You dont remember and did not write down what wire you disconnected ??
I am hoping you disconnected it at a plug instead of cutting it , but basically its the charge wire , so just locate the Regulator/Rectifier on the subframe , and look for the connector , it will either be the Red/White wire , or the Yellow wire or the White wire or the Green wire (its a 4 wire connector) , i am not sure if that is where your battery instructions said to disconnect , but that is what the Service Manual says is the Battery Charging Wires , so that is the best place to start , once you get the 1 wire that was disconnected hooked back up the bike should charge again (i am thinking its the Red/White wire that is disconnected)
Hope that helps !