Frugal Boater: Solar Charge Controller Basics

With all but the smallest of solar panels, you’ll need a charge controller. A charge controller goes between the solar panels and the batteries. It’s job is to limit, or control, the power your panels put into your batteries.  This keeps you from destroying expensive batteries by overcharging. There are two types charge controllers.

Power Width Modulation (PWM) controllers are relatively inexpensive. They work by literally switching the panels on and off very rapidly. That works fine as long as your panel voltage is fairly close to your battery voltage. If you’re a weekend boater who just wants a small panel to keep your battery topped up while you’re away, a PWM controller might do the job. Using a PWM controller will limit the size panels you can use because they don’t have the capability to change the voltage, only turn it on and off.

Multi Power Point Tracking (MPPT) charge controllers are a big step up in performance  and price. These controllers actually adjust voltage/current in an attempt to wring the most power out of your panels. They also have the capability to step the panel voltage down to whatever your batteries need. An MPPT controller takes the 60 volts coming in from our panels and steps it down to our battery charging voltage (around 13.5). When the voltage comes down the amps go up, so very little power is lost in the controller.

Beware of cheap “MPPT” found on Ebay and the like. Some are actually PWM  controllers with “MPPT” printed on them. Since the charge controller is the heart of your system, and could prove dangerous to you and your batteries, it’s best to stick with a quality unit from a reputable manufacturer.

A standard system with one MPPT controller is striving to optimize all panels, meaning that during partial shading some panels are running higher and some lower than optimum. No panels are really performing their best because the controller is working with an average. This is where MPPT optimizers on each panel can be useful. In an environment where shading is unavoidable, this allows each panel to work independently for optimum results. Obviously no two systems and shade scenarios are identical, but tests with optimizers show that during partial shading power output can be increased by 15-25%. In an environment where partial shading can’t be avoided, and space is limited this can be important. That sounds a lot like a sailboat doesn’t it?

Related articles:

Solar Panel Basics

Pearl Lee Solar 1.0

Pearl Lee  Solar 2.0

Frugal Boater: Solar Panel Basics

Solar panels convert solar energy to electricity. A panel is a collection silicon wafers called “cells” wired together to get the required power and voltage. Ideally, all your panels should be exactly the same. In our case they are not, but they’re “close enough” since our old and new panels are all 280 watt, 60 cell panels.

A little spot of shade on the corner of a panel, or a thin line of shade from a rope might not seem like much, but it can drop the power output of the shaded panel significantly. This is because the voltage of the shaded cells drops, rendering them nearly useless. In older panels this shaded area can actually suck power from the sunny cells. Luckily newer panels have bypass diodes that disconnect and bypass the shaded area. The bad news is panels have only three or four bypass diodes, so even a small shadow can result in a large drop in output. This is a big problem on sailboats with masts and rigging casting shadows. I’ve even seen panels mounted with straps over them!

We use mono-crystalline panels because they perform slightly better under less than ideal conditions. You can recognize mono panels because you can see the individual cells which are actually thin slices of a silicon ingot. Multi-crystalline panels are poured, so the entire panel will be one continuous sheet of  silicon, often with some multi-color light refraction. The performance difference is pretty slight, so don’t be afraid of multi-crystalline panels if the price is right.

Ideally, solar panels should be at a right angle to the sun’s rays. Doing so gathers maximum solar energy per square foot of panel. Static installations can easily approximate this, but on a moving boat it’s quite a challenge. I’ve seen a few articulated panels, but  to be effective they take some baby sitting. Most boaters just deal with less output from un-aimed panels.

Solar panels are usually wired in series (+ to -, – to +) to create “strings”. Wiring in series increases voltage, but not amps, so wiring is cheaper and easier because higher amps requires thicker wire. Although there used to be problems with shade on one panel having a negative impact on the entire string, bypass diodes effectively fixed that issue. Strings are then wired in parallel (+ to +, – to -) at the charge controller to keep voltage at manageable levels.

Related articles:

Charge Controller Basics

Pearl Lee Solar 1.0

Pearl Lee Solar 2.0


Iuka, MS and Lake Pickwick


We had a lot of fun meeting people and generally hanging out at Aqua Yacht Harbor.  Since they have loaner vehicles we got a chance to see the surrounding area, including Shiloh National Military Park. Of course we also found some other fun  and mischief.

We found a shark, even though we were still on the rivers. After looking around we decided this wasn’t the place we were looking for.

On down the road we found a wonderful little place, apparently owned by Big Foot(or is it Sasquatch?), but we weren’t sure what he was doing. We didn’t ask. The food and service were great though and the place had a very woodsy feel.  It’s on Highway 57 across the dam. You can’t miss it, just look for Big Foot.


AssWhaffle Yacht Club members Terry and Marlane showed us their beautiful motor yacht, treated us like family and gave us a boat tour of the area. This lead to a little detour for Pearl Lee, as you’ll see.

Wayne and Beth just “wanted to see what the sea gypsies were up to”. That chance encounter became a weekend of fun, laughter and several docktails. The boating community is full of wonderful people.

