Reply
 
Thread Tools Search this Thread
 
Old 30 October 2020, 06:27   #1
Member
 
Country: UK - England
Town: Nottinghamshire
Make: Ranieri 15
Length: 4m +
Engine: Suzuki DF50
Join Date: Jul 2016
Posts: 424
Electric Auxiliary?

I'm thinking of buying a 55lb thrust electric auxiliary as backup motor. My thinking is it would be stored away and only mounted when needed, I'd probably have to extend the cable but connect it directly to the battery.

Are these credible? I'm only after displacement speed but how long/how far is realistic presuming the 110ah battery is fully charged before the main engine fails? Would it be able to overcome a 4 or 5 knot current?

Anyone else done this in preference to a small fixed petrol outboard?

Bonus: I could make a transom bracket and also use it on the kayak.
__________________

__________________
Limecc is offline   Reply With Quote
Old 30 October 2020, 08:53   #2
Member
 
Country: UK - England
Town: Retford
Boat name: Spy-sea-one
Make: Excel 435
Length: 4m +
Engine: Suzuki Outboard/25/4
Join Date: Oct 2011
Posts: 6,336
RIBase
i had one wasn't impressed that was in the river sooner have a 2 hp two smoke OMO
__________________

__________________
jeffstevens763@g is offline   Reply With Quote
Old 30 October 2020, 08:59   #3
Member
 
Last Tango's Avatar
 
Country: UK - Scotland
Town: Denny
Boat name: Hebridean Storm
Make: Coastline
Length: 6m +
Engine: Mariner F150
MMSI: 235107505
Join Date: Mar 2013
Posts: 1,615
Quote:
Originally Posted by Limecc View Post
>>>> Would it be able to overcome a 4 or 5 knot current?<<<<<
No. That's going to take more than 55lb static.
__________________
Last Tango is offline   Reply With Quote
Old 31 October 2020, 04:54   #4
Member
 
Country: UK - England
Town: Waterlooville
Boat name: Tickler
Make: Halmatic P22
Length: 6m +
Engine: Inboard Diesel 140HP
MMSI: 235115642
Join Date: Sep 2015
Posts: 1,205
RIBase
Via Google, 55lb thrust is about 2.5hp. Based on the 1hp per metre of length rule of thumb for auxillary outboards, I don't think it would be sufficient, particularly to achieve 5 or 6 knots.
__________________
GuyC is offline   Reply With Quote
Old 31 October 2020, 05:35   #5
Member
 
spartacus's Avatar
 
Country: UK - Scotland
Town: Aberdeenshire
Boat name: Sula
Make: Ribcraft 4.8m
Length: 4m +
Engine: Tohatsu 60hp + aux
MMSI: 235087213
Join Date: Jun 2007
Posts: 3,998
RIBase
You mention about being able to store it and then deploy it. In my experience you want an auxilliary on the transom ready to fire up. I've seen them attached to brackets in front of consoles, but I wonder if you have to use them in anger, then what?

I've got a Mariner 4hp on my Ribcraft 4.8m. I was looking for a Tohatsu 5hp, partly because they have narrow cowls for the main engine to turn. I think a 5hp can connect to main fuel supply too.

I think all these things will be electric in years to come, but right now my money is on technology that works.
__________________
Is that with or without VAT?
spartacus is offline   Reply With Quote
Old 31 October 2020, 07:49   #6
Member
 
Country: UK - England
Length: 3m +
Join Date: Sep 2008
Posts: 2,624
Presumably one reason for a aux being needed would be loss of electrical power...

Most with petrol aux would have a can of clean fuel to at least let them limp to safety somewhere.

If the batter is flat. The main lump won't start. The radio won't work because the battery is flat. The best use for the electric aux will be on a rope as an anchor.
__________________
ShinyShoe is offline   Reply With Quote
Old 31 October 2020, 16:29   #7
Member
 
Maximus's Avatar
 
Country: UK - England
Town: Wild West
Boat name: No Boat
Make: No Boat
Length: under 3m
Join Date: Jan 2008
Posts: 4,961
Send a message via AIM to Maximus
Quote:
Originally Posted by ShinyShoe View Post
Presumably one reason for a aux being needed would be loss of electrical power...

Most with petrol aux would have a can of clean fuel to at least let them limp to safety somewhere.

If the batter is flat. The main lump won't start. The radio won't work because the battery is flat. The best use for the electric aux will be on a rope as an anchor.

I agree!....why add complexity a problem with a well proven remedy already.
__________________
A clever Man learns by his mistakes..
A Wise Man learns by other people's!

