If you "charged it" using a high amperage charger (6-10 amp rate) for a half hour, and the meter on that charger showed it was charged, it likely was not fully charged. The meters are notorious for not giving true amperage values...
When you stuck the "trickle" (Battery Tender brand?) on it, and it was only charging at 1 to 1-1/2 amps, it would require about 4-6 hours to push that last bit in.
The 14.5v you are seeing on the bike is the voltage being pushed from the generator to the battery terminals, not what is currently the voltage of the battery. Hitting the kill switch while in the voltage mode will show what the bat is at.
I ran thru this myself last weekend, and questioned it.
cleaning all the cables, and mating surfaces after that, and doing a deep cycle charge made everything correct for me.
if you put it on trickle overnight, it should be fully charged by tomorrow.