The invention claimed is:1. A battery monitoring system, comprising:a housing having an input port, an output port, and a communication port, the housing to enclose a printed circuit board (PCB);an input terminal to extend through the input port of the housing and electrically connect to a positive terminal of a battery;an output terminal to extend through the output port of the housing and electrically connect to the input terminal and a primary load;a transducer communicatively coupled to the PCB, the transducer to sense an electric field generated by a current flowing from the positive terminal of the battery through the input terminal to the primary load and a secondary load;a relay communicatively coupled to the PCB, the relay configured to selectively prevent current from reaching the secondary load;a control link with first and second ends, the control link to extend through the communication port of the housing, the first end of the control link communicatively coupled to the PCB; andan interface module coupled to the second end of the control link, the interface module configured to indicate a status of the battery, wherein the status of the battery is based on the sensed electric field, the status of the battery including one or more of a current charge capacity of the battery as a percent of an original change, capacity of the battery, a temperature of the battery, and an estimated amount of time until a supply voltage of the battery drops below a predetermined value.2. The battery monitoring system of claim 1, the interface module to cause the relay to prevent current from reaching the secondary load based on the status of the battery.3. The battery monitoring system of claim 1, the primary load comprising a refrigeration unit.4. The battery monitoring system of claim 1, the interface module coupled to the PCB.5. The battery monitoring system of claim 1, comprising:a first gasket disposed between the input port and the input terminal for forming an environmental seal between the input port and the input terminal;a second gasket disposed between the output port and the output terminal for forming an environmental seal between the output port and the output terminal; anda third gasket disposed between the communication port and the control link for forming an environmental seal between the communication port and the control link.6. The battery monitoring system of claim 1, the interface module communicatively coupled to an alarm, the alarm comprising audible or visual alert in response to a determined status of the battery.7. The battery monitoring system of claim 1, the interface module communicatively coupled to a display and the interface module configured to indicate the status of the battery on the display.8. The battery monitoring system of claim 1, the interface module communicatively coupled to a user interface to receive user input.9. The battery monitoring system of claim 8, the interface module configured to indicate the status of the battery on a display in response to the user input.10. An apparatus, comprising:a housing having an input port and an output port, the housing to enclose a printed circuit board (PCB);a stud including an input terminal to extend through the input port of the housing and electrically connect to a battery, an output terminal to extend through the output port of the housing and electrically connect to a primary loada transducer coupled to the PCB and positioned on the PCB such that at least a portion of the transducer is located directly adjacent the stud, the transducer to measure a current in the stud; andan interface module coupled to the PCB and configured to indicate a status of the battery, wherein the status of the battery is based on a sensed electric field, the status of the battery including one or more of a current charge capacity of the battery as a percent of an original change, capacity of the battery, a temperature of the battery, and an estimated amount of time until a supply voltage of the battery drops below a predetermined value.11. The apparatus of claim 10, the input terminal and the output terminals being of different sizes compared to each other.12. The apparatus of claim 11, the input terminal having threads comprising a first thread size and the output port comprising threads having a second thread size, wherein the first and second thread sizes are different from each other.13. The apparatus of claim 11, the stud comprising at least two different thread sizes, the input terminal and the output terminal comprising a first thread size of the at least two different thread sizes.14. The apparatus of claim 10, the stud formed from a single piece of conductive material.15. A method, comprising:measuring a current from a battery with a Hall Effect sensor, the current powering a primary load and a secondary load;determining a status of the battery based on the measured current;comparing the status of the battery to a predetermined value;activating a relay when the status of the battery is below the predetermined value, activation of the relay to prevent the current from powering the secondary load; andindicating the status of the battery via an interface module, the status of the battery including one or more of a current charge capacity of the battery as a percent of an original change, capacity of the battery, a temperature of the battery, and an estimated amount of time until a supply voltage of the battery drops below a predetermined value.16. The method of claim 15, comprising receiving the predetermined value via an interface module comprising a user interface.17. The method of claim 15, comprising adjusting the predetermined value based on input received via the interface module.18. The method of claim 15, comprising activating an alarm when the status of the battery is below the predetermined value.