Trolling motor/Canoe Charging question

Ok so I’m thinking about getting a trolling motor set up for my canoe, the only problem that I have is the charging of the deep cycle battery. Now I don’t live on a lake and where I typically go camping/canoeing is primitive sites, so no electricity. So the only way to charge the battery would be coming from my car. So is it feasible to just hook up jumper cables and charge it that way? How long would it take to recharge doing it this way? Not sure I want to run the car for 4-5 hours every day to charge the battery.

Or the other option I was considering was getting a 25 amp quick charge charger and hook it up through a 1000-2000W power inverter. Going from 12vDC converted to 110AC through the inverter and then back to DC through the charger seems like a big waste of energy (although I’m not an electrical engineer so who knows)

Any thoughts? Or is this just not feasible without a electric hookup?


have a look at the MinnKota …

– Last Updated: Feb-03-10 6:49 PM EST –

...... Traxxis w/maximizer (variable speed) technology in 45 lb. - 12v - 36" ... "maximizer" saves big on batt. usage and gives you greater time endurance on any batt.

have a look at the "2 bank" , 3 stage chargers MK 210P or MK 230P .

I would suggest having 2 marine deep cycle (6 cell) marine batts. (at least 115 AH) . Use one at a time , keep 2nd in spare . You need to keep the batts. on the charger all the time to maintain them , when not in service as in home from a trip (hence the trickle charge maintenance stage) .

You can think of the AH rating as how much fuel (time) you have on a batt. , the larger AH the longer run time , but weight and size goes up with AH also .

If you keep those batts. well charged and maintained , you should have tons of hour usage time with that set up ... like 3 days is not inconcievable !!

You are kidding about using a car to recharge a marine deep cycle batt. , right ??

Which motors have you been looking at ??

Solar panel
If you are not planning to use the battery every day then you can use a solar panel to recharge it. I got a small panel (about 16 x 18 inches) from harbor freight. On a sunny day it will charge the battery back up in a day.

30# trolling motor

– Last Updated: Feb-04-10 7:05 PM EST –

The trolling motor I was thinking of getting was this one

It is a 30# thrust @ 30AMP So if I had a 110AH battery that gives me proximity a little under 4 hours of use at full power (not much time) so if I’m conservative with use and only run it at ½ power (I’m assuming ½ the Amps) that should give me about 8 hours of continuous use.

Now I’m not just going to turn it on and leave it on, I’m going to use it to head to a fishing spot, turn it off and fish, periodically use it to keep the canoe where I want it, and then move on to the next spot. So I’m estimating in a full day of fishing draining 1/3 to maybe ½ of the battery.

Now if it’s an 110AH battery and I drained ½ of it I need to put in 55 AMPs back in to get it to 100% So using a 10Amp charger will take 5.5 hours to get it to full (actually longer if it is a 3 stage charger because it drops the amps down when it gets to 75%) So that is a bit unrealistic for me to run the car for 5-6 hours to power the charger.

Yes I was serious about using jumper cables, most car alternators have an output of 40 AMPs @ 13-14V. The problem is I don’t know how much of the 40 AMPS are going to be available to go through the car battery and then into the Deep Cell Battery. But if 25-30 AMPs are transferring than I could get a charge in 1.5-2 hours (more reasonable).

I thought about using a solar charger, and if I get 2 batteries then this might be an option, using 1 battery while the other is hooked up to the solar charger, but I haven’t done much research on how fast a small solar charger will work, the ones I’ve seen are just to maintain the battery, so if the battery is ½ drained could it get it back in 8 hours of good light? Maybe an hour on the jumper cables and then let the solar charger trickle the rest might be another option.

EDIT- To elaborate on the 40 AMP alternators, that is based at an idle, most cars the alternator run much more amps. For example my Van has a 130 AMP alternator, but you will never get that at an idle, I was told to expect 1/3 of that at an idle (I have no idea if this info is accurate or not) So my 130 Amp alternator at Idle would theoretically be running at 40 amps, again not sure how accurate the 1/3 at idle is, I’m sure that is just a generalization. Maybe I should just pick up an amp meter and find out.

check out the FAQ’s about …

– Last Updated: Feb-05-10 12:42 AM EST –

...... Maximizer technology vs. speed coil technology on that MinnKota link (Traxxis) .

I would never use a speed coil again in my life after experiencing the "huge" difference between the two in terms of batt. power consumption .

What they say about 5x more time on a batt. is pretty much the reality . We know !!

