Voltage drop cancellation

A method to bypass a voltage drop, the method comprising:

• allowing electric current to flow from a battery to a load and preventing electric current from flowing to the battery, the electric current having a voltage drop between the battery and the load, the battery comprising a non-rechargeable battery;
• detecting an absence of electric power from an electric power source, the electric power source providing electric current to the load when electric power from the electric power source is present;
• detecting that a voltage of the battery has fallen below a predefined level;
• bypassing the voltage drop in response to detecting the absence of electric power from the electric power source and that the voltage of the battery has fallen below the predefined level, such that the electric current from the battery reaches the load without the voltage drop;
• and
• delivering, to the load, electric current used to detect an absence of electric power from the electric power source.

An apparatus to bypass a voltage drop, the apparatus comprising:

• a protection module configured to perform a diode function, an anode of the protection module electrically coupled to a battery, a cathode of the protection module electrically coupled to a load such that the protection module allows electric current to flow from the battery to the load and prevents electric current from flowing to the battery, the batter comprising a non-rechargeable battery, the protection module comprising a voltage drop between the battery and the load;
• a power source detection module configured to detect an absence of electric power from an electric power source, the electric power source providing electric current to the load at the cathode of the protection module when electric power from the electric power source is present;
• and
• an output voltage detection module configured to detect that a voltage of the battery has fallen below a predefined level;
• a switch electrically coupled to the anode of the protection module and the cathode of the protection module such that the switch and the protection module are disposed in a parallel configuration, the switch configured to close in response to the power source detection module detecting the absence of electric power from the electric power source and the output voltage detection module detecting that the voltage of the battery has fallen below the predefined level, such that electric current from the battery reaches the load without the voltage drop of the protection module;
• wherein electric current flowing through the power source detection module is delivered to the load.