Trolling motor for auxiliary propulsion
All, Will any M17 owner who has used a trolling motor as auxiliary propulsion for leaving and approaching the dock, and for short term auxiliary propulsion when winds are light, share what you may have learned from the experience? I have a 6hp Tohatsu SailPro. It drives the boat at hull speed in benign conditions with very little throttle (perhaps quarter throttle). it sips fuel. It has a 6 amp alternator that is advertised as capability for recharging batteries. Fact is, the alternator is inadequate for battery charging. We will be cruising with a 50 quart Dometic refrigerator this year, and as a result we’ll be taking a 1000EUi Honda generator and a Noco Genius 26000 (26 amp capability…@14VDC that’s 364W) along to charge the 200AH of deep cycle batteries to keep them near topped up from day to day. Today it occurred to me that if my 45 pound thrust 12V trolling motor will push the boat at a reasonable speed when needed, why not leave the Tohatsu at home? Here’s my thinking… - The outboard uses about a half gallon an hour at 6K RPM…about 5 knots under good conditions. - The generator’s 0.6 gallon tank will run the generator at full load for 7 hours. - Useful energy in the batteries is about 40 percent of capacity to avoid discharge below 50 percent…which is about 80AH. - The battery charger will provide up to 26A when bulk charging the battery if it is significantly discharged. - The trolling motor will draw 40A if run at position 5 (maximum speed), 32A at position 4, and about 24A on position 3. - The Dometic draws about 3A when running to maintain temperature, after cooled down, and it’s duty cycle is likely to be about 40-50 percent of the time while cruising in summer in the Gulf. - The Honda generator is quieter than the Tohatsu. - The outboard is a heavy load on the transom when not in use. - Solar panels are not mounted and are stored when underway. - On days when the wind is unreliable, on the trolling motor we can move about 20 miles (assume 3.5 knots) in 6 hours. If we run the generator long enough to bulk re-charge the batteries for their overnight use, about an hour, before getting underway, then the charger should be able to complete the absorption phase of charging during the six hours of re-positioning (is the assumption that the charger will provide 20A to the trolling motor while charging the battery a good one?) And the overall effect will be that I will use about a third of the fuel using the generator and charger and trolling motor in this fashion, rather than the Tohatsu. And be able to keep the batteries charged efficiently without running the generator for extended time at anchorage on days that we move to a new location (solar will be used if at anchor all day), and be able to leave that heavy outboard off the transom. Thanks for any comments on the feasibility of doing this… Will
Will, Good thoughts and logic. I have 24V 100AH AGM in my boat and a 70 pound thrust motor. It is great for lake and light bay sailing. But when adverse wind and tidal currents conspire, it is inadequate to make a long trek back to the dock on San Francisco Bay and I need the energy density of gasoline. Bill M-17 Robbin Windsor, CA -----Original Message----- From: montgomery_boats [mailto:montgomery_boats-bounces@mailman.xmission.com] On Behalf Of Wilson Frye Sent: Sunday, March 5, 2017 5:22 PM To: For and about Montgomery Sailboats Subject: M_Boats: Trolling motor for auxiliary propulsion All, Will any M17 owner who has used a trolling motor as auxiliary propulsion for leaving and approaching the dock, and for short term auxiliary propulsion when winds are light, share what you may have learned from the experience? I have a 6hp Tohatsu SailPro. It drives the boat at hull speed in benign conditions with very little throttle (perhaps quarter throttle). it sips fuel. It has a 6 amp alternator that is advertised as capability for recharging batteries. Fact is, the alternator is inadequate for battery charging. We will be cruising with a 50 quart Dometic refrigerator this year, and as a result we’ll be taking a 1000EUi Honda generator and a Noco Genius 26000 (26 amp capability…@14VDC that’s 364W) along to charge the 200AH of deep cycle batteries to keep them near topped up from day to day. Today it occurred to me that if my 45 pound thrust 12V trolling motor will push the boat at a reasonable speed when needed, why not leave the Tohatsu at home? Here’s my thinking… - The outboard uses about a half gallon an hour at 6K RPM…about 5 knots under good conditions. - The generator’s 0.6 gallon tank will run the generator at full load for 7 hours. - Useful energy in the batteries is about 40 percent of capacity to avoid discharge below 50 percent…which is about 80AH. - The battery charger will provide up to 26A when bulk charging the battery if it is significantly discharged. - The trolling motor will draw 40A if run at position 5 (maximum speed), 32A at position 4, and about 24A on position 3. - The Dometic draws about 3A when running to maintain temperature, after cooled down, and it’s duty cycle is likely to be about 40-50 percent of the time while cruising in summer in the Gulf. - The Honda generator is quieter than the Tohatsu. - The outboard is a heavy load on the transom when not in use. - Solar panels are not mounted and are stored when underway. - On days when the wind is unreliable, on the trolling motor we can move about 20 miles (assume 3.5 knots) in 6 hours. If we run the generator long enough to bulk re-charge the batteries for their overnight use, about an hour, before getting underway, then the charger should be able to complete the absorption phase of charging during the six hours of re-positioning (is the assumption that the charger will provide 20A to the trolling motor while charging the battery a good one?) And the overall effect will be that I will use about a third of the fuel using the generator and charger and trolling motor in this fashion, rather than the Tohatsu. And be able to keep the batteries charged efficiently without running the generator for extended time at anchorage on days that we move to a new location (solar will be used if at anchor all day), and be able to leave that heavy outboard off the transom. Thanks for any comments on the feasibility of doing this… Will
Thanks, Bill.
