How long should a technician wait after charging a battery before checking the specific gravity?

Waiting 15 minutes after charging a battery before checking the specific gravity is important to obtain an accurate reading. This time allows the electrolyte to stabilize after the charging process. During charging, the chemical reactions within the battery cause the electrolyte to heat and can temporarily affect the specific gravity measurement. By allowing the battery to rest for this period, you ensure that the electrolyte has uniform density, resulting in a more reliable specific gravity reading that reflects the battery's state of charge.

This practice contributes to more effective diagnostics and maintenance of the battery, ensuring that technicians can make informed decisions about battery health and performance. Taking readings too soon could lead to misinterpretation of the battery's condition, which can impair repair decisions or lead to unnecessary replacements.