Ok Guys,
I just traded in my IH 1066 this spring, the batteries in that tractor were put in new in 1995. Each vehicle I get the first thing I do is wire in a Battery Charging hookup, make it one that you do not have to open the hood to hook it up.
When you get a new battery, open her up, check the acid level, charge that battery for a week before using it, check every cell with a hydrometer, my new DX60 came with a battery and half the cells were bad on a new battery. Got a new battery from the dealer and charged it up before using it and checked it also. I also check the positive and ground connections of the vehicle. I've seen grounding points that needed to be scraped off for a good ground.
The first charge on a battery is the most important one. Every vehicle in my shop has a Battery hookup or an on board battery charger with a plug in that I can get to without opening anything. Every time that vehicle is parked we hookup a 1.5 amp charger. I like the Schumacher brand Automatic chargers.
In the fall, check that battery out, check it's fluid, top it off with distilled water only, clean those connectors and put her back on the charger. My average Diesel truck battery's last 7-9 years. I just replaced the original ATV batteries that came in our 2002's this year, I think they got weak because they were hold overs at the dealer and were not properly cared for or prepped by the dealer.
Hope this helps.