On Mar 5, 2017, at 7:42 PM, Bill Dixon <bill@miralee.com> wrote:
Will,
Good thoughts and logic. I have 24V 100AH AGM in my boat and a 70 pound thrust motor. It is great for lake and light bay sailing. But when adverse wind and tidal currents conspire, it is inadequate to make a long trek back to the dock on San Francisco Bay and I need the energy density of gasoline.
Bill M-17 Robbin Windsor, CA
-----Original Message----- From: montgomery_boats [mailto:montgomery_boats-bounces@mailman.xmission.com] On Behalf Of Wilson Frye Sent: Sunday, March 5, 2017 5:22 PM To: For and about Montgomery Sailboats Subject: M_Boats: Trolling motor for auxiliary propulsion
All,
Will any M17 owner who has used a trolling motor as auxiliary propulsion for leaving and approaching the dock, and for short term auxiliary propulsion when winds are light, share what you may have learned from the experience?
I have a 6hp Tohatsu SailPro. It drives the boat at hull speed in benign conditions with very little throttle (perhaps quarter throttle). it sips fuel. It has a 6 amp alternator that is advertised as capability for recharging batteries.
Fact is, the alternator is inadequate for battery charging. We will be cruising with a 50 quart Dometic refrigerator this year, and as a result we’ll be taking a 1000EUi Honda generator and a Noco Genius 26000 (26 amp capability…@14VDC that’s 364W) along to charge the 200AH of deep cycle batteries to keep them near topped up from day to day.
Today it occurred to me that if my 45 pound thrust 12V trolling motor will push the boat at a reasonable speed when needed, why not leave the Tohatsu at home?
Here’s my thinking… - The outboard uses about a half gallon an hour at 6K RPM…about 5 knots under good conditions. - The generator’s 0.6 gallon tank will run the generator at full load for 7 hours. - Useful energy in the batteries is about 40 percent of capacity to avoid discharge below 50 percent…which is about 80AH. - The battery charger will provide up to 26A when bulk charging the battery if it is significantly discharged. - The trolling motor will draw 40A if run at position 5 (maximum speed), 32A at position 4, and about 24A on position 3. - The Dometic draws about 3A when running to maintain temperature, after cooled down, and it’s duty cycle is likely to be about 40-50 percent of the time while cruising in summer in the Gulf. - The Honda generator is quieter than the Tohatsu. - The outboard is a heavy load on the transom when not in use. - Solar panels are not mounted and are stored when underway. - On days when the wind is unreliable, on the trolling motor we can move about 20 miles (assume 3.5 knots) in 6 hours. If we run the generator long enough to bulk re-charge the batteries for their overnight use, about an hour, before getting underway, then the charger should be able to complete the absorption phase of charging during the six hours of re-positioning (is the assumption that the charger will provide 20A to the trolling motor while charging the battery a good one?)
And the overall effect will be that I will use about a third of the fuel using the generator and charger and trolling motor in this fashion, rather than the Tohatsu. And be able to keep the batteries charged efficiently without running the generator for extended time at anchorage on days that we move to a new location (solar will be used if at anchor all day), and be able to leave that heavy outboard off the transom.
