Ive noticed that since its gotten colder out after I start the volt gauge stays at ~16V for a few minutes then goes back down to like 14.5V. The alternator should be good it was changed about a year back for a new one. The battery cables dont seem corroded at least what I can see of them. Wires are snug on the alternator and the battery. I checked the voltage before I started it today when it was 50*F out and it was like 12.12 which from what I can find online is only around 50% charged. I make short trips only basically, but it seems to crank over fine still. The battery is 3.5yrs now is it starting to go or do I need to invest in a decent charger for it to get it charged fully? If I need a charger whats a good amp charger and brand, any help is appreciated.

 

Battery voltage fluctuates with temps... your voltage sounds fine. Your battery IS old though.

 

I had where my voltage fluctuates a month ago also and it turned out to be a lose wire. The fuse box under the hood theres a main postive connection there, with i think it was a 10mm nut make shure its thight mines was lose.

 

Yah just checked alternator connection, battery terminals, and the bus on the drivers side. Drove it after and I think voltages are actually getting lower.