Question about trolling motor performance

[Silvertip]

Re: Question about trolling motor performance

^^^ I do agree with that, and maybe that's what colby was getting at.

Though battery usage wise, it's going to take the same amount of power (AH) creeping along at speed 1 as compared to wide open at speed 5, with an old speed coil TM.

That may be true in an "unloaded" (out of water) situation but placing a load on an electric motor causes current draw to rise dramatically. That draw is not linear as well. Only an ammeter can how what those numbers are.

 

[colbyt]

Re: Question about trolling motor performance

I frequently copy note from articles but I always attribute them even for my personal use. If I can find the link on my drive I will post it and let you read the article.

 

[fishrdan]

Re: Question about trolling motor performance

That may be true in an "unloaded" (out of water) situation but placing a load on an electric motor causes current draw to rise dramatically. That draw is not linear as well. Only an ammeter can how what those numbers are.

Correct, I don't know the exact amp draw as I've never measured it. From experience on the water using speed coil TM's, I would drain a battery at a constant current, whether using speeds 2-3 a lot or speeds 3-4, 40 amp, TM would only go 4-5 hours on a 105AH battery. Same scenerio with a digital TM would yield 10-12 hours of run time.

MK's website says this about speed coil TM's: Power from the battery is fairly constant regardless of the speed setting. Therefore, on speed 1 for example, more power is diverted to the speed coil than is supplied to the motor. This makes the overall motor assembly less efficient (vs. variable speed/Digital Maximizer). Which goes right along with what my experiences have been on the water.

It would be interesting to see the exact amount of current different TM's draw at different speeds and loads...

 

[fishrdan]

Re: Question about trolling motor performance

I frequently copy note from articles but I always attribute them even for my personal use. If I can find the link on my drive I will post it and let you read the article.

Cool, I'd like to see what it says.

 

[colbyt]

Re: Question about trolling motor performance

This article Trolling Motor Performance does not have a graph but it does have a chart and contains the same information more less. I know this page was involved in my choices. It may not be the final page I read. I read several articles while trying to decide which battery would give me the most bang for my buck. As it was the Endura or oars last year, I wanted to go as far as possible with a single battery charge.

If you look at the table speed 5 uses twice the amps as 4 does, gains you .7 MPH, reduces your total run time by a factor of 2-1 and cuts your total travel distance almost in half.

In the real world on a mildly windy day (cross wind) with a 600 pound load and no GPS in the boat the increase in speed between 4 and 5 was not noticeable. When we used the same rig on a creek we never exceeded 3 going upstream (very mild current).

As I think I said above we have not yet tested it on the 14/48 but I expect it to perform as well or better since we sit higher in the water.

Comments on the article are surely appreciated.

 

[ninhalo5]

Re: Question about trolling motor performance

Well, I think there is an issue somewhere, I just noticed the negative post on my battery is now black and prior to hooking up that motor, it was a brand new shiny silver, not only that but I went to charge my battery and the meter on the charger when I hooked it up this time said 95% @ 5V. It charged up to 100% @ 6V.
Being I had no problems with that battery until hooking the TM up to it tells me something is wrong with the motor, so I think I'll take it and the battery back, do an exchange and try it again.

 

[fishrdan]

Re: Question about trolling motor performance

This article Trolling Motor Performance does not have a graph but it does have a chart and contains the same information more less.

Don't take this the wrong way, but this is what I took from the article.

Something about that article and chart is skewed, from the numbers it looks like he had a digital TM. As MK's old Digital Maximizer slogan goes, "Up to 5 times the run time", and that's what the chart looks like, 1.3 hours at full speed and 7.2 hours on speed 1. If speed coil TM's were that efficient, there wouldn't be a need for digital TM's.

Also, he says a 75AH battery will only run his Endura 30 (speed coil) TM for 1.3 hours at top speed (30 amps), but that should be 2.5 hours. And from his numbers:
- running at speed 4 drawing 15.3 amps, should be almost 4.9 hours instead of his 3.2
- running at speed 3 drawing 12.5 amps should be 6 hours instead of his 4.1
- running at speed 2 drawing 9.3 amps should be 8 hours instead or his 6.1
- running at speed 1 drawing 7.2 amps should be 10.4 hours instead of his 8.5

I could see a digital TM behaving like that, even though his numbers are skewed, but not an Endura speed coil TM.

 

[fishrdan]

Re: Question about trolling motor performance

I went to charge my battery and the meter on the charger when I hooked it up this time said 95% @ 5V. It charged up to 100% @ 6V.

5V - 6V? I'm not understanding where 5V and 6V is coming from? Is that a 5 amp and 6 amp charge rate?

 

[ninhalo5]

Re: Question about trolling motor performance

5-6V is all the power the battery now has, so 100% charge is only 1/2 power or 6 volts compaired to the 12 it is supposed to be. The charger is a 15 amp deep cycle marine battery charger, that tells me what the current volts and charge percentage is.

 

[Silvertip]

Re: Question about trolling motor performance

6 volts is a dead 12 volt battery. Period. You cannot have a full charge with a 6 volt reading on a 12 volt battery. 1/2 power on a 12 volt battery is also not 1/2 charge. You have a bad charger or a bad battery. Put the charger on your car battery and see what it says.

 

[ninhalo5]

Re: Question about trolling motor performance

6 volts is a dead 12 volt battery. Period. You cannot have a full charge with a 6 volt reading on a 12 volt battery. 1/2 power on a 12 volt battery is also not 1/2 charge. You have a bad charger or a bad battery. Put the charger on your car battery and see what it says.

I'm pretty sure I have a bad TM that fried my battery. The charger is perfect and the battery was too until the TM was hooked to it. Either way the TM is less than a week old, and the battery has a 1 year replacement, so I should be good on getting both replaced. I'll trade them both in tomorrow and I'll see what happens on the next round, which I won't get to test out for about 2 weeks when I get back from Florida.

 

[fishrdan]

Re: Question about trolling motor performance

WOW, that's some bad luck, battery definitely cooked and the TM....... Must have been the first one Monday morning or the last on Friday afternoon.

 

[ninhalo5]

Re: Question about trolling motor performance

I think I got me a Tuesday model this time. I exchanged the battery and motor and just got it hooked up and in a bucket of water. the first thing I noticed before turning it on was the propeller had more of a drag or jerkiness to it as silver tip mentioned. I turned it on to 1 and it flung water pretty heavily, where on the other motor, setting 5 barely made a splash. Turning it up half way almost looked like I had my Johnson 7.5 in there. Hopefully I have a winning combination now.

Another question I have is about a circuit breaker, I bought one of those 50 amp Minn kota breakers to be on the safe side and it says to hook inline within 6" of the terminal. Well the motor has big connectors and wires for the battery and the breaker has these little 1/8" bolts, how am I supposed to hook this up properly?

Thanks

 

[fishrdan]

Re: Question about trolling motor performance

Some of the small circuit breakers some with a metal tab to connect to the battery and a crimp connector with the correct sized hole.

Like yours, mine didn't come with the correct hardware, so I cut 3/4" off a 1" copper pipe, smashed it flat, drilled holes and tinned it with solder, then dug around in my plethora of electrical stuff and found the correct sized crimp connector. The crimp connector is going to be the hard one to find as most have bigger screw holes.