Thanks for any comments on the feasibility of doing this…
Will
Interesting idea... I'd say you are going to be all set up to test it, given that you are intending the generator, the fridge, and the charger & large battery bank in any case, and it sounds like you already have the trolling motor too? So I'd say give it a test before a big cruise and see if/how it works. Worst case I think would be if you have to motor for a long time. Test out whether the genny (via the charger & batteries) will run the motor at "high enough" thrust for hours if necessary (fridge off, since you are testing "emergency" propulsion scenario, all power to propulsion system). And, is the motor rated to run for hours at "high enough" thrust? In theory, from your numbers below, you could use position 3 constantly (how fast does that move you?), but with actual efficiency losses in the system (10-20% from generator to motor via charger & batteries) that might be on the edge...try it and see... If you have a clamp-type DC ammeter, then you can take direct readings on your DC cables with everything running - how much current out of the charger to batteries, how much from batteries to trolling motor, are you breaking even, getting a bit into the batteries, or still drawing down batteries. Solar electric panels that would fit on and stow in your boat are pretty much useless for electric propulsion and/or refrigeration needs. Unless you are deploying a large raft panels all around your boat when at anchor (and somehow stowing them when underway) and it's sunny all day every day. I would say the one issue is, you are probably underestimating the power usage of the fridge. If it is the Dometic CF-50 or anything similar, with average power usage rating of 45W (at 70 deg. F steady temp, so if your average temp is higher, it will use more, or if you want to keep it colder than whatever their test temperature is), then at 50% duty cycle (likely in practice, conservative estimate at worst) that's 540WH/day which at 12V nominal is 45AH/day, meaning a couple hours a day running the genny (at full 26A output, with a 10%+ loss via charger & batteries) just to support the fridge. Let us know how the testing goes...:-) The SailPro 6 is massive overkill for an M17, as you have noticed (hull speed at 1/4 throttle!...and 60+ lbs. on the stern...and needs high RPMs to put out much charging current). A lightly used one came with my M17, and I sold it for about 1/3 of what I paid for the whole boat-motor-trailer rig (a nice leveraging of surplus resources :-). The comment about energy density of gasoline is relevant...if you weren't already planning on all that other gear (fridge, genny, & big battery bank) then a Honda 2.3 would be way more efficient... :-) cheers, John S. On 03/05/2017 05:22 PM, Wilson Frye wrote:
All,
Will any M17 owner who has used a trolling motor as auxiliary propulsion for leaving and approaching the dock, and for short term auxiliary propulsion when winds are light, share what you may have learned from the experience?
I have a 6hp Tohatsu SailPro. It drives the boat at hull speed in benign conditions with very little throttle (perhaps quarter throttle). it sips fuel. It has a 6 amp alternator that is advertised as capability for recharging batteries.
Fact is, the alternator is inadequate for battery charging. We will be cruising with a 50 quart Dometic refrigerator this year, and as a result we’ll be taking a 1000EUi Honda generator and a Noco Genius 26000 (26 amp capability…@14VDC that’s 364W) along to charge the 200AH of deep cycle batteries to keep them near topped up from day to day.
Today it occurred to me that if my 45 pound thrust 12V trolling motor will push the boat at a reasonable speed when needed, why not leave the Tohatsu at home?
Here’s my thinking… - The outboard uses about a half gallon an hour at 6K RPM…about 5 knots under good conditions. - The generator’s 0.6 gallon tank will run the generator at full load for 7 hours. - Useful energy in the batteries is about 40 percent of capacity to avoid discharge below 50 percent…which is about 80AH. - The battery charger will provide up to 26A when bulk charging the battery if it is significantly discharged. - The trolling motor will draw 40A if run at position 5 (maximum speed), 32A at position 4, and about 24A on position 3. - The Dometic draws about 3A when running to maintain temperature, after cooled down, and it’s duty cycle is likely to be about 40-50 percent of the time while cruising in summer in the Gulf. - The Honda generator is quieter than the Tohatsu. - The outboard is a heavy load on the transom when not in use. - Solar panels are not mounted and are stored when underway. - On days when the wind is unreliable, on the trolling motor we can move about 20 miles (assume 3.5 knots) in 6 hours. If we run the generator long enough to bulk re-charge the batteries for their overnight use, about an hour, before getting underway, then the charger should be able to complete the absorption phase of charging during the six hours of re-positioning (is the assumption that the charger will provide 20A to the trolling motor while charging the battery a good one?)
And the overall effect will be that I will use about a third of the fuel using the generator and charger and trolling motor in this fashion, rather than the Tohatsu. And be able to keep the batteries charged efficiently without running the generator for extended time at anchorage on days that we move to a new location (solar will be used if at anchor all day), and be able to leave that heavy outboard off the transom.