We really enjoyed our few days here, but eventually it was time to move on. However we had one more thing to do. A slight detour and one more night in the area was in order because Terry and Marlane showed us a hidden gem of an anchorage on Pickwick Lake.

A tiny cove with a waterfall. Completely protected, and even at winter pool it was 14 feet or so deep! Here’s a 360 degree video just after we anchored.

As you can see, being late in the season, we were the only boat here. Terry said it fills up on summer weekends though. This was such a beautiful spot we really hated to leave! There was even a steep trail to the top  the falls.

The night was lit up by a full moon. How perfect is that? It was like we had a full day of Zen.  We had a brief visit from a small power boat and a visit from a jet skier who just wanted a few minutes watching the water. What a place! Thanks Terry and Marlane, this was an awesome gift.

I’ll close with a video we shot from the base of the water fall.



While staying at Aqua Yacht Harbor we decided to take a short trip to Shiloh National Military Park.

If you go, we highly recommend the CD audio tour. It lets you see the various battle fields in chronological order while explaining the what’s and why’s.

Although the orchard is no longer an orchard and other vegetation has changed you get a clear idea of what went on.

Particularly interesting to us was the naval bombardment from the river, which we had just come down in Pearl Lee.

History comes alive in places like this. Although the cannons don’t thunder, and men don’t scream, the ancient echoes still seem to linger. Seeing places that you’ve only read about gives a much greater sense of what transpired here than any book or movie ever could.

The Shiloh National Cemetery is here as well. It’s good to go to places like this and reflect on our history and what so many of us owe to so few. This is hallowed ground and hopefully will be treated as such for generations to come.

Kentucky Lake to Iuka, MS


We left early in the morning with Deep Purple’s Smoke on the Water in our heads. We tried to catch the little swirling vortexes on video but were unsuccessful.

Fall was in the air, so it was time to head south again. Of course Kentucky Lake gave us plenty to see on our way. The landscape here is dominated by forests and stark cliffs.

Every now and then you get a reminder that this is a flooded river valley. Sometimes it’s just an old road that goes into the water, often used for boat launching nowadays. Other times it’s a bridge to nowhere, that once spanned the river.

Then there are dramatic reminders like this old grain loading dock. Once on the banks of the Tennessee River, it now sits flooded and surrounded by water. No one seems to know why this structure was left when the TVA tore down the other buildings before flooding the valley.

As we cruised along we saw all sorts of boats, and we often wondered how far they were going. Many were doing the Great Loop of the eastern US. We think this guy might have the perfect boat for cruising the river system. Shallow draft, low cost and all the comforts of home.

We saw catfish jumping (or maybe Asian carp again) along the way.

Anchoring in a quiet cove at night and then pushing on the next day.

The Tennessee River is truly God’s country with breathtaking scenery around every bend.

We were starting to see some fall colors, just a hint of what was to come. Of course that also meant cold weather was coming. With no real heater on the boat we had to keep moving.

We were still seeing eagles as this is their winter nesting area. Unlike us, they don’t mind the cold, but they do need open water to fish in. This pair of males seemed to be just hanging out together.

Mornings often greeted us with still water and brisk temperatures. You just can’t get tired of scenes like this. The only ripple on the water was made by Pearl Lee’s passing.

Of course we also saw where men encroach, but nature always wins. Someone has a real problem on their hands here.

We pressed on towards Pickwick Lake. This is another TVA project, smaller at 67 square miles, but deeper than Kentucky Lake. Pickwick Lake’s waters are often crystal clear.

At the Pickwick Lock we got a nice demonstration of discourteous boating, as a powerboat jumped the line to get ahead of us. We were then treated to a demonstration of how NOT to lock through by the same boater. During his, uh “maneuvers” we heard a few loud crunches. No one was hurt though.

We made it to Aqua Yacht Harbor Marina just as the sun was setting, directly in our eyes. For some reason they booked us into a covered slip with inadequate depth due to an underwater structure. We ended up docked next to another Endeavour, how cool is that? To their credit, when I mentioned the issue, they gave us a free night. Nice folks.


Kentucky Lake Exploring


After a little rest we decided to play in Kentucky Lake just a little bit. Kentucky Lake was formed when the Tennessee Valley Authority dammed the Tennessee River, flooding a 250 square mile area. This results in a “lake” with more little coves to explore than you can count.

This is a truly beautiful area. The TVA relocated graves there were going to be underwater. This bit of cemetery, once a hilltop, is now an island, accessible only by boat. Since they would remain above water, they were left here. What a beautiful spot to rest.

We spent the day exploring, and learning. We weren’t sure what this was, but we saw several. We later found it was bryozoans which filter the water for food, keeping it nice and clear. Cool, huh?

With the water at “winter pool” level, a lot of rocky shoreline was exposed. This normally submerged beaver hut was exposed and abandoned.

We also found lots of tracks in the mud, but being city slickers, we weren’t sure what made them. Probably raccoons, maybe beavers.

