My First Solar Powered Boat Project

[SolarCanoe]

Hello All!

I am in the early stages of putting together an electric boat. I have searched the net to get some answers to questions I have but I am still not sure I am on the right track. I am an electronics technologist so I do understand the basics of Ohm's Law etc. I finally decided I would have to join a forum and outline my plans and get some feedback on my plans so far.

Background Info: My wife and I purchased a trailer in a seasonal campground and now have access to a very nice lake to go canoing on. We have a little 12 ft canoe that has been in the garage for 15 or more years. While we liked the opportunity to spend some time on the water we found the canoe less stable than we remember and decided to make some sort of outriggers. While researching that I ran across examples of people using trolling motors to power their canoes. Thus began this new project.

My plan is to make a very light weight canopy to keep the sun off of us, so naturally I started looking into solar panels. Long story short, I made a very low offer for 8 50 watt semi-flexible solar panels off of ebay and much to my surprise it was accepted so now I have 400 watts worth of solar panels for my canopy.

I plan to get a Minn Kota Enduro Max 40 trolling motor. It can produce 40 lbs of thrust and given 1 amp per lb thrust could draw as much as 40 amps full out. The current drops off quite quickly and at more moderate speeds will be down around 10 amps or less. This motor employs a maximizer circuit (ie, PWM) speed control that can extend battery life significantly over a conventional speed control on lower speeds. At full speed the currentt draw is the same.

I have found a 40 amp MPPT Solar Charge Controller on ebay, Tracer 4210RN, that is rated at 40 amp maximum battery current and 20 amps maximum load current. This does not seem like it is adequate since the motor can draw up to 40 amps and the max load current is only 20 amps.

I have also found some nice retro round analog amp and volt meters on ebay. I thought I would go for a nostalgic aircraft cockpit look and have an amp meter on the solar panels, battery, and load. The battery meter will have to be a +/- 0-50A meter and the other two can be 0-50. I know I probably don't need 50A range but the next range down is 20 amp which is probably too low. I would also add three voltmeters.

Equipment Summary:

Solar Panels 400 watts (8 x 50 watt).

Minn Kota Enduro Max 40 Trolling Motor (40 lbs thrust, max 40 amps).

Tracer 4210RN 40 Amp MPPT Solar Charge Controller.

Some retro round meters to monitor current draw and voltages.


My Questions:

1. I have already ordered the solar panels. 8 50 watt panels. I decided to go this way so that a panel failure represents less of the total. Vm=18V Im=2.78A (Voc=22.19 Isc=3A). Should I simply connect them all in parallel, or would there be an advantage in connecting them as 4 groups of 2 in series then all the groups in parallel to up the Vm to 36V? If I stick with the 18v parallel arrangement will a regular charge controller be almost as good as a MPPT type?

2. Should I connect the trolling motor to the battery or the load connectors on the charge controller. If the motor is connected to the battery will the panels supply current to the motor once the battery is dead? If the battery is fully charged and the solar panels can supply enough current to drive the motor will the battery remain unused until the solar panel power drops due to a lack of sunlight? Should I try to find a charge controller that can handle a 40 amp load?

3. Give the overkill of solar panels I am thinking I won't need a very large battery, maybe a 75 Amp Hour deep cycle battery would be enough. Assuming a battery rated at 75 AH is really only good for about 40 amp hours and that I would keep the motor current under 20 amps I assume that gives us about two hours to get home if we stay out after dark. Are these reasonable assumptions?

4. I'm sure I have forgotten something so please bring anything else I should consider to my attention.

Thanks in advance for any answers and comments

Todd

[Wy_White_Wolf]

1. Parralel/series would be better. More efficient and smaller wiring.

2. I'll let the others more knowledgeable than me answer.

3. Batteries have minimum/maximum charge/discharge rates. FLA - C/8 to C/12, AGM - C/4 to c/12
With thw 40 Amp load possible you need at least a 320AH FLA or 160AHAGM.

WWW

[SunEagle]

Using solar panels on a moving boat will not get you the power need to properly charge your battery due to the constant movement of the boat and sun.

It would be better to have them mounted on a permanent structure properly aimed at the sun for best absorption of light. You can then charge your battery on land and then move it to your boat for use. This way you can also have a second charger powered by a generator to charge your battery if the solar panels don't get you to full charge. If you hadn't already ordered your solar panels I would have suggested you don't and just use a stand battery charger on your battery. Using solar to charge batteries is the most expensive way to do so.

