A low voltage alert was flashed in the multifunction display during a recent trip from Charleston, S.C. to the Chesapeake Bay. The 12-volt power supply began to drop. The crew went to the tender, stripped its battery and charger, and used them to replace the failing battery as a temporary solution, but the smaller charger could not keep up with the big boat’s demand. As the night fell, the voltage dropped slowly until it crashed.
The crew was left flying blind after the failure of the radar, chartplotters and VHF radio.
Here’s what happened, how they handled troubleshooting, and how they repaired the system to add redundancies for the future.
Many excellent reasons exist for using higher voltages with a DC system. When 24 volts is used instead of 12, smaller wires can be used and the electrical efficiency will increase. The lighter-gauge wire can also help reduce weight on larger vessels, often by a significant amount.
Unfortunately, not all equipment can run at higher voltages. Most ,… but not all.