Thanks for any comments on the feasibility of doing this…
Will
-- John Schinnerer - M.A., Whole Systems Design -------------------------------------------- - Eco-Living - Whole Systems Design Services People - Place - Learning - Integration john@eco-living.net - 510.982.1334 http://eco-living.net http://sociocracyconsulting.com
I used a trolling motor for an auxiliary on my Catalina 22 for several years. It worked extremely well for docking, anchoring, etc. but even with a large 24v battery bank it never had the range to cover long open water distances. I think you won't have enough charging power with that setup to run the motor continuously even on low speed, to do so you would need an impractically large generator and charger to fit on your boat. Personally, I would be comfortable with that as long as I had sails for all conditions (e.g. storm sails, and a nylon drifter). If you plan on motoring on lower motor settings, which saves a lot of electricity, you may want to consider a digitally controlled electric trolling motor with continuously variable speed. These are far more efficient at low speeds, because they don't waste power through a hot resistor to run at lower speeds. Also, since they have variable speed, you will find some (probably very slow) speed where you can maintain stable voltage charging with the generator you have. Tyler ----- Original Message ----- From: "Wilson Frye" <fryewe@mac.com> To: "For and about Montgomery Sailboats" <montgomery_boats@mailman.xmission.com> Sent: Sunday, March 5, 2017 5:22:21 PM Subject: M_Boats: Trolling motor for auxiliary propulsion All, Will any M17 owner who has used a trolling motor as auxiliary propulsion for leaving and approaching the dock, and for short term auxiliary propulsion when winds are light, share what you may have learned from the experience? I have a 6hp Tohatsu SailPro. It drives the boat at hull speed in benign conditions with very little throttle (perhaps quarter throttle). it sips fuel. It has a 6 amp alternator that is advertised as capability for recharging batteries. Fact is, the alternator is inadequate for battery charging. We will be cruising with a 50 quart Dometic refrigerator this year, and as a result we’ll be taking a 1000EUi Honda generator and a Noco Genius 26000 (26 amp capability…@14VDC that’s 364W) along to charge the 200AH of deep cycle batteries to keep them near topped up from day to day. Today it occurred to me that if my 45 pound thrust 12V trolling motor will push the boat at a reasonable speed when needed, why not leave the Tohatsu at home? Here’s my thinking… - The outboard uses about a half gallon an hour at 6K RPM…about 5 knots under good conditions. - The generator’s 0.6 gallon tank will run the generator at full load for 7 hours. - Useful energy in the batteries is about 40 percent of capacity to avoid discharge below 50 percent…which is about 80AH. - The battery charger will provide up to 26A when bulk charging the battery if it is significantly discharged. - The trolling motor will draw 40A if run at position 5 (maximum speed), 32A at position 4, and about 24A on position 3. - The Dometic draws about 3A when running to maintain temperature, after cooled down, and it’s duty cycle is likely to be about 40-50 percent of the time while cruising in summer in the Gulf. - The Honda generator is quieter than the Tohatsu. - The outboard is a heavy load on the transom when not in use. - Solar panels are not mounted and are stored when underway. - On days when the wind is unreliable, on the trolling motor we can move about 20 miles (assume 3.5 knots) in 6 hours. If we run the generator long enough to bulk re-charge the batteries for their overnight use, about an hour, before getting underway, then the charger should be able to complete the absorption phase of charging during the six hours of re-positioning (is the assumption that the charger will provide 20A to the trolling motor while charging the battery a good one?) And the overall effect will be that I will use about a third of the fuel using the generator and charger and trolling motor in this fashion, rather than the Tohatsu. And be able to keep the batteries charged efficiently without running the generator for extended time at anchorage on days that we move to a new location (solar will be used if at anchor all day), and be able to leave that heavy outboard off the transom. Thanks for any comments on the feasibility of doing this… Will
Thanks for your comments. I'll be trying my ideas out this coming weekend in and around St. George's Sound. I'll evaluate the need for a motor with digital speed controls after this weekend's results. I'm using "current inventory" for this initial run. I'll post my evaluation of the weekend next week. Will S/V Puck's Dream Sent from my iPhone
On Mar 5, 2017, at 10:53 PM, casioqv@usermail.com wrote:
I used a trolling motor for an auxiliary on my Catalina 22 for several years. It worked extremely well for docking, anchoring, etc. but even with a large 24v battery bank it never had the range to cover long open water distances.
I think you won't have enough charging power with that setup to run the motor continuously even on low speed, to do so you would need an impractically large generator and charger to fit on your boat. Personally, I would be comfortable with that as long as I had sails for all conditions (e.g. storm sails, and a nylon drifter).
If you plan on motoring on lower motor settings, which saves a lot of electricity, you may want to consider a digitally controlled electric trolling motor with continuously variable speed. These are far more efficient at low speeds, because they don't waste power through a hot resistor to run at lower speeds. Also, since they have variable speed, you will find some (probably very slow) speed where you can maintain stable voltage charging with the generator you have.
