Gravely 152Z Charging Issue

I have a Gravely 152z with a Kawasaki engine. It is a FH680V. I have a charging issue. I have 33V AC at the voltage regulator and the voltage out varies. I have replaced the regulator and it was getting 14.5 volts out but never reaching the battery. but it was not constant it was only getting good voltage out part of the time. I am not sure what else to check at this point.

I hook it to the trickle charger and mow several yards and one large yard and by the end the battery is so dead that it will not even pull the clutch in for the deck. I have had the battery checked and it shows that it was good.Pease advise.

I recently broke the main drive belt and had to replace it and in order to do that I had to disconnect and reconnect the electric mower deck clutch. I do not believe this is related at all but shortly after this is when I started having the problem.

Thanks