The Road to HELL ..is Paved with "Good inventions!"
Maximus is offline   Reply With Quote
Old 31 October 2020, 19:42   #8
Member
 
Country: UK - England
Town: Nottinghamshire
Make: Ranieri 15
Length: 4m +
Engine: Suzuki DF50
Join Date: Jul 2016
Posts: 424
Quote:
Originally Posted by ShinyShoe View Post
Presumably one reason for a aux being needed would be loss of electrical power...

Most with petrol aux would have a can of clean fuel to at least let them limp to safety somewhere.

If the battery is flat. The main lump won't start. The radio won't work because the battery is flat. The best use for the electric aux will be on a rope as an anchor.
Quote:
Originally Posted by Maximus View Post

I agree!....why add complexity a problem with a well proven remedy already.
Only have a handheld radio and if the loss of electrical power or main engine presumably the battery is fully charged and ready to go. Just attach the crocodile clips directly so you can't get much simpler.

However if the motor isn't up to it then it's a (pun) non-starter. Can't understand why the yachties have them if they are so crap.
__________________
Limecc is offline   Reply With Quote
Old 01 November 2020, 03:41   #9
Member
 
Country: UK - England
Town: Chelmsford
Length: 4m +
Join Date: Jul 2020
Posts: 417
If your battery was still ok you would be sitting there in the tide (assuming there was a tide) with your 55lb thrust motor spinning away getting no where until your battery went flat.

Small electric outboards are not much use if the water is flowing with any sort of power/speed
__________________
smallribber is offline   Reply With Quote
Old 01 November 2020, 05:20   #10
Member
 
Pikey Dave's Avatar
 
Country: UK - England
Town: South Yorks
Boat name: Black Pig
Make: Ribcraft
Length: 5m +
Engine: DF140a
MMSI: 235111389
Join Date: Feb 2008
Posts: 9,998
RIBase
Quote:
Originally Posted by Limecc View Post
Can't understand why the yachties have them if they are so crap.

Iím guessing that theyíre useful for running the tender across to the harbour/pontoon/yacht club from the mooring. Saves having smelly cans of petrol aboard & the battery can be charged up from the yacht engine/solar/wind generator.
__________________
Rule#2: Never argue with an idiot. He'll drag you down to his level & then beat you with experience.
Rule#3: Tha' can't educate pork.
Rule#4:https://www.youtube.com/watch?v=unkIVvjZc9Y
Pikey Dave is offline   Reply With Quote
Old 01 November 2020, 05:38   #11
Member
 
Country: UK - England
Town: Waterlooville
Boat name: Tickler
Make: Halmatic P22
Length: 6m +
Engine: Inboard Diesel 140HP
MMSI: 235115642
Join Date: Sep 2015
Posts: 1,205
RIBase
Quote:
Originally Posted by Limecc View Post
Only have a handheld radio and if the loss of electrical power or main engine presumably the battery is fully charged and ready to go. Just attach the crocodile clips directly so you can't get much simpler.

However if the motor isn't up to it then it's a (pun) non-starter. Can't understand why the yachties have them if they are so crap.
There are quite a few sub 3m tenders that come with a 2.5 hp outboard and as PD says they are just meant for going ashore / getting back to the boat. In this use, the electric equivalents are probably quite a good option - lighter, quieter and less messy than a petrol outboard. There is a price premium for this but I can certainly see the attraction
__________________
GuyC is offline   Reply With Quote
Old 01 November 2020, 08:46   #12
Member
 
Country: UK - England
Town: Somerset
Make: Takacat
Length: 3m +
Join Date: Jun 2018
Posts: 33
Electric outboard( trolling motors) seem to bring out some strong opinions, particularly against! I used a 55lb unit as my backup on my last boat. ( now have small sib, so no longer used).
Mine would push my 15ft cuddly cabin boat (approx 500kg) quitehappily in tidal waters, at about 3/3.5 knots . It was accepted that in a strong tide, it may well struggle, but I thought a small petrol would also. I canít remember its range, but at steady pace, would run 1.5 hours or so on 100ah battery, which I thought was good enough to get to shore, or even back to base, depending on distance and conditions. It is clean, requires almost nil maintenance, is easy to stow, deploy, and use, and is almost silent, making its use in areas of wildlife areas a revelation.
In the end, itís a personal choice, based on where you go boating, potential risk, and running/ maintenance costs.
With a good anchor, and handheld radio, I think it was a viable option in the appropriate environment.
__________________
Old seahorse is offline   Reply With Quote
Old 02 November 2020, 11:46   #13
Member
 
