Charging woes solved - off-grid!

It’s been many years since I’ve posted an update. I can’t believe the Electric Yacht system will be 14 years old in July.

When I installed the electric motor I kept the boat in a marina with shore power. Due to lake level inconsistently (and one season of single use) I jumped over to a mooring field run by Dane County Parks. This posed some complications with charging the battery bank. I now had to bring the boat into the docks, hook up a portable generator and let it run for hours until the charge process was complete. I made this move only a few years after installing the motor, and over the years at the mooring field, my battery bank often went mis-managed due to charging hassles. I went through two AGM banks. A costly exercise.

The process became even more of a hassle recently with Park Rangers ramping up their stance on boats left unattended on the docks—no longer allowed—even on the one that is meant for overnight occupancy.

Two years ago I took the leap and swapped out the AGM battery bank with LiFePO4 (Battle Born brand). The cycles are much longer, and the weight difference alone is worth the price of admission. The AGMs affected the waterline, especially if I had a few more people on board than usual.

The last two seasons I was trying to troubleshoot my on-board battery charger. I found myself not even having to charge the batteries (they tend to see little use). This season, however, I realized the charger wasn’t working—I still have no idea why. Could be related to my generator, but even if it was working, it wouldn’t solve the inconvenience of hauling a generator to the dock, then sitting with the boat for 5 to 8 hours while charging.

A new charger geared specifically for lithium would’ve run me $200-$300, and would still require me to sit with the generator.

I decided to revisit the notion of wind and solar. A turbine has a few downsides—noise, permanent mount, possible vandalism due to the fact that they do generate noise, and fishermen tend to frequent the area. It’s not uncommon to find lures and line tangled and snared in mooring tackle or ropes on board. 

The last time I considered solar (9 or 10 years ago), I ruled it out due to the amount of real estate required by a solar array capable of charging a 48v battery bank. I began a conversation with an electrical engineer whom I met on an electric sailboat Facebook group. He mentioned a few game changers in today’s solar options: improvements with today’s flexible panels AND the existence of charge controllers which can boost voltage.

Flexible panels were always a compromise on wattage output. Not so much anymore! And with a properly paired charge controller/booster, I was able to find a system that would work.

The new charge controller is connected in the same manner as the old charger, and is about 43 lbs lighter. The panels can rest in the cockpit, out of straight line view of passers by. Just in case I do have to leave them connected for a few days, theft/vandalism is a little less of a concern.

Eco-Worthy 390W Solar Kit

This past weekend we went for a sail, and the battery reading was around 94%. I connected the panels and left them for a few days (we did have excessive cloud cover, so I gave it some more time than I typically would). I went out and checked afterward—100%. I can now say I’m totally off grid. 

The solar system was acquired through Amazon for about $250. It included three 130-watt panels, interconnecting wires, the charge controller/booster, wiring to batteries and generous amount of wiring to the panel array. I didn’t like the gauge of wire to the batteries, so I did end up getting something thicker (12 GA.)

The charger and wires stow in the same space as the previous charger, and the panels lay flat up in the v-berth when not in use. I could arrange them on deck to charge while sailing, I would just need to find a way to make them secure when boat is heeling, and cords might get in the way. 

Charger in compartment under chart table.

Charger close up

Two panels in cockpit while in use. Third is behind steering pedestal. 

Panels stowed in v-berth

System details: ECO-WORTHY 390W Flexible Solar Panel Kit; 1560wh/day Generation. (3) 130W Solar Panel +24V/36V/48V/60V/72V MPPT Boost Charge Controller.