Tyler
----- Original Message ----- From: "Wilson Frye" <fryewe@mac.com> To: "For and about Montgomery Sailboats" <montgomery_boats@mailman.xmission.com> Sent: Sunday, March 5, 2017 5:22:21 PM Subject: M_Boats: Trolling motor for auxiliary propulsion
All,
Will any M17 owner who has used a trolling motor as auxiliary propulsion for leaving and approaching the dock, and for short term auxiliary propulsion when winds are light, share what you may have learned from the experience?
I have a 6hp Tohatsu SailPro. It drives the boat at hull speed in benign conditions with very little throttle (perhaps quarter throttle). it sips fuel. It has a 6 amp alternator that is advertised as capability for recharging batteries.
Fact is, the alternator is inadequate for battery charging. We will be cruising with a 50 quart Dometic refrigerator this year, and as a result we’ll be taking a 1000EUi Honda generator and a Noco Genius 26000 (26 amp capability…@14VDC that’s 364W) along to charge the 200AH of deep cycle batteries to keep them near topped up from day to day.
Today it occurred to me that if my 45 pound thrust 12V trolling motor will push the boat at a reasonable speed when needed, why not leave the Tohatsu at home?
Here’s my thinking… - The outboard uses about a half gallon an hour at 6K RPM…about 5 knots under good conditions. - The generator’s 0.6 gallon tank will run the generator at full load for 7 hours. - Useful energy in the batteries is about 40 percent of capacity to avoid discharge below 50 percent…which is about 80AH. - The battery charger will provide up to 26A when bulk charging the battery if it is significantly discharged. - The trolling motor will draw 40A if run at position 5 (maximum speed), 32A at position 4, and about 24A on position 3. - The Dometic draws about 3A when running to maintain temperature, after cooled down, and it’s duty cycle is likely to be about 40-50 percent of the time while cruising in summer in the Gulf. - The Honda generator is quieter than the Tohatsu. - The outboard is a heavy load on the transom when not in use. - Solar panels are not mounted and are stored when underway. - On days when the wind is unreliable, on the trolling motor we can move about 20 miles (assume 3.5 knots) in 6 hours. If we run the generator long enough to bulk re-charge the batteries for their overnight use, about an hour, before getting underway, then the charger should be able to complete the absorption phase of charging during the six hours of re-positioning (is the assumption that the charger will provide 20A to the trolling motor while charging the battery a good one?)
And the overall effect will be that I will use about a third of the fuel using the generator and charger and trolling motor in this fashion, rather than the Tohatsu. And be able to keep the batteries charged efficiently without running the generator for extended time at anchorage on days that we move to a new location (solar will be used if at anchor all day), and be able to leave that heavy outboard off the transom.
Thanks for any comments on the feasibility of doing this…
Will
If you are experimenting to see if the generator/charger can keep up with the motor, try leaving a voltmeter connected to the battery. The voltage will stay stable or rise slowly if the generator can keep up, but will slowly fall if it cannot. It should stay at least above 12.0 volts, ideally higher. The charger overheating could also be a concern. Tyler ----- Original Message ----- From: "Wilson Frye" <fryewe@mac.com> To: "For and about Montgomery Sailboats" <montgomery_boats@mailman.xmission.com> Sent: Monday, March 6, 2017 8:04:29 AM Subject: Re: M_Boats: Trolling motor for auxiliary propulsion Thanks for your comments. I'll be trying my ideas out this coming weekend in and around St. George's Sound. I'll evaluate the need for a motor with digital speed controls after this weekend's results. I'm using "current inventory" for this initial run. I'll post my evaluation of the weekend next week. Will S/V Puck's Dream Sent from my iPhone
On Mar 5, 2017, at 10:53 PM, casioqv@usermail.com wrote:
I used a trolling motor for an auxiliary on my Catalina 22 for several years. It worked extremely well for docking, anchoring, etc. but even with a large 24v battery bank it never had the range to cover long open water distances.
I think you won't have enough charging power with that setup to run the motor continuously even on low speed, to do so you would need an impractically large generator and charger to fit on your boat. Personally, I would be comfortable with that as long as I had sails for all conditions (e.g. storm sails, and a nylon drifter).
If you plan on motoring on lower motor settings, which saves a lot of electricity, you may want to consider a digitally controlled electric trolling motor with continuously variable speed. These are far more efficient at low speeds, because they don't waste power through a hot resistor to run at lower speeds. Also, since they have variable speed, you will find some (probably very slow) speed where you can maintain stable voltage charging with the generator you have.
Tyler
----- Original Message ----- From: "Wilson Frye" <fryewe@mac.com> To: "For and about Montgomery Sailboats" <montgomery_boats@mailman.xmission.com> Sent: Sunday, March 5, 2017 5:22:21 PM Subject: M_Boats: Trolling motor for auxiliary propulsion
All,
Will any M17 owner who has used a trolling motor as auxiliary propulsion for leaving and approaching the dock, and for short term auxiliary propulsion when winds are light, share what you may have learned from the experience?
