What is the recharge time for a secondary battery when using a non-switched primary source?

The recharge time for a secondary battery when using a non-switched primary source is typically around 48 hours. This timeframe is based on standard practices for charging lead-acid batteries and other common types of secondary batteries that might be used in alarm systems.

The reason why 48 hours is the correct answer lies in the charging characteristics and the need to ensure that the battery is fully charged without being overcharged. Secondary batteries, depending on their specific chemistry and capacity, require a certain amount of time to charge from a depleted state. When a non-switched primary source is used, it continuously charges the battery without the interruption of a switch, which allows for a steady flow of current.

This timeframe also takes into account various factors such as the battery's size, type, and the charging current supplied by the primary source. While different batteries might exhibit varying recharge times, the common standard for many secondary batteries under similar conditions is approximately 48 hours for a full charge. Longer charge times can result in extended battery life and performance, which is critical in alarm systems that rely on backup power.

Other time options such as 24 hours, 36 hours, or 60 hours may not align with the standardized practices for many alarm systems, which emphasize a balance