Two or more of these in series from a battery?

Connecting two or more batteries in series increases the total voltage while maintaining the same capacity (amp-hour rating). For example, connecting two 1.5V batteries in series results in a combined voltage of 3V. This configuration is commonly used in applications requiring higher voltage outputs, such as flashlights or certain electronic devices. However, it is essential to ensure that all batteries are of the same type and charge level to avoid issues such as reduced performance or damage.