What is the maximum voltage drop when the network is powered from the battery?

• A. 0.75 Volts
• B. 2.5 Volts
• C. 1.17 Volts
• D. 3.0 Volts

Answer: (C)

Voltage on an NMEA 2000 network drops along the power trunk due to the resistance of the conductors and the current drawn by all devices on that trunk. The farthest device experiences the largest drop because it includes the cumulative resistance along the path from the battery to that node. The key is using V = I × R for the worst‑case path and ensuring the resulting voltage at the far end stays within the network’s acceptable operating range.

In the given network, using the provided currents and conductor resistances, the calculated worst‑case drop from the battery to the farthest node comes to 1.17 volts. So the maximum voltage drop when powered from the battery is 1.17 volts, meaning the farthest node voltage will be about battery voltage minus 1.17 V, still within typical operating limits.