Also before you size your charge controller you need to properly size your battery based on the number of hours you want to run your motor. The manufacturer should be able to help you size your battery based on their motor specs but I don't think the 75AH size that mentioned will get you very much in the way of use. The battery should be much bigger.

[FloridaSun]

Hello All!

I am in the early stages of putting together an electric boat. I have searched the net to get some answers to questions I have but I am still not sure I am on the right track. I am an electronics technologist so I do understand the basics of Ohm's Law etc. I finally decided I would have to join a forum and outline my plans and get some feedback on my plans so far.

Welcome Todd, You've picked the right forum to join.
"Give the overkill of solar panels I am thinking I won't need a very large battery, maybe a 75 Amp Hour deep cycle battery would be enough."
Battery size will depend on your motor and use of it, not the panels.
'semi flexible' solar panels... maybe not a good idea for a canopy as you might need more structure (heavier) to support them. Suneagle's thought of a shoreside power station might be wise.
You might consider purchasing a 24v motor instead of that 12v. Morningstar's 15amp MPPT @24v would work with the 400w of panels you've committed to with a pair of 100ah marine batteries, they're cheap. If you are out until dark and it takes you two hours to get home.... better bring the paddles too. You'll get little charge from the panels except during mid day and most likely run your batteries low by then. Your 'lack of sunlight' will be around 2pm-3pm on a clear day. Remember your charge controller will need to be kept dry, no water splashes, no rain, but still ventilated for heat dissipation.
The trolling motor should be connected directly to the batteries.
Being in a seasonal campground with trailer... where will you store this boat? Have a boathouse or shed to drag it to? You might consider the possibility someone might find your PV system a fun toy to play with while you're away if it's left alone without protection/security. Also, the battery will need to be kept charged over the winter while not in use.... and too, those thin film panels will last much longer if kept out of the sun half the year.
I live on a lake year round, one thing that keeps me from playing with this solar panel canoe idea is wind possibility. A solar canopy on a canoe might need strong outriggers on both sides to prevent a gust from sending all to the lake bottom.
Be safe, have fun.

[SolarCanoe]

Thanks for the replies!

The batteries I have been considering are from CanadianTire. The Nautilus Marine Deep Cycle AGM type. There is a Group 24 and a Group 31 battery.

I was inspired by the following examples of electric boats:

The Little Solar Boat

The launching of the Sienna Solar Boat

Tritolyte Solectric 25 - electric boat test run

Minnkota Endura C2 trolling motor pushing a 17.5 BWCA Cruiser Canoe

SOLAR POWERED INFLATABLE BOAT PONTOON

So it's not a new idea but it sure looks like fun.

I see where I could buy a fairly wide inflatable boat for around $1400 CAD. That might make a better platform for this project.

[Naptown]

The downside to the inflatable is it will take much more power for the same speed than the canoe. Also when the battery's are dead a lot harder to row than paddle a canoe

[inetdog]

The downside to the inflatable is it will take much more power for the same speed than the canoe. Also when the battery's are dead a lot harder to row than paddle a canoe

On the other hand, an inflatable is less likely to sink from the weight of the batteries if you overturn it. It is hard to add enough flotation to counteract the weight of batteries large enough to propel the boat very far.

You should not think of the batteries as just a buffer while the panels provide most of the power while the boat is in motion. The energy balance just will not work out.
So look at the range and speed you need between charges and calculate the battery size and weight you need, not counting on any panel contribution.

If you have the money for it, this is an application for which expensive but correspondingly smaller and lighter Lithium batteries (I recommend Lithium Iron Phosphate, LiFePO4) ) could possibly make sense. They are available as batteries for motorcycles and for electric bicycles, but would need a slightly different charging system for best performance.

[tylertim]

A solar powered boat! Never really heard of that idea - but now it is in my head Very interesting!

[russ]

If you watch you can see solar panels on all types of things from boats to airplanes. Practical? No way but it makes nice eye candy for the greens to go "oh and ah" about.

[russ]

If you watch you can see solar panels on all types of things from boats to airplanes. Practical? No way but it makes nice eye candy for the greens to go "oh and ah" about.

[SunEagle]

Unless you have a very stable platform a solar panel will not produce it's rated output. You can easily duplicate a rocking boat on land with your panel and measure the amount of current it is putting out while moving or while being very still directly pointed at the sun. While moving, the output will vary greatly as compared to a fixed location.

