What device is necessary to convert DC power from batteries into AC power for servers and routers?

To convert direct current (DC) power from batteries into alternating current (AC) power, an inverter is needed. An inverter functions by taking the stable DC power supplied by batteries and transforming it into the fluctuating AC power required by most servers and routers. This process is crucial since many electronic devices are designed to operate on AC power, which can provide varying voltage and frequency as needed.

Inverters are commonly used in renewable energy applications, backup power systems, and uninterruptible power supplies (UPS), allowing for the effective use of stored battery energy in devices that rely on AC current. The technology utilized in an inverter enables it to efficiently convert the current while maintaining the necessary power quality needed for sensitive electronic equipment, such as servers and routers.

Other devices mentioned in the options serve different purposes. A transformer, for example, is designed to change the voltage level of AC power but does not convert DC to AC. A rectifier does the opposite of what is needed here; it converts AC to DC. A generator typically produces AC power from mechanical energy, but it does not convert DC power from batteries. Thus, the inverter is the correct choice for the conversion of DC to AC power in this context.