native, an AC power converter can be used to avoid gain error due to poor battery durability. Switch to a square 9V battery only when there is no AC power supply available outdoors. When using an AC power converter for an extended time, we suggest you remove the battery from the compartment. This is because heating will result in battery leakage, and battery electrolyte will rust the circuit board, thus creating major damage. Furthermore, batteries are high pollution products and therefore by re.