Small Engines (Lawn Mowers, etc.): lawn mower battery, john deere lawn tractor, john deere lawn

Question
I have a John Deere lawn tractor and was mowing the other day and ran out of gas. Because the mower shut-off, I forgot to turn the switch off and the battery evidently went dead. I charged it overnight and the mower still would not start (wouldn't even click). I then jump started the mower with my truck and it started up. I mowed for about 1.5 hours and shut it off, figuring that would charge the battery. Still would not start or even make any clicking sounds. The battery is only about 3 months old. Could the battery be bad? Shouldn't the mower charge it up while running? The battery charger may also be bad, as it is old.

Answer
Yes, it's possible the battery is defective. No the engine will not put a full charge in the battery while running, although it should put some charge in it. The engine has an alternator which is designed to maintain voltage in the battery, not charge up a dead one. If you don't have a good tester, I suggest taking it back where you purchased it and let them tell you if it's junk or not.