Country: UK - England
Town: Retford
Boat name: Spy-sea-one
Make: Excel 435
Length: 4m +
Engine: Suzuki Outboard/25/4
Join Date: Oct 2011
Posts: 6,336
RIBase
Be aware that a lot of these elec motors are for fresh water use only
__________________
jeffstevens763@g is offline   Reply With Quote
Old 02 November 2020, 14:15   #14
Member
 
Country: UK - England
Town: Somerset
Make: Takacat
Length: 3m +
Join Date: Jun 2018
Posts: 33
Good point Jeff. mine is salt water compatible, with anode, but you do need to check. Also, some come with battery state meter, which allows you to monitor available range. Some makes come with different shaft lengths too.
__________________
Old seahorse is offline   Reply With Quote
Old 02 November 2020, 14:50   #15
Member
 
Country: UK - England
Town: Surrey
Boat name: Fandango
Make: Ballistic
Length: 6m +
Engine: Yamaha 150
MMSI: 232028101
Join Date: Sep 2015
Posts: 132
RIBase
I've got a Torqeedo 1103 - it's designed to push heavy'ish boats along slowly. I didn't get much opportunity to try it out this summer, but on a calm lake it pushes the boat along at 4/5 knots. I found it difficult to steer using the elec outboard, so I'll try using the main engine as a rudder next time. I'm not convinced it has enough power to get home, maybe off the rocks...

I also need a transom aux engine mount to make it easier to use.
__________________
_monkey is online now   Reply With Quote
Old 02 November 2020, 16:26   #16
Member
 
Last Tango's Avatar
 
Country: UK - Scotland
Town: Denny
Boat name: Hebridean Storm
Make: Coastline
Length: 6m +
Engine: Mariner F150
MMSI: 235107505
Join Date: Mar 2013
Posts: 1,615
Quote:
Originally Posted by _monkey View Post
I've got a Torqeedo 1103 - it's designed to push heavy'ish boats along slowly. I didn't get much opportunity to try it out this summer, but on a calm lake it pushes the boat along at 4/5 knots. I found it difficult to steer using the elec outboard, so I'll try using the main engine as a rudder next time. I'm not convinced it has enough power to get home, maybe off the rocks...

I also need a transom aux engine mount to make it easier to use.
My aux is held in the "ahead" position with a stiff stainless spring onto the "A" frame and I steer with the main engine (trimmed well out). It does have a friction screw but I'm yet to find one of those that actually stops the engine turning. Can still move it for close in maneuvers if need be but ideal for shallow water where you don't want to risk an expensive prop...
__________________
Last Tango is offline   Reply With Quote
Old 24 November 2020, 03:45   #17
Member
 
Country: Canada
Town: Comox
Length: 4m +
Join Date: Aug 2017
Posts: 36
Quote:
Originally Posted by _monkey View Post
I've got a Torqeedo 1103 - it's designed to push heavy'ish boats along slowly. I didn't get much opportunity to try it out this summer, but on a calm lake it pushes the boat along at 4/5 knots. I found it difficult to steer using the elec outboard, so I'll try using the main engine as a rudder next time. I'm not convinced it has enough power to get home, maybe off the rocks...

I also need a transom aux engine mount to make it easier to use.

I have a 25 foot alum Rhib with a 200 Etec. I enjoy heading out to investigate but often wonder what having the engine fail would look like. I considered a Torqeedo 1003 but don't know if It would actually push the boat. At 35 LBS it would be fast to hang off the transom, (if I kept the battery charged )

I wonder how large your boat is .. do you think a Torqeedo would move a 2 ton boat ?
__________________
Rick Fisher is offline   Reply With Quote
Old 24 November 2020, 06:21   #18
Member
 
Country: UK - England
Town: Surrey
Boat name: Fandango
Make: Ballistic
Length: 6m +
Engine: Yamaha 150
MMSI: 232028101
Join Date: Sep 2015
Posts: 132
RIBase
Quote:
Originally Posted by Rick Fisher View Post
I have a 25 foot alum Rhib with a 200 Etec. I enjoy heading out to investigate but often wonder what having the engine fail would look like. I considered a Torqeedo 1003 but don't know if It would actually push the boat. At 35 LBS it would be fast to hang off the transom, (if I kept the battery charged )

I wonder how large your boat is .. do you think a Torqeedo would move a 2 ton boat ?
Hi Rick,
The 1103 is rated to push a boat upto 1.5T (mine is a little less than this) and I operate in an area with small tidal flow (c 2M) and I have pretty low expectations about what progress I'll make when using it.

My view is that the 1103 is not not adequate to push a 2T boat.
__________________

__________________
_monkey is online now   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off




All times are GMT -5. The time now is 09:00.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2020, vBulletin Solutions, Inc.