Battery gauge cluster reading vs health?
 

I have a few month old Duracell AGM battery. I notice on these colder mornings 0-15, the gauge reads over 14v after sitting all night and before starting. Is this normal for batteries, I've seen this with other non AGM batteries and I've never know why the volt reading increases...

is this normal, is the charging system/ battery likely in Good health?

also my passenger low beam headlight went out recently, Silverstars on a harness. They aren't 1yr so I figured ide ask if there's anything worth looking into being on topic of the charging system and the high voltage reading.

thank you kindly for any knowledge, happy New Year!

Using a digital or analog meter of quality, measure the battery voltages, both while the engine is running, and before starting in the morning.

What are the measurements?

I'd guess the harness has both left and right lights linked, if so then the supply won't be an issue as one side works. I would check the harness connector at the bulb to make sure it isn't damaged but while there, double check it does have the correct voltage there. If voltage is found then the likely culprit is the bulb.

It's definitely worth checking out the voltages with a multimeter though to make sure it is charging correctly, also check that the voltages read match what the gauge shows. You could find that the gauge is reading incorrectly.