Electric Motors

[werewolf]

Hey Champs

For a small tinny, say 3.5m with a couple of ppl onboard and gear, how much thrust would one need out of an electric to make decent headway through Brisbane River currents???

Would a 40 pounder do it or would stepping up be safer???

Cheers

Matt

Post edited by: werewolf, at: 2006/10/29 18:16

[ando_04]

probly a 55lb. but may be a bit to heaver for the boat?

[Feral]

I reckon the current in the Brisbane river (tidal stretch) would be to much for an electric.

You could buy a decent second hand (or even new) 4hp outboard for the same price as the electrics would cost you anyway. (Minn Kotta 55lber is about $600, plus another $400 to $500 for batteries).

55lber would be plenty for the load you have in still water. A 55lb gives roughly 3/4 of a horse power, and for that size boat would probably be good for 2 or 3 knots.

In still water you could probably get away with a 44lb thrust, and say 1 battery if you not going to be out forever.

You can get \"no name\" electrics a fair bit cheaper than Minkotta's, if you go fresh water only its cheaper again - I picked my 55lber (fresh water only) up from Kmart on sale a couple of months ago for $200. A 110 to 120 AH battery will cost you around $250, and would be good for 3 to 4 hours pottering about.

[Angus]

Werewolf are you looking at this electric so you can double it up in wyvanhoe etc?

[werewolf]

Feral: Thanks for the heads up mate. Even where I'm based the current gets some serious pace up during the big tides and I had some doubts as to whether an electric would handle it. According to an email I got from BCF, their RT40S is $495 and the RT55s is $1019 (both salt spec) but damn thats a big jump to get to the 55 pounder! I would almost wonder whether there was a mixup... But yeah once I saw the pricing on the leccies (then add on the cost of a decent capacity battery), a second hand 4-6HP outboard was starting to sound very attractive.

I was hoping 55 pound of thrust would work out to be around 2 HP, but as Feral pointed out if its only worth about 3/4 HP she would struggle against the current!

Angus: Am I so shallow? LoL Yeah the first reason for me thinking of getting a leccy first is that it would be cheaper and secondly I could use it at Wivenhoe harassing the big catties over summer and then the big bass during winter. Seeing how getting a new saltwater spec Minn Kota leccy is going to cost big $$$, getting a \"Homebrand\" freshwater leccy from Kmart just for impoundment work sounds very smart!

The old man just went halves in a new trailer with me, so now that the transport is sorted out I can seriously start looking around. (IF i go ahead with it lol, 3 months ago I had my heart set on a double seater yak:whistle: ). It would be sweet to have a little setup before the classic though, but damn its getting close so it probably won't be ready in time. I can't wait!!!

[Feral]

Well did a quick bit of programming last night, and here is a link to a calculator for everything you need to know for electric boat motors. (about 250k download)

/>http://web.aanet.com.au/askenne/executables/EMC.zip

Its pretty rough, and the speed is calculated using the formulae used for sailing boats, and is pretty rough, but it should give a good guide. In case the name does not give you a hint, I would only recommend using this for calculating a rough idea of what to expect. Hull shape, weather conditions etc etc will have a big effect.These calculations are for still water and no wind.

Remember electrics are drastically affected by wind, tide and current! (When using an electric your boat is a displacement hull.)

[werewolf]

Feral. Cool little app you whipped together mate. Cheers!

[Brian D]

I just picked up a 54lb electric transon mount but now I am a bit worried about size. Before I take it out of the box does anyone have any idea if it will move my boat?

Also the guy said I can just wire it to my cranking battery and it'll be sweet? Do you reackon or is he FOS.

It's a Javis Marine \"Watersnake\"

[rayke1938]

brian he is FOS in large capitals. you will definately need at least 100ah deep cycle battery any bigger they get a bit heavy to lift and maneuver. The 55 will move your boat if you are only thinking of keeping position or working lily pads. You will have problems with winds and strong currents. I would gestimate that you will only get about 3 kph top speed with your outfit.

This will be ok for slow trolling lures and spinner baits etc. With my 3.9m electric tinney i get 6 kph running a 55 bow mount and a 45 stern mount.

To really get reliable performance with some safety i would suggest

option 1. pick up a small tinney and use your existing motor on that or

option 2 get a 24v 82 lb bowmount for your existing boat.

