The specific gravity of a battery should be between 1.265 and 1.299 for lead-acid batteries. This range indicates that the battery is fully charged and in good condition. If the specific gravity is below 1.225, the battery is discharged and needs to be charged. If the specific gravity is above 1.299, the battery is. A good battery hydrometer readingis between 1.265 and 1.299. This reading indicates that the battery is fully charged and in good condition. If the reading is below 1.225, the battery is discharged and needs to be charged. If. Understanding your battery's specific gravity is crucial to maintaining its health and prolonging its lifespan. By using a battery hydrometer and interpreting the readings using a battery specific gravity chart, you can determine. The specific gravity of a fully charged 12v battery is between 1.265 and 1.299. This range indicates that the battery is fully charged and in good condition. If the specific gravity is below. The specific gravity in a 24 volt battery should be the same as in a 12 volt battery. The specific gravity range of a fully charged 24 volt battery is between 1.265 and 1.299. If the specific.