2006 Deere 324X. Love this tractor, but there’s a problem starting. The <1-y.o. battery shows 12.9 volts steady state, and tested good at the local parts store. Charging system works fine, cranks out 14.2V. When I go to start the engine, I just get a small click, which sounds like the backfire-afterfire solenoid, and neither the starter nor starter solenoid engage, until I connect a battery charger—and then it fires right up in a heartbeat. What can I do to correct this? Thanks!