Mine is a 6 year old Walmart battery and I just started the tractor for the first time in a month this morning. No problems.
Not to be insulting, but I wouldn't buy a battery from JD. No telling how old it is.
But it sounds like you have troubles a new battery won't fix.
X2 on the stupid cheap WalMart battery! Got mine last summer for $24 and used it for a while. The tractor got parked and covered up in October, and that was it. Last Sunday was a fantastic day, warm and beautiful, so I was out tinkering around the shed, and pulled the cover off of the 300 just to have a look. Just for kicks, I gave the key a twist, and the **** battery was like new! It took a little while of cranking to get it to start, and the battery was on point the whole time, no problems. ****, at 24 bucks, I don't think you could beat that!:trink40: