HELP: Best battery for 944??

Jon,

590 out of 600? I don't think the battery is your problem. Assuming the alternator and voltage regulator are working properly I would look at all your hi-current connections, such as: your battery terminals, and the starter connections, and the heavy cable that goes from the battery to the starter. Make sure they are all clean and low resistance.

There is no effective difference between 590 and 600 when you're talking about a battery rating. Normal production tolerances for capacity can cover 10% of nominal, and you'd never know the difference. Besides that, the rating is valid only at 70F (IIRC) and any given battery will derate over temperature at some factor unique to that particular battery. IOW, a battery rated at 500CCA might possibly have more actual CCA at 0F than another battery rated at

600CCA at 70F (when also at 0F). Depends on how the battery is made, the quality of materials, and condition of the battery.

Maybe you need an oil change to that whizzy 0W-40 Mobil 1?

Hi,

Right now I am using 15W50 Mobile 1. I fear that the car might leak terribly if I use 0W. :)

-Jon

CCA specifically refers to cold cranking amps and the spec is 0°F [-17.7°C].

Check your electrical connections to the battery and to the starter.

"Morgan Bullard" wrote in news:rFlOb.89607$xy6.162757@attbi_s02:

This seems to confirm my recent experience. I've had a lot of trouble getting my 944 to start. Worsened by the cold, but particularly after the car has not been run for a few days with the alarm enabled.

My battery was a 450A affair. I've just replaced it with a 620A battery. Seems to make all the difference.

The car has not been left unrun since, so this is not conclusive, but why my mechanic fitted a sub-rate battery, I've no idea.

Mike,

Guess what? I tested my alternator yesterday with my passport 8500 radar detector. It has a Voltmeter mode so I can monitor the voltage when I am driving. It says 12.8V at best. When I run the heat full blast, it is

12.3V!!! This is not good news. Perhaps I need a new alternator. However, the starting is only hard when the engine is stone cold. After it has been run and has the littles bit of engine heat, it will start just like my toyota! I don't think the alternator is the problem because the battery is brand new. But the alternator could become a future problem. I'll have to get that fixed.

If you're only getting 12.8V at best, it's the alternator. Actually I'd guess the regulator which will save you a few bucks.

I'd c> Mike,

Yeah... Brain fart. I was thinking about cold cranking, then went on about amp-hour and reserve rating. If cold weather operation is important to a battery buyer, he's much better off buying by CCA rating and ignoring A-H/reserve ratings.

"Jon" wrote in news:OQzOb.93960$I06.413374@attbi_s01:

Mine's a little below-par, apparently, too. Seems to be normal for an old alternator.