Thought I'd ask here in case someone who knows what they're talking about sees it.

Basically I have a month old Deka EXT12 battery rated at 180cca and ran into some problems today while it started to rain and get cold. Prior to today I have never run into this problem the almost 3 years I've had the car.

When the car is idling or at <1000rpm, if I turn things on that put a load on the electricity (heater, headlights, fog lights, radio etc), the voltage drops from 13-14v to 10-12v until the new load is turned off. All the lights in the car including gauges will flicker and dim at this point. Example: if I hold down the button to close the window, the voltage goes from 14v to 11v and stays there till I let go while all my gauges and headlights are flickering and dimming. Turning my heater on while my headlights are on killed the engine a couple times while I was driving tonight.

When I'm running the car at >1000rpm and I turn something like the heater on, there is barely any fluctuation in voltage on my Scangauge. It is the only way I can turn operate electronics right now while it is raining and cold..... drop down a gear and turn things on temporarily while I'm driving around at 3k+ rpm.

Anyone know what the issue is here? The battery with low cca or is there something up with my alternator?

 

The first thing to check is the battery terminals- are they clean and well-attached? Sometimes the terminals might be a bit smaller and you don't get a good contact even if you tighten the bolts as far as they'll go. Or they get oxidation on them (that bluish white powder).