Now if they would just make a 30 lb. motor w/Maximizer , that could be the cat's meow for canoers who just want to go forward not much faster than paddle speed , but 45 lb. isn't too much (especially if you want to run "up" a river current) , and consider you don't have to open it up if you don't want to .

I can also tell ya this , you will fall in love with a variable speed tiller throttle , makes a world of difference .

If you wanted , you could can change the head and tiller around 180 degrees (probably most motors) , a puller instead of a pusher . Shaft lengths can be shortened to customize on most motors also .

And if you can , mount that motor on the center line , either off the stern or bow stem decks (just takes a wee bit of imagination) .

In rocky rivers you might consider "not" locking the shaft tilt function when in forward , could save the day on rock or submerged wood grab .

Also consider that 45 lb. can be used on a Jon boat or similar (an opt.) , really slow but it can be used that way too .

On that link there is also info. about "On Board" chargers (meant to be used on power boats) , but they could probably be run right off an auto Alternator just the same way ??

Best of luck and let us know how it turns out later , ok ... it's all good !!

Maximizer technology
Thanks for the info, but to be honest I’m not sure how much the Maximizer technology would really help me out. If all I was using it for was typical trolling when its on/off on/off etc all day then sure it probably would help a lot. But because I’m also using it for my main propulsion to get around I just don’t see how it will benefit that much. Considering the majority of my AMP usage is going to be used up for travel and if I want to travel at slightly over paddling speed, it is going to take a certain amount of power to do that (amps). So unless speed 2 is too slow and speed 3 is too fast I don’t see much advantage. It’s kind of like a car where a good amount of your fuel consumption is used during acceleration rather then cursing, but in my case I’m mostly cursing. So yes when I move into fishing mode and start using the trolling motor like a trolling motor I would probably save on power, but unfortunately that would be a small% of what I’m using it for.

The ones I looked at where 2-3 times the price of the reg model I was looking at so I’m not sure the extra cost would really work out because I really doubt the way I would be using it I would get 5 times the battery life. But it is something to defiantly look into. I think I will contact them and let them know how I will be using it and how much more battery life I could expect, and then decide if the extra cost is justified.

Although with my lack of charging options anything that prolongs battery life I’m going to have to seriously consider.

Thanks for the info

it worked
Ok so I just got back from my trip, the trolling motor I went with was the bass pro shop one in the link I had (they had it on sale for $79) and I went with a 115AH battery from walmart.

For charging I built my own solar panel from solar cells, and charge controller I bought from ebay. It is a 80W charger that I built into a large folding case to protect it on the trip. The solar charger worked great it kept the battery topped off… when there was sunlight. Unfortunately I had some cloudy days in there, and the battery dropped down to about 50% (12.10V) we where planning a full day fishing trip the next day and with no sun and the battery already low I decided to give the jumper cables a try.

Now I picked up an amp meter so I could monitor how much amps where being transferred, and with a battery@ 50% the cables where transferring 18Amps of power through the cables. It’s interesting to note that the higher the deep cell battery got topped off the lower the amps being transferred was. When the battery was around 80% full it was putting in 14Amps.

I have read a lot about how deep cells like to be charged and they can take higher amps for the bulk of the charge up to 80% or so and then the amps drop off to protect the battery. So not wanting to damage the battery I would pull the battery off the cables and check it often to make sure I didn’t go past the 80%, it worked great I had enough power for our trip and hopefully didn’t damage the battery (only time will tell) but being that I didn’t go past 80% I think I should be fine.

So if anyone is in a similar situation with out charging options, jumper cables can work, you just need to be carful not to over charge to protect the battery.

glad it’s all working out for ya …
… always more than one way to skin a cat . You kept your initial cost down I guess , and that works too .

You feel the motor pushed you around good enough ??

worked great
Yes the 30lb motor worked great, even in heavy wind. I read on another site that going with a motor that is higher then 30lb is just a waste for a canoe.

The difference between 30, 40 50lb etc is virtually the same speed. the problem is that to really get the canoe to move faster you need to get it up on plane, and there isn’t a trolling motor made that has the power to do that.

So if you had a drag race between a 30lb vs a 50lb trolling motor the 50lb would inch ahead, but would drain the battery in 1/2 the time, the slight increase in speed isn’t worth the battery drain.

I had the canoe loaded up with 3 people, fishing gear and in a heavy wind it would move faster then I could paddle it, so I’m totally happy.