Engine Can' get engine to turn over. No sound when I turn key.

Well here is my story. I have a Craftsman 46 inch rider with an Intek V-Twin OHV Briggs & Statton engine. I know that I have a charging system problem. If I charged the battery to full charge 13+ volts it would start normaly until the battery ran down. So in the interim I bought a Diehard 750 Portable Battery Pack to get it running if the battery ran down and I could not start it.



I would set on the tractor and set the pack on the cowl and connect the 750 and start it. Yesterday I made a big mistake and connected the Battery Pack backwards. Turned the key and it made a whiring sound. Now with a fully charged battery and/or the Portable Battery Pack nothing happens when I turn the key.



What did I mess up? Any suggestions to correct the problem?





Thanks in advance.