Working with a battery can be messy and dangerous due to the acid and corrosion that is typically present in a battery. Spilling the acid on your clothes will likely ruin them, while getting it in your eyes is extremely dangerous. Baking soda can effectively neutralise the corrosive nature of battery acid and washing your clothes in a solution of baking soda and water can also minimise the damage from a spill.
Disconnect the battery from the device it has been in and/or from any terminals.
Combine three parts baking soda and one part water to form a paste.
Use the paste and one damp cloth to scrub the battery terminals and clean any corrosion from the inside of the battery connectors.
Use the second damp cloth to wipe off any excess paste that remains on the battery.
Allow the battery to air dry before reinserting it into a device and/or connecting it to terminals.
Use petroleum jelly to wipe down the terminals and connectors after the battery has been reconnected. This will help prevent more corrosion from occurring in the future.