Of course every kind of wildlife abounds here, especially in the “Land Between the Lakes“, a 170,000 acre recreation area separating Kentucky Lake and Lake Barkley. We’re always on the lookout for butterflies and spotted a few Eastern Commas like this one. The coloring and wing shape help camouflage them among fall leaves. This one may not have gotten that memo.

We can only imagine what this place looks like when fall colors are unleashed on the hillsides. We had a fantastic day exploring, and could easily spend a long time here without tiring of the scenery and exploration opportunities. We spent a quiet night at anchor in a little cove before moving on once again.


Cumberland River Junction to Hardin, KY


Another early morning start, heading up the Cumberland River. The Cumberland is a gentle, winding and very scenic river. We definitely recommend this route for the scenery.

Our modern GPS’s are extremely accurate, but we’re still often using chart (map) data created by men wearing buckskins while paddling canoes. Watch where you’re going and verify visually what you see on the screen. Here the chart says we’re on land, but we weren’t. Had we followed the chart, we may have been.

Every bend in the river revealed more beauty. What a place! We just cruised along and took it all in. There were interesting bluffs and rock formations everywhere, mirrored by the calm water. It was fun to watch our ripples as we motored along as if we were the only people on the river.

There is still barge traffic here, but we didn’t see any moving all day. We did come across some barges being loaded. With some rocks the size of washing machines, and not all of them landing in the barge, we gave them a respectfully wide berth.

Of course we were only doing enough of the Cumberland to get us to Lake Barkley and Kentucky Lake, so our time on the Cumberland was short.

Before we knew it we were approaching the Barkley Lock and Dam. A somewhat new experience for us, we’d be going UP this time. 57 feet of up! Here’s Kristi using the boat hook to keep our bow off the wall. I’m doing the same at the stern. Powerboats with straighter sides seem to lie against the wall with as much prodding.

After our ride up, we found ourselves on Lake Barkley. We tried to anchor in a little cove, but after three tries we gave up. Locals later told us that particular cove is a bit of mud over solid shale. No wonder we were dragging. Frustrated, we took the cut over to Kentucky Lake and headed for Kenlake Marina.

Kenlake was very accommodating, even charging us less when they found out we wouldn’t need electricity. At 75 cents a foot per night, Kristi made a command decision and booked us for two nights.

Metropolis, IL to Cumberland River Junction

At first light we were heading farther up the Ohio River, bound for the Cumberland River. The current was gentle and we were making almost 6 kts speed over ground. Did you ever see something and just know that it was designed by a man? We had one of those moments not far from Metropolis.

The day was fairly uneventful, other than meeting a few tows. The Ohio is wide, with little current though,so drama was at a minimum. One of the more unusual sights was this old river boat, being torn apart for salvage.

We stopped for the night at a place called Cumberland Island Towhead, just half a mile from where the Ohio and Cumberland rivers meet. In the still water we saw hundreds of fish (we think Asian Carp) feeding at the surface.

We did some beer drinking… uh fishing. She caught and released a couple small catfish. We generally just relaxed and watched the sunset.  The perfect end to a relaxing day.

Sitting well out of the channel in a beautiful protected anchorage. Watching the setting sun as the tows go by. This is why we made this trip.

Grays Point, MO to Metropolis, IL


Another early morning departure. We had anchored, once again, in a muddy river bottom, so Kristi had a mess to clean up. The hose you see is our “raw water washdown”. It pumps water from around us so we don’t use our good water for things like anchor and deck rinsing.

Once we headed out into the strong Mississippi current we would be committed. There could be no stopping, so we made a Security call on the VHF as we left Little River Diversion to warn any boating traffic on the Mississippi that we were about appear. No problem, since it turned out no one else was around, and we made our way downstream.

By now we were seeing eagles all day, but each one was still a thrill. We love seeing these majestic creatures in their natural habitat.  “I guess he’d be a poorer man if he never saw an eagle fly.” – John Denver.

Still on the Big Muddy for a bit, Tom continued to quarrel with theriver over who was steering the boat. So much so that we started to think something was wrong with our steering.

With fast current comes high turbulence and steering was a full time job. While countering the swirling water, we also had to watch out for debris, sometimes whole trees; and deadheads, almost invisible floating just under the water. Channel markers get moved out of position and even do a magical disappearing and reappearing act!

The upside to all that current is speed! We were doing 218 miles of Mississippi River in just two half days and a full day. Notice the Speed Over Ground (SOG) at 12kts (13.8mph)!

Around noon we made a sharp left turn onto the Ohio River. Suddenly steering was easy again, and our speed dropped to normal sailboat speed of 6-7kts.

We decided to stop at Metropolis. We read about a good anchorage between the casino and bridge, near an old boat launch. Perfect, we thought, we can land the dinghy and go see the big Superman!

What we found was a homeless camp next to the ramp, so we decided  not to leave either boat unattended. After anchoring bow and stern, to insure that we wouldn’t swing into shore or out into the river we were treated to another beautiful sunset. With the mighty Mississippi behind us, we were looking forward to some easy cruising and beautiful scenery ahead.


Our Endeavour 43