I will be working in Ely all this summer and will have my boat up with me. I was wondering if this is even a possibility or if anyone has tried this at all. Would be pretty convenient if I could get some off-grid power to charge up my batteries.
12 volt or 24 volt system? I dont have experience with solar charging, but its surely going to be a slow go. Obviously you are likely using your boat during the day when the solar charger would be at its best so not sure how much time on the charger you would get because once the sun goes down you are SOL. You would be better off getting a DC Alternator Charger like I have in my boat. It charges the trolling motor batteries while the outboard is running. Works fantastic. I spend a week on an island in Canada and dont have to plug in my trolling motor at all.
Stealth is the brand I have, but there are others, but I highly recommend Stealth. The owner even gives you his cell phone number in case you have issues.
It can work but you have to buy big enough equipment. Im sure others will chime in or you may find it searching the web. I was going to do this on my pontoon but my dock doesnt get sun much of the day. People on my lake have them for their lift batteries.
12v power drive at the moment unless I decide to upgrade. I would be working during the day most of the week so that would give me time to charge which was my thought process. They also look pretty cheap.
I will just be starting to wire up my boat after ice fishing ends here. This is also my first time doing any of this. Any recommendations for an onboard charger and batteries would be much appreciated. From my understanding what the charger will do is take power from your outboard’s alternator and use it to maintain the battery life of your trolling motor battery?
Any recommendations for an onboard charger and batteries would be much appreciated. From my understanding what the charger will do is take power from your outboard’s alternator and use it to maintain the battery life of your trolling motor battery?
Generally its not a great idea to use the same battery for your trolling motor and starting your outboard. Maybe you don’t have room for separate batteries, but if you do, I’d dedicate one as a cranking battery and use that for your outboard starter, electronics, pumps, lights, etc and then dedicate a deep cycle for your trolling motor. If you use the same battery, there is a risk of running the battery too low to restart the outboard.
As far as batteries, that’s a big can of worms to open up. There are three types: standard lead acid, AGM, and lithium. They range in price from 100 bucks all the way up to about 500 bucks.
From my understanding what the charger will do is take power from your outboard’s alternator and use it to maintain the battery life of your trolling motor battery?
Yes, that is how a DC Alternator charger works. However if you have a small outboard it may not have a large enough alternator to effectively charge the trolling motor battery.
If you are looking for recommendations on an onboard charger that you would use in conjunction with the solar panel, NOCO is an excellent choice.
A 100W panel at max/optimal production can do about 7ish amps at charging voltages. Most people use 10 amp chargers (per bank, which is important if you have more than one battery to charge) so that isn’t too bad for a single battery but you only have a couple hours of that per sunny day unless you manually track the sun.
If you are actually off-grid it’s certainly possible but you might need more panels. With 6x 100W of panels I can eke out 6-10 amps even on pretty overcast days where I’m surprised it works at all. It’s not cost-effective at all if you have grid power though.
Reef is correct in his statement. To clarify a little, any solar panel will charge the battery it’s just about how fast it will charge. Case in point if you used a 20w-30w panels they use for a boat lift battery and your battery was at 50% capacity it could take like 4 days to fully charge the battery. But if you had a 300w panel it may only take 6-8 hours to recharge the battery. My boat sits on a lift where I have no access to ac power and had looked at the same thing you are talking about. I believe I would have needed at least a 300W panel to get the battery recharged in a typical day. Problem for me was if I was fishing and not on the lift I couldn’t recharge the battery and solar doesn’t work at night. The panel do come with different voltage outputs, usually either 12v or 24v is most common, so you need to match up with your trolling motor voltage.
A “12V” panel optimally makes ~18V and a “24V” panel ~32V. It only matters if you are using a PWM charge controller which are the cheaper kind. You can’t charge a 12V battery with 18V so a PWM controller pulses on/off to lower the average voltage to what it needs to charge a 12V battery. It also requires that the voltage from the panel be higher than the charging voltage which is why a “12V” panel makes 18V. This is inefficient because you usually can’t use all of the power that the panel is making at peak and when the panel voltage drops below your charging voltage it stops charging.
An MPPT controller is a DC-to-DC converter that will accept whatever it is rated for and convert it to the correct output. My system, for example, is about 60V from the panels but charges 12V batteries. With MPPT you can use whatever panels you want as long as the voltage and current going to MPPT is within the specs of that controller.
Attached a screenshot of MPPT controller very early in the morning, not much light yet, where 6x 100W panels are only making 52W. The “solar” part is the input to the controller and the “battery” part is the output.
Screenshot_20220626-113646.jpg
You’d be better off carrying a small generator.
You’d be better off carrying a small generator.
I was also thinking about just doing that, I will have electric just might be nice for certain times if I am off the grid for a couple of days at a time. Will my 25 hp tiller be enough power for an onboard charger or do you need more horsepower than that?
What year/make/model outboard? The minn-kota single bank needs 12 amps minimum alternator output, which some 25 HP outboards can do – likely only at RPMs over idle or trolling speeds.
Are you confusing a standard on-board charger with an on-board *alternator* charger?
I was going to suggest comparing cost of just buying a generator.
Many sound happy with the honda knock-offs that are cheaper such as predator.
I suspect cost will be comparable to a solar system of decent size.
A 10-15 Amp charger and generator will most likely fill you up in a tank of fuel ~10hrs for a 1000-2000 Watt generator
Are you confusing a standard on-board charger with an on-board *alternator* charger?
Most motors will have an alternator built into it that while running will be charging your starting battery. If you are making very short runs, have extra electronics, ect, this might not be enough to even keep your starting battery fully charging without aid of another charger. An add on “on-board” charger is just a 120v charger that is usually fastened to your boat so that all you have to do when done using your boat is plug it in. You can get them in however many “banks” you want depending on the amount of batteries you are trying to charge. My advice if you have a single 12v trolling battery and a 12v starting battery is to get a 2 bank charger so that you know your always topped off when you hit the water. I have had good luck with the Minnkota digital on-board chargers. I like that they have separate indicator lights for each bank to know what state of charge they are at.
I would vote small generator. Cheaper and will charge your battery any time you need.
tswoboda wrote:
Are you confusing a standard on-board charger with an on-board *alternator* charger?Most motors will have a charger built into it that while running will be charging your starting battery. If you are making very short runs, have extra electronics, ect, this might not be enough to even keep your starting battery fully charging without aid of another charger. An add on “on-board” charger is just a 120v charger that is usually fastened to your boat so that all you have to do when done using your boat is plug it in. You can get them in however many “banks” you want depending on the amount of batteries you are trying to charge. My advice if you have a single 12v trolling battery and a 12v starting battery is to get a 2 bank charger so that you know your always topped off when you hit the water. I have had good luck with the Minnkota digital on-board chargers. I like that they have separate indicator lights for each bank to know what state of charge they are at.
You seem to be confused as well… check the link and you will learn what an onboard alternator charger is. It charges the trolling motor batteries using the outboard alternator when the starting battery is fully charged..
https://minnkotamotors.johnsonoutdoors.com/battery-chargers/board-alternator?id=13891
Ya I did not realize that was another add on onboard charging option.
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