In the case of the Ducati Monster, the battery is not located under the tank. Instead, it is typically located underneath the seat. To access the battery, you would need to remove the seat by following the manufacturer's instructions or consulting the owner's manual for your specific model of Ducati Monster. The battery is usually secured in a battery box or holder, which can be easily accessed once the seat is removed. Remember to take necessary precautions and follow safety guidelines when handling the battery, such as disconnecting the negative terminal before any maintenance or replacement work.