How can I charge trolling motor batts when no power is available?

[panfried]

I am heading to Canada this summer to do some fishing. I have been there several times before but not with my own boat. Always used rentals. There is no power on the island which i will be staying. I have heard about solar panels to mount on your boat and i have heard about tying my trolling batteries in with my main battery and letting it charge off the motor. Are there any other ways? Or are one of these methods the way to go? Obviously a generator would help but i don't have one and i am not looking to spend a lot of money on this. It is not like i am going to use it alot. Only when i go to canada. Thanks for any help.

[nytelyter]

if you can charge off of main batteries thats what i would do. you would need a pretty good sized solar set up to sufficiently charge your deep cycles imo at least a 45 watt plug and play type and those start at about 499 and a good quiet honda generator would be about the same or a bit more. good luck fishing. ... paul

[Gus]

I would rent a small quiet honda generator to bring with you. Agree with the previous poster that solar isn't going to do much for you unless you get a pretty big pannel. Even then they only charge during the daylight, which is when you'll be out fishing. I don't know what is all involved with hooking things up to charge off the main motor, but my opinion is you'd have to do a lot of driving with the main motor to charge the batteries depleated from a trolling motor.

[pengy]

What I do that works great is to have a set of "jumper cables" that I put on between my starting battery and the trolling battery. I'll hook these up when I leave the dock in the morning or when we go on a "run" to a different fishing spot. When I get to where I am going I'll take the cables off (unless I have a "senior moment" and forget) so that my starting battery does not get discharged. Usually a 15 to 20 minute run at full speed will charge up the trolling battery to the point where I have never run out of "juice". Made a short set of jumpers out of #8 cable and alligator clips on each end. (Leave them in the battery compartment.)

[Hemlock]

Pengy, standard jumper cables from main battery to trolling motor batteries will charge without damage?

We spend the summer on an island with no power, and I'd like to be able to charge trolling motor batts while running. What's the difference between this, and more expensive on board chargers?

[18 inch Crappie]

You need to charge them off the main motor when it is running. They make a isolator that lets you charge your main battery and a 2nd battery at the same time. They use these for RV's all the time. They might make one for 3 batteries also but you would have to check. Solor maybe nice but if there is no sun then what?

[Ears]

Check out the Stay N Charge products. I have one installed on my truck that charges the battries in my fish house while I tow, and I beleive they have a product that charges deep cycle off of your boat motor.

[john.wells]

make sure you use a reliable product designed for using your outboard charging system, such as what has been mentioned. Your "alternator" on most outboards is little more than a small charging coil under the flywheel that delivers an A/C pulse that is then rectified to D/C current and will not produce the "volume" of charge needed for deeply discharged batteries. The excess amount of charge needed can fry your rectifier. This can even happen with just your starting battery. It happened to me. MinnKota also makes a product for your trolling motor batteries as well. I use it now, and it works well.

[marine_man]

What HP motor are you running? If it's smaller than a 115 or perhaps a 90 you're going to have to find some other method... most of the alternators on the smaller motors are exactly how John Wells described it and don't put out a lot of amps...

marine_man

[kunk]

What I did with my boat was order the optional charging package with the motor. This gives my 55hp Suzuki the capability to charge like the larger motors. I also had a switch and the connections installed lets me choose between batt1, batt2, or both. This let's me charge the trolling battery without extra cables. I was anticipating your kind of situation. You do have to do a little running to charge, but I've had the setup to 11 years and it hasn't failed me yet.

[panfried]

I have a 115hp merc 2 stroke. My trollling motor is a 24 volt so i have 2 batts to run that and 1 batt for statring. I have a minnkota 3 bank on board charger also but that will only work with a generator obviously. I can go quite a while when my trolling motor batts are fully charged during moderate usage. I plan on only using the trolling motor if i have to. I have had good luck in the past drifting. But you cant't always count on the wind. I really think that i will probably only have to charge the batts one time during the trip (6 days) but then again you never know. I like the sounds of that charging package "Kunk" what do you think that would cost and or do i need it with the size motor that i have?? Thanks for all the info everyone it's much appreciated.

[katoguy]

There are several isolators which act as interlink between your alternator and trolling motor batteries. After your alternator tops off your crank battery, it then spills over and charges your trolling motor batteries.

Good in theory? Yes.

Real life? Not really, unless you have a high amp alternator and are running a couple hours with your outboard. A 20 minute jog across the lake will really do nothing.

Your best bet is a spare set of batteries, a generator, or an anchor.

[marine_man]

I agree with Katoguy.. you'd have to run quite a bit at wide open to charge your batteries..

Since Mercury doesn't make the 2 stroke 115 anymore I haven't had much luck finding out how big of an alternator it's got, but if I recall it's not real big.

Jim Payne at Stay N Charge could probably tell you if your alternator is sufficient... but I think you're not going to have enough amps to do it.

marine_man

[chak]

According, to Mercury's web site the 115 Optimax has a 60 AMP belt driven alternator. That would be big enough I'd think.

[Big Roy]

How much power do you need? If your looking to run t.v.s, DVD players, lights, and microwaves then you need to rent a generator. If you charge off the boat motor you will only put a "surface charge" into the batteries and they might not last as long as you need. I have a 75hp merc on my Warrior and I have a plug that will let me charge the deep cycles. I have been on remote trips and used this method and the above posters are correct. You need to run the motor along time to charge the batteries enough.

[panfried]

Sounds like I am going to have to find me a generator i guess. Thanks for all the great info guys.

[FullTilt]

If all else fails get a couple good size drift socks and hang'em off the front to slow your back troll. I did this for a few years when camping on Rainy Lake before I got a kicker.

Last spring Cabelas had a deal on drift socks for $19.95, I'd bet they'll do it again this year.

[marine_man]

Quote:

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According, to Mercury's web site the 115 Optimax has a 60 AMP belt driven alternator. That would be big enough I'd think.

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If panfried had had an optimax that'd be great plenty, but I think he's just got a straight two stroke 115, non optimax (the 115 optimax has only been out for a year or two)...

Any fuel injected (4 stroke), or direct injected (2 stroke) motor would have a alternator that would put out enough amps to charge a battery as they require a lot of power to run the injectors, electronics, etc... but a straight 2 stroke under 150 hp or so does not have enough...

marine_man