Stacking batteries, also known as connecting batteries in series or parallel, can serve different purposes depending on the configuration. Here’s a detailed explanation of both methods: Series Connection Purpose: Increase Voltage How it Works: When batteries are connected in series, the positive terminal of one battery is connected to the negative terminal of the next battery. Result: The total voltage is the sum of the voltages of each individual battery, while the capacity (measured in ampere-hours, Ah) remains the same. For example, if you connect two 1.5V AA batteries in series, you get a total voltage of 3V. Applications: Devices that require higher voltage than a single battery can provide. Power tools and electric vehicles often use series connections to achieve higher operating voltages. Parallel Connection Purpose: Increase Capacity How it Works: When batteries are connected in parallel, all positive terminals are connected together and all negative terminals are connected together. Result: The total capacity (Ah) is the sum of the capacities of each individual battery, while the voltage remains the same as a single battery. For example, if you connect two 1.5V AA batteries with 2000mAh capacity each in parallel, you still get 1.5V but with a total capacity of 4000mAh. Applications: Devices that require longer run times without increasing voltage. Backup power supplies and renewable energy storage systems often use parallel connections to increase storage capacity. Combined Series and Parallel Connections In some applications, batteries may be connected both in series and parallel to achieve both higher voltage and increased capacity. This is common in large-scale battery packs for electric vehicles and solar energy storage systems. Safety Considerations When stacking batteries: Ensure they are identical (same type, brand, age) to avoid imbalances that could lead to overheating or reduced lifespan. Use proper connectors and follow manufacturer guidelines to prevent short circuits or other hazards. By understanding these configurations and their purposes, you can effectively utilize stacked batteries for various applications requiring specific voltage or capacity requirements.