Pontoon Boat & Deck Boat Forum

I have a 24 volt system for my Minn Kota trolling motor. The boat is being docked with no electric. What is the best way to charge the batteries? (Boat dealer says not to use a pergo system as the Merc 60 alternator wouldn't support).

(Mottaman53) I have the same issue. I believe that today's Solar Cell power systems might be the solution. Talked to several people and solar has come a long way in both power output and cost.
I just need to research more and come up with a good storage solution on the boat when not using them. My dealer believes it's a viable solution.
Currently I too have a 24 volt trolling motor system and the to 27 group batteries aren't fun to remove take home etc.
I used the trolling motor in conjunction with the engine so that I now get 5 to 7 outings before having to recharge the batteries.
It would be nice to use the trolling motor by itself and would likely save on gas over several years to pay for the solar system.
Your post has reminded me I should starting looking again fishing season getting very close. If anyone has installed a solar system please post opinion and pictures.

Farmers around here use solar systems to run electric fences. The solar panel is set up and clips to the battery/batteries. When they need to move it, they simply break it down.

I'd guess that hooking one up on a pontoon would be a lot simpler than it might first appear.

And you could stow the solar panel when not in use.

Here is one example I know works.

http://www.orschelnfarmhome.com/Orschel ... 12&offset=

Since solar panel wattage is based on around 17V, those 15W solar panels are going to put out less than 1A of current. For 2 12V batteries you will need 2 of those.

Depending on where you are, you will likely get 5 hours equivalent of sun in one day. Therefore, you will be able to replace maybe 5A/per day. If your 100A/hr batteries are discharged 50%, you will need 10 days to completely charge the batteries back up.

Not sure about you, but that would not be good enough for me. You are going to need much bigger solar panels than that and the area to mount them.

Modern solar panels are around 9 watts per square foot so calculate your space accordingly. At least for a pontoon boat, unless you have a hardtop to be able to mount LARGE solar panels, it's not very feasible.

Another thing, If you don't recharge your batteries right away after you discharge them, they will start to sulfate which reduces their capacity/life/ In an ideal world. you want to charge them up completely right after you discharge them.

Nice work on the math part of the possible solution. Do you happen to know how much a 1,000 watt generator puts out in terms of amp hours? Sounds like I may have to use a generator to charge and a solar panel to maintain?

Mottaman53 wrote:Nice work on the math part of the possible solution. Do you happen to know how much a 1,000 watt generator puts out in terms of amp hours? Sounds like I may have to use a generator to charge and a solar panel to maintain?

Depends on the generator and if it's an inverter type or not. Non inverter type typically only put out a few amps of DC. A lot of generators have no DC output. You would be better off having the generator power a battery charger.

My 3000W Yamaha generator only puts out 12A @ 12Vdc. Of course you have 2 batteries which makes you have to charge and then swap.

The unit I've been looking at are approx 28" X 24" or little larger 80 to 100 watt low light units.
I would need 2 unit with a dual 12/24 controller. The total cost would probably run between $450 to $600.
Haven't research the number yet but told by sellers it's a viable solution and I know RV's make use of them.
Anyway I've been told I need at least two 80 watt unit to charge two 27 group batteries effectively.
I'd likely shoot for two 120 watt units, there a lot of stuff on Ebay.
I could leave the panels laying on table top or even floor when charging,
but my concern if finding a good way to slide into storage out of the way when using the boat.
Need to give that a lot of thought before jumping into.
Dealer simply said no problem but never lay out how he would suggest doing it.
In fact solar was the dealers suggestion and I did express concern over recharge time. However the more I dig into it the more I see the possibilities.
I'm kind of laid back on the idea until I research more, and because if and when I make the investment I better have a good working plan and ready to act.
However I've been leaning towards solar just not ready to make the leap and be nice to hear of someone who has successfully..

Something Like this might work.
http://www.ebay.com/itm/120Watts-Portab ... 4875f4fa8a

at the lake I charge my 24v system troll mt 70lbs thrust thru a minn kota on board charger using my Yammy 1000 gen.
In fact I am going up to the lake tommorow for a week or so

A generator would be a nice option, but I know the marina where I keep the boat won't allow it if unattended, and may not allow it at all.
Do you charge batteries while using trolling motor too?
What's your charging procedure?

Has anyone tried using the DC Alternator on board charger? It supposedly uses the engine alternator to charge the batteries.

Ddancers wrote:A generator would be a nice option, but I know the marina where I keep the boat won't allow it if unattended, and may not allow it at all.
Do you charge batteries while using trolling motor too?
What's your charging procedure?

.
I do it while using the gen to watch tv in camper dual purpose.

killerkernrich wrote:

Ddancers wrote:A generator would be a nice option, but I know the marina where I keep the boat won't allow it if unattended, and may not allow it at all.
Do you charge batteries while using trolling motor too?
What's your charging procedure?

.
I do it while using the gen to watch tv in camper dual purpose.

You may find this useful, but other than just finding it on the web I can't speak for the product:

The Trollbridge24® Combiner allows you to charge your 24 volt trolling motor battery from the 12 volt alternator on your main engine or trailer hook-up. It works by automatically putting two 12 volt batteries in series when you need to run the trolling motor and in parallel for charging. It is bi-directional so when not trolling, the trolling booster battery backs up your starting or house battery.

The Trollbridge24 is suitable for installations with alternators up to 100 amps and 24 volt trolling motors up to 85 amps.

They also offer a 36 volt version that grouser may find useful: Trollbridge36

12 TO 36 VOLT BATTERY CHARGER/COMBINER

I did look into the alternator setup for charging, but my dealer expressed if I do and alternator failed for any reason warrantee would not cover it. In my case that's not something they wouldn't notice because it's a complete service arrangement I have. I'm going to look more into the generator digital converters certainly would be easier. I like the solar route but the panel are large and might not be that easy to deal with. (killerkernrich's) alternative is interesting, I'm just not sure I'll gain much additional motor run time unless I can run the generator while using the trolling motor.

Harbor Freight has a 3 panel 45 watt solar kit for about $190.00. It comes with a controller and is designed to charge 12 volt storage batteries. It might be the solution you're looking for

HarryO wrote:Harbor Freight has a 3 panel 45 watt solar kit for about $190.00. It comes with a controller and is designed to charge 12 volt storage batteries. It might be the solution you're looking for

Thanks I'll check it out too!
Smaller may end up being better.