I have a 6hp Tohatsu SailPro. It drives the boat at hull speed in benign conditions with very little throttle (perhaps quarter throttle). it sips fuel. It has a 6 amp alternator that is advertised as capability for recharging batteries.
Fact is, the alternator is inadequate for battery charging. We will be cruising with a 50 quart Dometic refrigerator this year, and as a result we’ll be taking a 1000EUi Honda generator and a Noco Genius 26000 (26 amp capability…@14VDC that’s 364W) along to charge the 200AH of deep cycle batteries to keep them near topped up from day to day.
Today it occurred to me that if my 45 pound thrust 12V trolling motor will push the boat at a reasonable speed when needed, why not leave the Tohatsu at home?
Here’s my thinking… - The outboard uses about a half gallon an hour at 6K RPM…about 5 knots under good conditions. - The generator’s 0.6 gallon tank will run the generator at full load for 7 hours. - Useful energy in the batteries is about 40 percent of capacity to avoid discharge below 50 percent…which is about 80AH. - The battery charger will provide up to 26A when bulk charging the battery if it is significantly discharged. - The trolling motor will draw 40A if run at position 5 (maximum speed), 32A at position 4, and about 24A on position 3. - The Dometic draws about 3A when running to maintain temperature, after cooled down, and it’s duty cycle is likely to be about 40-50 percent of the time while cruising in summer in the Gulf. - The Honda generator is quieter than the Tohatsu. - The outboard is a heavy load on the transom when not in use. - Solar panels are not mounted and are stored when underway. - On days when the wind is unreliable, on the trolling motor we can move about 20 miles (assume 3.5 knots) in 6 hours. If we run the generator long enough to bulk re-charge the batteries for their overnight use, about an hour, before getting underway, then the charger should be able to complete the absorption phase of charging during the six hours of re-positioning (is the assumption that the charger will provide 20A to the trolling motor while charging the battery a good one?)
And the overall effect will be that I will use about a third of the fuel using the generator and charger and trolling motor in this fashion, rather than the Tohatsu. And be able to keep the batteries charged efficiently without running the generator for extended time at anchorage on days that we move to a new location (solar will be used if at anchor all day), and be able to leave that heavy outboard off the transom.
Thanks for any comments on the feasibility of doing this…
Will
Thanks. I'll do that, and will be sure to keep a close watch on the charger. It may not be able to handle 26A continuous duty, but it seems to me that it's designed for relatively (an hour or more?) long bulk charging of large banks. Will Sent from my iPhone
On Mar 6, 2017, at 11:57 AM, casioqv@usermail.com wrote:
If you are experimenting to see if the generator/charger can keep up with the motor, try leaving a voltmeter connected to the battery. The voltage will stay stable or rise slowly if the generator can keep up, but will slowly fall if it cannot. It should stay at least above 12.0 volts, ideally higher. The charger overheating could also be a concern.
Tyler
----- Original Message ----- From: "Wilson Frye" <fryewe@mac.com> To: "For and about Montgomery Sailboats" <montgomery_boats@mailman.xmission.com> Sent: Monday, March 6, 2017 8:04:29 AM Subject: Re: M_Boats: Trolling motor for auxiliary propulsion
Thanks for your comments. I'll be trying my ideas out this coming weekend in and around St. George's Sound.
I'll evaluate the need for a motor with digital speed controls after this weekend's results. I'm using "current inventory" for this initial run.
I'll post my evaluation of the weekend next week.
Will S/V Puck's Dream
Sent from my iPhone
On Mar 5, 2017, at 10:53 PM, casioqv@usermail.com wrote:
I used a trolling motor for an auxiliary on my Catalina 22 for several years. It worked extremely well for docking, anchoring, etc. but even with a large 24v battery bank it never had the range to cover long open water distances.
I think you won't have enough charging power with that setup to run the motor continuously even on low speed, to do so you would need an impractically large generator and charger to fit on your boat. Personally, I would be comfortable with that as long as I had sails for all conditions (e.g. storm sails, and a nylon drifter).
If you plan on motoring on lower motor settings, which saves a lot of electricity, you may want to consider a digitally controlled electric trolling motor with continuously variable speed. These are far more efficient at low speeds, because they don't waste power through a hot resistor to run at lower speeds. Also, since they have variable speed, you will find some (probably very slow) speed where you can maintain stable voltage charging with the generator you have.
