Solar Panels for Trolling Motor

[joanapalmer]

I have two solar panels on my yacht. That enough only for the fridge and conditioner.

 

[isaacs]

Have you considered using 4 - 6V golf cart batteries? These will tolerate deep discharges a lot better than the 12V RV batteries. Good luck, keep us posted!

 

[StarTed]

Latest update.

Due to the limited space in front I've maxed out the battery space. I could get more capacity using lithium batteries but they're over my budget.
I just received my 2 solar panels after a 6 week delay on a 5 to 7 day projected turn-around. The panels look great but will need quite a bit of extension to the top in order to fit them. They are for 12 volt use and tests showed a little over 10 amps each for their optimal output. Their efficiency is a little over 17%. The top of the pack at this time is a little over 22% so they're about where they should be for their price.

Meanwhile I took some advice and decided to try out my 2000i Honda generator up front and closing the front off while fishing for a few days. The generator has plenty of capacity to run the trolling motor but the charger can't keep up. It's 20 amps distributed meaning that it'll put out 10 amps to each battery but send more to a battery that may need extra for a maximum of 20 amps. That worked quite well but still required extra running when not using the trolling motor.

At this time I'm hesitant to install the panels on my boat and instead place them on top of my motor home.

I purchased some metering that I'll put on the trolling motor, batteries, panels and motor home. The metering should give me some useful information regarding current draw, voltage, power and energy from the batteries to the trolling motor as well as the output from the panels once installed in a horizonal position on top of the motor home. The metering resolution is 4 digits with accuracy not commensurate with the resolution in my opinion.

The delay in receiving the panels put me into the seasonal fall weather with rains, overcast and shorter daylight hours. Hunting season is beckoning me so it may take a while to get back on this.

I'll post the results which may be useful to others thinking about using solar panels on a boat. My roof space is just not large enough for all the panel space needed to get needed output.

Will follow up with some metering results as I get them.

 

[racerone]

Electricity is much mis-understood.----I often ask folks about generators.------You can buy a 5 HP generator at the hardware store.-----I then ask how much HP it takes to turn just 1 generator ( there are 8 of them ) where I used to work.------Some answers are way out.------The most common answer is 10,000 HP ------The correct answer is just over 1,000,000 HP and it blows people away.

 

[Scott Danforth]

Electricity is much mis-understood.----I often ask folks about generators.------You can buy a 5 HP generator at the hardware store.-----I then ask how much HP it takes to turn just 1 generator ( there are 8 of them ) where I used to work.------Some answers are way out.------The most common answer is 10,000 HP ------The correct answer is just over 1,000,000 HP and it blows people away.

gennys are not hard to understand...... its one box you put fuel in and it turns hooked up to another box you turn and electrons come out, all wrapped in a pretty box to sell to the customer.....

I used to be in charge of the Natural Gas gennys for Cummins in the 125kw to 1.2Mw range (50 liter diesels converted to NG) from 2003 to 2008. we did custom run and one-off diesel gennys (privat labeled, military, etc. up to 2Mw). Cummins Power-gen did the natural gas from single-digit ks's to the 125kw range and all the production line diesel gennys. most of the 60, 78 liter and 95 liter gennys were used for rentals (events/carnivals/construction) or peakers.

 

[racerone]

The generators I speak of are 800 Mega watt.-----The general public knows very little of the basics of the electrical grid system.

 

[StarTed]

Before retirement I worked 36 years for an electric utility, all in metering. We repaired, tested and calibrated AC watthour meters. That was our bread and butter. We also had a standards laboratory where we maintained AC watthour standards certified annually by NIST. We used Fluke to certify our DC standards.
Our laboratory was well recognized so we recertified AC watthour standards for other utilities up and down the west coats from California to Alaska and east through the Rockies.
It was interesting to find the various answers received when asking electricians "what is the difference between power and energy?". Electricians are good at what they do but that is not analyzing electrical functions. They work under varying voltages and are primarily concerned with current measured in amps or calculated from watts or kilowatt.
You can see, I do know the difference between accuracy and resolution. The meters I purchased for this project have greater resolution than accuracy but the resolution can help me see variations that may not be accurate but still helpful.
I'll report the readings so keep in mind that 1% +- 2 digits is the stated accuracy. Therefore a reading of 24.00 volts may actually be anywhere between 23.74 and 24.26. Sounds bad but that's what it is.

 

[Scott Danforth]

The generators I speak of are 800 Mega watt.-----The general public knows very little of the basics of the electrical grid system.

not an internal combustion powered..... my guess steam or hydro

 

[StarTed]

Those aren't the proper size for my boat.
Flea power is more of what I can fit.

 

[racerone]

Steam turbines.----The point is that many folks under estimate the size of solar panels to do what they want to do.

 

[StarTed]

around 30 years ago I hiked through the Beartooth Plateau in south central Montana with a solar panel on top of my backpack. It kept my Camcorder batteries charged for the trip. It was a week long hike at an average elevation of 10,000 feet above sea level. I had no regulation on the panel so I had to be very careful to keep from cooking the batteries. It worked to keep the batteries up and I got lots of video from that trip. I still have that panel in the basement.

 

[jrm7997]

There is a ton of information on mounting solar panels in the RV forums. I used super high adhesive tape called VHB to mount two panels to the top of my RV. No holes in the roof. However, you could weld a couple mounts onto your roof or bolt right through. Two other thoughts.

Can you tap into the alternator of your boat motor to charge the batteries while moving?

Buy one of these for about $15

 

[StarTed]

Thanks for the reply.
I've put the project on hold due to the drop in temperature. I now have the solar panels, controller and meters along with some extra heavy wires etc.
This winter when I use the boat I'm planning to put my honda generator out front in the boat. When I shut the door the cabin is sealed from any fumes and there are 2 large drain holes in the area where any heavier fumes will go out.
That said, I'm still planning to analyze the electrical needs for the trolling motor to help me determine if installing solar panels will make enough difference to make their installation worthwhile. I tend to go out for 2 to 3 days at a time without shore power so if solar panels aren't satisfactory maybe the Honda generator will work OK. I suspect the trolling motor to be a heavy user so the 2 gangs from the charger may not be enough.

More on this when the weather warms up again next spring.