Windlass and Aft-System Lithium Battery Upgrade

After confirming that the new lithium battery was operating the connected equipment properly, I removed the two old batteries from Hunky Dory and took them home.

The aft toilet has continued to work very well with the new battery. It flushes noticeably faster and more strongly than it did with the old battery bank.

I installed the new Victron lithium battery in the starboard engine room and connected the windlass, aft toilet and sanitation system, and aft shower box. One of the old batteries measured approximately 13 volts, while the other measured only 8.6 volts. The failed battery had apparently been pulling down the entire bank and causing the aft toilet to operate slowly.

Two unidentified negative cables were connected to the old bank. I reconnected them during this first-phase installation, but they still need to be traced and identified.

I tested the aft toilet and confirmed that it flushed much better. I also tested the windlass at the dock by retrieving the anchor from the dock and seating it in the bow pulpit. The windlass operated properly while I recorded the smart-shunt readings.

Before installing the battery aboard Hunky Dory, I connected a small inverter and operated a 200-watt space heater as a test load. I reduced the battery from a full charge to approximately 70 percent, then recharged it with the charger set to 25 amps. It returned to a full charge in approximately two hours.

I set up the new battery at home and charged it fully with the plug-in charger. The charger progressed through its charging stages and finished in storage mode.

I also fabricated the necessary cables and installed a fuse for the charger, a smart shunt for battery monitoring, and a temporary 12-volt and USB outlet for testing loads.

I investigated the existing windlass wiring and found that the cable passes through terminal connections below the windlass inside the anchor rode locker. From there, it connects to a larger 1/0 welding cable that runs back to the starboard engine room.

Tracing this cable helped confirm how the windlass was connected to the existing battery bank and where the replacement battery could be installed. I also gathered the parts needed for the initial installation.

The existing starboard battery bank had been powering the windlass and aft sanitation equipment for several years. The aft toilet had begun operating slowly and sometimes would not flush, even after the bank had been connected to its charger.

I recorded the battery brands and model information and began planning a lithium replacement with improved monitoring and charging.