charging issues

13.6v is a whole VOLT too low for a cold battery. Go back to whatever combination gave you 14.5v

Earlier you said your battery was "good & charged at 12.05v" Nope.

12.05 is closer to dead than fully charged. 12.6+ is fully charged. I have a battery here on the bench I use for testing. It has not been charged for at least a week, and it measures 12.65v

If you have a battery charger, overnight charge the battery & check again.

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