hey guys in my earlier thread about batteries i was thinking this was the problem but when i went to the autozone to test my battery they told me i had 12.7 volts of juice. It seems the slow startup is on my Ist startup of the day, and 8 hours later after work. Could this be the starter? When i mean slow not to the point of continually cranking but it just seems off. Thx again in advance for any help

 

Just because there is 12.7V across the terminals doesn't mean the battery will support the load of starting. Your car is an '07. If it has the original battery, it is near the end of it's useful life. The conditions you have described lead me to believe it is at the end. Replace it.

Another thing to consider is the quiescent milliamp draw on the battery. In other words how much current the car systems draw with everything off and after sitting for a while (1 - 4 hours). Depending on accessories it should be in the 25 - 50 mA range. I purchased my car used. The previous owner had added a bunch of aftermarket electrical stuff and the battery seemed to discharge quicker than I thought it should. The quiescent mA draw was measured to be 110 mA. Sure enough after removal of the aftermarket stuff back to stock it dropped to 40 mA or so. You could also have a short circuit in one of the systems. So, even if you replace the battery if there is another underlying issue it may not solve the problem.

 

I have an o7 Cayman and I am on my 3rd battery ,They dont last in these cars

 

thx egapgt very informational had no idea about the quiessence

 

porschepet did u buy ur car new or preowned? seems like alot of batteries

 

Bought mine new .The Porsche Batteries just dont last if you ever run them down by accident . a lot of mine were due to leaving a door open ,or the key in the ignition overnight when working on my car .The Interstate batteries last longer and can take a melt down and will recharge better IMO

 

Just had my battery replaced because of the same problem. You won't believe how much better your car starts with a new battery. Kinda scared me the first start-up after the new battery was installed.