Tyler
----- Original Message ----- From: "Wilson Frye" <fryewe@mac.com> To: "For and about Montgomery Sailboats" <montgomery_boats@mailman.xmission.com> Sent: Sunday, March 5, 2017 5:22:21 PM Subject: M_Boats: Trolling motor for auxiliary propulsion
All,
Will any M17 owner who has used a trolling motor as auxiliary propulsion for leaving and approaching the dock, and for short term auxiliary propulsion when winds are light, share what you may have learned from the experience?
I have a 6hp Tohatsu SailPro. It drives the boat at hull speed in benign conditions with very little throttle (perhaps quarter throttle). it sips fuel. It has a 6 amp alternator that is advertised as capability for recharging batteries.
Fact is, the alternator is inadequate for battery charging. We will be cruising with a 50 quart Dometic refrigerator this year, and as a result we’ll be taking a 1000EUi Honda generator and a Noco Genius 26000 (26 amp capability…@14VDC that’s 364W) along to charge the 200AH of deep cycle batteries to keep them near topped up from day to day.
Today it occurred to me that if my 45 pound thrust 12V trolling motor will push the boat at a reasonable speed when needed, why not leave the Tohatsu at home?
Here’s my thinking… - The outboard uses about a half gallon an hour at 6K RPM…about 5 knots under good conditions. - The generator’s 0.6 gallon tank will run the generator at full load for 7 hours. - Useful energy in the batteries is about 40 percent of capacity to avoid discharge below 50 percent…which is about 80AH. - The battery charger will provide up to 26A when bulk charging the battery if it is significantly discharged. - The trolling motor will draw 40A if run at position 5 (maximum speed), 32A at position 4, and about 24A on position 3. - The Dometic draws about 3A when running to maintain temperature, after cooled down, and it’s duty cycle is likely to be about 40-50 percent of the time while cruising in summer in the Gulf. - The Honda generator is quieter than the Tohatsu. - The outboard is a heavy load on the transom when not in use. - Solar panels are not mounted and are stored when underway. - On days when the wind is unreliable, on the trolling motor we can move about 20 miles (assume 3.5 knots) in 6 hours. If we run the generator long enough to bulk re-charge the batteries for their overnight use, about an hour, before getting underway, then the charger should be able to complete the absorption phase of charging during the six hours of re-positioning (is the assumption that the charger will provide 20A to the trolling motor while charging the battery a good one?)
And the overall effect will be that I will use about a third of the fuel using the generator and charger and trolling motor in this fashion, rather than the Tohatsu. And be able to keep the batteries charged efficiently without running the generator for extended time at anchorage on days that we move to a new location (solar will be used if at anchor all day), and be able to leave that heavy outboard off the transom.
Thanks for any comments on the feasibility of doing this…
Will
Forgot to respond to this part... On 03/05/2017 05:22 PM, Wilson Frye wrote: ...
Will any M17 owner who has used a trolling motor as auxiliary propulsion for leaving and approaching the dock, and for short term auxiliary propulsion when winds are light, share what you may have learned from the experience?
Haven't used one on my own M17, but have used them on a Potter 19 and a Venture 17. Both are somewhat lighter overall than the M17 - Potter at ~1200 and Venture at ~900. But the Potter has more windage than an M17, I reckon. Both boats had to be launched at a ramp, then motored several hundred yards under a low bridge to rig up at another dock past the bridge. The channel has a constant current, ~1 kt. at the low end (tide coming in against river outflow) and probably ~2.5 kt. at the high end (tide and river going out). The trolling motors were fine for this. On the return there was motoring back into the basin/dock to de-rig, against the same current and sometimes against some wind for the first part. The trolling motors also did fine with that. They were not fancy trollers - just ordinary old small ones. I think the Venure 17 one was just a 30 or 35 lb. thrust. The Potter might have had a 40-45 lb. thrust. Against max current and some headwind progress could be slow back to the dock, barely a knot or so over ground. So the motor might be running full or near full power, but only for a short time, a few hundred yards or maybe 1/4 mile at most when returning. As long as the battery was charged up, this was all fine. cheers, John S. -- John Schinnerer - M.A., Whole Systems Design -------------------------------------------- - Eco-Living - Whole Systems Design Services People - Place - Learning - Integration john@eco-living.net - 510.982.1334 http://eco-living.net http://sociocracyconsulting.com
Thanks, John. Just the kind of experience I was hoping to get a synopsis of… Will
On Mar 6, 2017, at 2:26 PM, John Schinnerer <john@eco-living.net> wrote:
Forgot to respond to this part...
On 03/05/2017 05:22 PM, Wilson Frye wrote: ...