Sorry to put a damper on everything but either way its going to cost big bucks especially option 2 where you will have the cost of 2 batteries to purchace.

If you like i have a 65 lb 24v minnkota stern mount i can let you borrow to try out.

Ray

[Brian D]

Ray - here's the customising

On my big boat the battery will be charged every time I crank and run the motor but I'm with you.

I need another battery that gets charged from the motor by a gadget that Feral put me onto from Whitleys that trickle charges the battery automaticly when the motor is running, then autonmaticly shuts down the charge.

I think I can get a combo battery that is both deep cycle and crank.

At awoonga I needed something to hold me in place - everytime I started the motor to reposition it left me with the feeling that I scared the fish off. So what you say about the lilly pads is exactly what I intended it to do - so here's hoping.

Option 1 - That's my plan man - something for Hinze Dam. Haven't told the missus yet - but I do have a trailer and motor now - so that's a good start.:whistle:

option 2 - No - you just want to see me go over the bow again.:woohoo: :blush: :evil:

Keep an eye out for a tinnie please!

Ray thanks for your input - it basicly confirmed what I was thinking. you get my weekly Karma vote for that.

Post edited by: Brian D, at: 2006/12/06 15:57

[Feral]

Brian check out the software link in my post above, it should give you a rough guestimate.

My 55lb pushed Rays 4.1m glass boat at Awoonga at 5kph in top speed. Which is pretty close to what the software estimates!

Yeah you really need a deep cycle battery, some of the marine cranking batteries are deep cycle (a very few), most are sort of a compromise battery, which lean towards deep cycle, but are not truely so. You will kill a battery that is not deep cycle reasonably quickly, mind you your missus wont know the difference when you tell her \"dear the boat battery has died and I need a new, geez there dear - $200 -$250.\"

Or you could go the suggestion I made under your post where you described how you got the motor!

But before you try that - Can you leave me your boat in your will?

PS here is a good link about batteries

http://www.windsun.com/Batteries/Battery_FAQ.htm

Post edited by: Feral, at: 2006/12/07 04:24

[Brian D]

Had a look Feral - hurts my head:blush:

I got more to learn.

Given that I need a different battery - deep cycle 120 ah - would I be able to rig this type of battery to that whitley gadget and charge it from my motor?

Was the gadget called a relay?

Can I connect 2 different types of batteries with a switch between?

Can I use my existing battery for short bursts to reposition the boat without stuffing the battery?

Do you want a 12v cranking battery - it was OK last I looked but I got a bigger one now?

[rayke1938]

brian

the thing that will shorten the life of a normal battery are discharging it to flat and leaving it discharged. A normal battery is not designed to be fully discharged like a deep cycle battery.

You will get away with using your normal battery providing that you do not flatten it and make certain thet you keep it fully charged.

Say if your existing battery is 80 amphere hour you would probably get away with running the electric for 3/4 to one hour without damageing the battery and still leaving enough capacity to restart your motor.

Also be aware that if you are running your sounder and nav lights they also use power from the battery.

It would be prudent to buy a $40 jump start battery from supercheap to save the embarrasment of a flat battery.

I think that you motor has a 17 amp alternator which means that approximately that for every hour that yor run your electric on 3/4 power you would have to run your outboard for 2 hours to recharge the power you have used.

ray

[Brian D]

Thanks Ray

That helps.

I will eventually get another battery but whether I get it sorted before Glenlyon or not is a big \" I doubt it\".

The other battery will depend on the other boat, which will depend on finance, permission and timing.

[rayke1938]

i can bring along a spare 100 ah deep cycle battery and charger to glenlyon if you like. a lot of people chasing cod troll with an electric as they only seem to tro;; at 1 - 2 kph.

ray

[Feral]

Brian D wrote:

Had a look Feral - hurts my head:blush:

I got more to learn.

Given that I need a different battery - deep cycle 120 ah - would I be able to rig this type of battery to that whitley gadget and charge it from my motor?

Brian,

That gadget will charge both batteries, but for a deep cycle best to count of having to charge it from mains. If your hooting about on the outboard, and only using the electric for manouvering a little bit, the motor would probably charge it just fine. Easiest way to check on charge is to use a voltmeter to check on battery condition, dont let it drop below about 11.4 volts for a deep cycle. I put a list of voltage verses battery life somewhere where on the site - I was talking about mounting a switch panel with a volt meter for my battery's.

