I use AGM, Advanced Glass Matt, batteries in all my vehicles. They have no corrosion, are starting batteries with deep cycle qualities. They hold a charge for a long time, can be drained and recharged with much less negative effect than normal lead acid batteries. They can be mounted at any angle or upside down. They last longer than lead acid batteries. I have refrigerators in two of my trucks and run dual batteries. For a tractor the benefit is no corrosion, longer lasting charge and longer lasting battery. They are more expensive but are widely available.