Batteries are often one of the most misunderstood parts of a vehicle, and this is especially true when it comes to charging them. There are a few different ways to charge a 6 volt tractor battery, and the best method will vary depending on the type of battery you have. The three most common types of batteries are lead-acid, sealed lead-acid, and gel cell batteries.
Lead-acid batteries are the most common type used in vehicles, and they can be charged with either a standard alternator or with a specialized charger designed for lead-acid batteries. Sealed lead-acid batteries are similar to lead-acid batteries, but they don't require as much maintenance and can be charged with a standard charger. Gel cell batteries are the newest type of battery technology, and they can be charged with either a standard charger or a specialized gel cell charger.
The best way to charge any battery is to use a trickle charger that will slowly charge the battery over time without damaging it. If you don't have access to a trickle charger, you can use a standard alternator or charger, but be sure to not overcharge the battery as this can damage it.