Will any M17 owner who has used a trolling motor as auxiliary propulsion for leaving and approaching the dock, and for short term auxiliary propulsion when winds are light, share what you may have learned from the experience?
Haven't used one on my own M17, but have used them on a Potter 19 and a Venture 17. Both are somewhat lighter overall than the M17 - Potter at ~1200 and Venture at ~900. But the Potter has more windage than an M17, I reckon.
Both boats had to be launched at a ramp, then motored several hundred yards under a low bridge to rig up at another dock past the bridge. The channel has a constant current, ~1 kt. at the low end (tide coming in against river outflow) and probably ~2.5 kt. at the high end (tide and river going out). The trolling motors were fine for this. On the return there was motoring back into the basin/dock to de-rig, against the same current and sometimes against some wind for the first part. The trolling motors also did fine with that. They were not fancy trollers - just ordinary old small ones. I think the Venure 17 one was just a 30 or 35 lb. thrust. The Potter might have had a 40-45 lb. thrust.
Against max current and some headwind progress could be slow back to the dock, barely a knot or so over ground. So the motor might be running full or near full power, but only for a short time, a few hundred yards or maybe 1/4 mile at most when returning. As long as the battery was charged up, this was all fine.
cheers, John S.
-- John Schinnerer - M.A., Whole Systems Design -------------------------------------------- - Eco-Living - Whole Systems Design Services People - Place - Learning - Integration john@eco-living.net - 510.982.1334 http://eco-living.net http://sociocracyconsulting.com
Glad it is helpful... I'm not sure how the bigger trolling electrics compare with Torqeedo's electrics. I have a little experience with a Torqeedo 1003, which the club also bought as a gas-free auxiliary, mainly for one or two larger boats. It was used some on the Potter 19 and was plenty of power - Torqeedo compares it to a 3hp gas engine. Mostly it is used for one or another of two international folkboats the club has, which for those not familiar is a full keel 4750 lb. displacement boat. Again not as a long-range or intense conditions motoring solution, but for getting on and off a mooring in a fairly tight and flukey-wind location, or for motoring in and out under the bridge and back to the intermediate dock to rig up or down, same as described for the Potter 19 and Venture 17. Definitely enough power for that. And, range is still an issue, for any electric...I don't have enough experience to back, or buck, Torqeedo's claims of range/running time. It does have a high-tech monitor screen which tells you power usage, remaining run time at current usage, etc. etc. so at least in terms of information you've got more than with a regular trolling motor and battery. cheers, John S. On 03/06/2017 05:22 PM, Wilson Frye wrote:
Thanks, John. Just the kind of experience I was hoping to get a synopsis of…
Will
On Mar 6, 2017, at 2:26 PM, John Schinnerer <john@eco-living.net> wrote:
Forgot to respond to this part...
On 03/05/2017 05:22 PM, Wilson Frye wrote: ...
Will any M17 owner who has used a trolling motor as auxiliary propulsion for leaving and approaching the dock, and for short term auxiliary propulsion when winds are light, share what you may have learned from the experience?
Haven't used one on my own M17, but have used them on a Potter 19 and a Venture 17. Both are somewhat lighter overall than the M17 - Potter at ~1200 and Venture at ~900. But the Potter has more windage than an M17, I reckon.
Both boats had to be launched at a ramp, then motored several hundred yards under a low bridge to rig up at another dock past the bridge. The channel has a constant current, ~1 kt. at the low end (tide coming in against river outflow) and probably ~2.5 kt. at the high end (tide and river going out). The trolling motors were fine for this. On the return there was motoring back into the basin/dock to de-rig, against the same current and sometimes against some wind for the first part. The trolling motors also did fine with that. They were not fancy trollers - just ordinary old small ones. I think the Venure 17 one was just a 30 or 35 lb. thrust. The Potter might have had a 40-45 lb. thrust.
Against max current and some headwind progress could be slow back to the dock, barely a knot or so over ground. So the motor might be running full or near full power, but only for a short time, a few hundred yards or maybe 1/4 mile at most when returning. As long as the battery was charged up, this was all fine.
cheers, John S.
-- John Schinnerer - M.A., Whole Systems Design -------------------------------------------- - Eco-Living - Whole Systems Design Services People - Place - Learning - Integration john@eco-living.net - 510.982.1334 http://eco-living.net http://sociocracyconsulting.com
-- John Schinnerer - M.A., Whole Systems Design -------------------------------------------- - Eco-Living - Whole Systems Design Services People - Place - Learning - Integration john@eco-living.net - 510.982.1334 http://eco-living.net http://sociocracyconsulting.com
participants (4)
-
Bill Dixon -
casioqv＠usermail.com -
John Schinnerer -
Wilson Frye