2012 Charging issue?

[Deplorablican]

My headlights have a slight flicker to them, and when my interior lights are on ( only with car running ) they flicker as well. DIC stays between 14.6 and 15.1 V . My 2014 I previously had seemed to drop down to 12.6V after some driving. No codes are being thrown. This is my first winter with it, and it starts up just fine in the morning, even when its 2 degrees outside. Where would you start checking?

 

[Rich B.]

This seems familiar… know the AGM batteries will revert back to battery vs alternator voltage if completely charged up while driving. Flickering lights may be normal if say battery is on its way out and alternator is carrying automotive loads. DC rectification will be a positive cycle pulsed delivery. If say diode bank was gone alternator couldn’t supply the required volts to maintain battery or required volts/amperes for accessories. And cars used to all have ammeters before it was figured Volts was way cheaper to monitor. RPM may be a bit too low at idle also.

By chance is your battery one of the AGM’s? They do operate strangely.

 

[Deplorablican]

This seems familiar… know the AGM batteries will revert back to battery vs alternator voltage if completely charged up while driving. Flickering lights may be normal if say battery is on its way out and alternator is carrying automotive loads. DC rectification will be a positive cycle pulsed delivery. If say diode bank was gone alternator couldn’t supply the required volts to maintain battery or required volts/amperes for accessories. And cars used to all have ammeters before it was figured Volts was way cheaper to monitor. RPM may be a bit too low at idle also.

By chance is your battery one of the AGM’s? They do operate strangely.

Its a Lead Acid battery Group 48. The battery checks out at 12.4 V before cold start. Might need to check it after its been running and see what it checks out at. Maybe the Alternator is going bad but instead of under charging, its over charging. Not sure that would cause the headlights and interior lights to flicker though. The headlights dim bad when rolling up the window, and I can seem them dim when I turn the steering wheel, and shift out of park. So it seems something is not keeping up with the load demand.

 

[Rich B.]

Voltmeter in car should tell everything but could have lose ground or positive to battery/alternator? Should have say 15+ volts for initial startup and alternator will cut back some. Accessories will keep volts higher but have never seen cutback to 12.5 volts with flooded battery as AGM when nothing or little drawing from circuit with motor running.

GM used to have the Idiot Light in series with alternator regulation, single wire type. With short circuit, bulb would glow bright. If filament in bulb opened up, alternator would stop working with no indication. They stopped that decades back I’d of thought. Can run around quite awhile like that but battery never really charges… new alternator, nope. Light bulb burned out.