What is true about VRLA batteries?

The statement that VRLA (Valve-Regulated Lead-Acid) batteries are usually connected by bolted terminals in series strings reflects an important aspect of their configuration. VRLA batteries are commonly used in applications where space is limited and a sealed battery design is advantageous, such as backup power systems or renewable energy storage. When connected in series, bolted terminals provide a secure and reliable electrical connection that helps maintain the integrity of the overall battery system.

In a series configuration, the voltage of each battery cell adds up to provide the necessary voltage for the application, making bolted connections essential for ensuring stable performance under different load conditions. This type of connection minimizes resistance in the electrical circuit, thus reducing the risk of overheating and potential failure.

The other options misrepresent characteristics of VRLA batteries. They do not require annual specific gravity testing since they are sealed and designed to minimize maintenance. While the lifespan of VRLA batteries typically falls within the 5-10 year range, it isn't universally defined across all brands and conditions, making that statement less definitive. As for the venting, VRLA batteries have controlled venting mechanisms that allow gases to escape in the event of excessive pressure but generally seal under normal operating conditions, contradicting the idea that they have a vent