Some embodiments include an electrical system. In many embodiments, the electrical system can comprise a system input configured to receive a first power signal from an external power source. In the same or different embodiments, the first power signal can comprise a first voltage. In the same or different embodiments, the electrical system can comprise a system output electrically coupled to the system input. In the same or different embodiments, the electrical system can comprise a charger module electrically coupled to the system input. In the same or different embodiments, the electrical system can comprise a resistive component coupled between the system input and the system output. In the same or different embodiments, the electrical system can comprise a power storage device electrically coupled to the system output and to the charger module. In the same or different embodiments, the electrical system can comprise a sense circuit electrically coupled across the resistive component and electrically coupled to the charger module. Other embodiments are disclosed.