happen all at once? TIA

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Either. A battery can fail quickly if there is an internal disconnection or terminal fracture etc. Over time, however, the plates get sulphated - an irreversible characteristic of 'wet' lead acid batteries.

Roughly, 5 years is about the life of a battery, if yours is the original, its had a good life!

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Quick Question:

I have a 99' C4.  All is well but it seems like the battery is really getting taxed when starting the engine.  I am not paranoid but I would rather save myself (worse yet, my wife) from being stuck in parking lot.

Does the battery die a slow death over a period of time or does it happen all at once?  TIA

Also try to regularly use a battery maintainer available from your local Porsche dealership (about $75.00). It helps prolong the life of your battery.

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Thanks. The battery was replaced about 2.5 - 3 years ago. Sometimes it seems to have great power and others like it will barely get the job done. The cold starts seem strong and the starts after a short stop seem weaker.

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Thanks.  The battery was replaced about 2.5 - 3 years ago.  Sometimes it seems to have great power and others like it will barely get the job done. The cold starts seem strong and the starts after a short stop seem weaker.

Skymast,

My 99 C2 Cab does exactly the same and the difference between cold starts and warmed up starts is considerable. You'd think it would be the other way round. Who made the original batteries so i can check if mine is original?

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Because the timing of engines is set before top-dead-center, it's harder for an electric starter to turn the engine when it's hot. Cold engines don't fire right away, but just-run warm engines fire on the first spark. The end result is the starter is fighting to push the cylinder to the top of the stroke while the explosion is pushing it the other way (backwards).

Combine that with the fact that all the electrical components are less efficient when they are hot and you can see how a weak battery could put the whole system out of balance.

So much so, that on my old 75 Mercury with a big block, I ended designing and installing an automatic timing delay relay to the ignition coil so that the starter could build momentum of the engine before power was fed to the coil to spark the cylinders.

Edited by PorschePRH
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  • 1 month later...
  • 3 weeks later...

after leaving the car in the garage for 4 weeks, the new battery was no longer a question mark but a requirement. duralast 48 DL did the trick for $65. Without shame, I installed it in the parking lot of AutoZone next to a guy working on his Camero.

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Out of curiosity regarding batteries. I notice when I first start the car, my V one display is normal then dims, then normal then dims. I seen this problem for some time first noting the temp display for the AC doing the dimming thing. I start driving and it's fine, probably supplemented by the alternator. Does this mean I need a new battery? I don't know how old it is. Thanks.

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SPR, mine does the same ( C2 1999) and I have a new battery installed. That does not seem to be the issue. Car electrics is somewhat of an antiquated science for sure. In addition to this feature ( dimming immediately after start-up) I also notice that the charge , based on the position of the needle, seems to go down by at least 1 Volt when I have the airconditioner on. It goes down to about 12.5 volts where as I would assume 13.5 - 13.8 Volt is what it should be. It is almost as if the alternator can not supply sufficient voltage OR because the voltage regulator was designed and produced in 1942 by Mr Lucas himself. I am of course assuming that the voltage level shown on the gauge is measuring the voltage that is charging the battery. I would take that this is a correct assumption. However, I seem to get surprised over and over again. Maybe it showing the voltage to some other electric device hidden in the bowls of the car... who knows. Yes, who knows ???

HarryR

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I would think too that the voltage regulator maybe the problem but unless I am mistaken new cars don't have those anymore. I will have to check and see the ac deal and other things. I always not that when I initially flick the litronics on the amp meter goes down about 1/4" and comes up. I also have a pretty hefty JL amp in the boot that I am sure likes to eat juice based off how warm that thing gets.

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