To get a significant output of charge from moving pv panels requires more panels than a fixed setup. More panels will require more mounting space and on a narrow boat more instability. You would need a set of outriggers to keep the boat balanced or it can easily tip over. Those outriggers will then produce more drag which requires a bigger motor which requires a bigger battery which requires more panels. Not a good spiral to get into.

There was one video in an early posting showing the Minnkota Endura C2 trolling motor on a canoe. It was pretty slick the way he installed quick disconnects for his battery and motor connections. He didn't use a solar panel to charge his battery. He used a power grid connected charger. He could have used a solar panel charger but it would be better if it was installed on land where he could charge his battery.

If you are worried about running out of power than it would be smart to have a second battery on board that can be used when the first one runs out.

[SolarCanoe]

It Started With Outriggers

This whole thing started when I was looking into DIY canoe stabilizers/outriggers. I have done some experimenting with outriggers that use pool noodles as the pontoons. My test rig worked much better than I had expected. I am now in the process of making final versions of this sort of outrigger. I also rigged up a simple motor mount and we tried out a Minn Kota Traxxis 45 lb thrust trolling motor. I used the deep cycle battery from the trailer we purchased this summer. I suspect it is 7 years old and never really drawn on as the trailer was permanently hooked up to the grid. It was great for about 20 minutes and then died. It was enough for us to know we really liked the quiet motor and how fast it could push the canoe.

The 50 watt semi-flexible solar panels have arrived. They are quite light and all together weigh about 30 lbs. I should mention that we would be making some sort of canopy anyway so now I will make it using these light flexible panels. Now I need to figure out how to test them. I guess I should expose them to some sun light with some sort of load and see what sort of voltage and current they produce.

I hope to try out the final outriggers this weekend before it gets too cold here. I will try to post some photos of the canoe with the outriggers.

[SunEagle]

This whole thing started when I was looking into DIY canoe stabilizers/outriggers. I have done some experimenting with outriggers that use pool noodles as the pontoons. My test rig worked much better than I had expected. I am now in the process of making final versions of this sort of outrigger. I also rigged up a simple motor mount and we tried out a Minn Kota Traxxis 45 lb thrust trolling motor. I used the deep cycle battery from the trailer we purchased this summer. I suspect it is 7 years old and never really drawn on as the trailer was permanently hooked up to the grid. It was great for about 20 minutes and then died. It was enough for us to know we really liked the quiet motor and how fast it could push the canoe.

The 50 watt semi-flexible solar panels have arrived. They are quite light and all together weigh about 30 lbs. I should mention that we would be making some sort of canopy anyway so now I will make it using these light flexible panels. Now I need to figure out how to test them. I guess I should expose them to some sun light with some sort of load and see what sort of voltage and current they produce.

I hope to try out the final outriggers this weekend before it gets too cold here. I will try to post some photos of the canoe with the outriggers.

Looking forward to the pictures of the new design.

[SolarCanoe]

Outrigger Photos

I finished fabricating the new outriggers, and here are a couple of photos.IMG_0389 - small.JPGIMG_0390 - small.JPGIMG_0391 - small.JPG

I inserted some 1" aluminum tubing in some parts to strengthen it. These outriggers are 24" out from the sides of the canoe. I am also working on a set of arms that will allow the pontoons to be retracted and extended from 1 - 2.5 feet. That's right I am shopping for some 18" linear actuators. Then there are my ideas for retractable wheels and a motor deploying mechanism. But for now I have some outriggers to test on Saturday.

[SunEagle]

I finished fabricating the new outriggers, and here are a couple of photos.[ATTACH=CONFIG]3239[/ATTACH][ATTACH=CONFIG]3240[/ATTACH][ATTACH=CONFIG]3241[/ATTACH]

I inserted some 1" aluminum tubing in some parts to strengthen it. These outriggers are 24" out from the sides of the canoe. I am also working on a set of arms that will allow the pontoons to be retracted and extended from 1 - 2.5 feet. That's right I am shopping for some 18" linear actuators. Then there are my ideas for retractable wheels and a motor deploying mechanism. But for now I have some outriggers to test on Saturday.

Nice. Is that blue pipe insulation or those noodle things that people use in pools? That stuff will get brittle in the sun so be careful you don't lose your float material.