It is recommended to charge a new riding mower battery before its first use. However, some riding mower batteries may be partially or fully charged when purchased. You can verify the battery's charge level using a voltmeter. If the voltage reading is below the manufacturer's recommended level, you should charge the battery before operating your riding mower.
By charging the battery before its first use, you can ensure that it has enough power to start the mower and operate effectively. This can help prevent damage to the battery and extend its lifespan.