But feeding the details of your boat into my software, (using my highly technical ability to pluck accurate figures out of thin air :whistle: ) I get the folowing

Assume

your hull length in the water is about 12foot

Your boat weighs about 2000lb (from knowing braked single axle trailer, trailer should be about 250 kilo's estimate boat, motor etc weighs 750 kilo's)

using a 100ah battery

Gives the following

Max speed - 3.7k's or 2.0 knots

battery life 2 to 3 hours fishing

But you have a big profile boat, wind would knock that about a fair bit.

Post edited by: Feral, at: 2006/12/07 17:51

Post edited by: Feral, at: 2006/12/07 19:05

[Feral]

Oops sorry fella's the version of the software I posted did not have the metric boxes on it (put the metric values in the boxes and it puts the imperial values in for you.)

The link now leads to the proper version!

http://web.aanet.com.au/askenne/executables/EMC.zip

[Brian D]

Good on ya - as if I need more mind fcks -thanks

haahhahhaahah

Do me a favour - Can you and Ray have a look at the polycraft site and let me know what you think about the tender for a electric fresh boat. I can get it new for $1200.

Do you think it will be stable enough?

[Feral]

What polycraft site?

Plain hulls are reasonably cheap in alloy, IE a 3.5m goes for around a grand or a bit more. But that is bare, no trailer, no motor, no gear.

Although I suppose you have a trailer we could \"adjust\",

note- your spare trailer is probably not suitable for a poly boat, apparently they need all slides, no rollers except the \"pickup\" one at the back, so if you went poly and wanted to put it on your trailer, you would have to invest in some slides)

Post edited by: Feral, at: 2006/12/08 04:26

[rayke1938]

Brian I assume that you will be trailering any proposed new boat. the polycraft looks ok on paper and should be stable. Its a bit too heave to cartop as it weighs 80kg.

Have you concidered a used tinney/ At the moment there is a quintrex 3.85 explorer and trailer that is only 3 months old advertised in yesterdays trading post for $1650

Primary Photo

Quintrex 385 Explorer 2006, 3 Months Old, Rego till next year, $1650.00 Surf Marine 5-9 Greenway Drive Tweed Heads South Paul Ph 5569 6000

Logo

Seller's other items

STATE: QLD

SOURCE: Dealer Online Ads (Personal Trading Post)

this is around the new price for the basic hull and is an excellent freshwater boat plus it will take up to 30hp outboard.

I had an explorer before my present boat and the only fault i had with it is the ride in choppy water. i could not fault it for stability.

Ray

[Brian D]

Feral wrote:

Brian D wrote:

Had a look Feral - hurts my head:blush:

I got more to learn.

Given that I need a different battery - deep cycle 120 ah - would I be able to rig this type of battery to that whitley gadget and charge it from my motor?

Brian,

That gadget will charge both batteries, but for a deep cycle best to count of having to charge it from mains. If your hooting about on the outboard, and only using the electric for manouvering a little bit, the motor would probably charge it just fine. Easiest way to check on charge is to use a voltmeter to check on battery condition, dont let it drop below about 11.4 volts for a deep cycle. I put a list of voltage verses battery life somewhere where on the site - I was talking about mounting a switch panel with a volt meter for my battery's.

Assume

your hull length in the water is about 12foot

Your boat weighs about 2000lb (from knowing braked single axle trailer, trailer should be about 250 kilo's estimate boat, motor etc weighs 750 kilo's)

using a 100ah battery

Gives the following

Max speed - 3.7k's or 2.0 knots

battery life 2 to 3 hours fishing

Post edited by: Feral, at: 2006/12/07 17:51<br><br>Post edited by: Feral, at: 2006/12/07 19:05

Thanks Feral

I missed that post - we must have been posting at the same time.

Boat is 15' Bow to transom and about 1800kg loaded (I think.

I only intend to use the electric as a positioning agent in the cruise craft and am looking for another hull for fresh - be alloy or poly - I don't mind as long as it's stable and light.

I have trailer and electric and all the other gear - so just a hull.

Post edited by: Brian D, at: 2006/12/09 06:38

[Brian D]

Feral wrote:

What polycraft site?

Plain hulls are reasonably cheap in alloy, IE a 3.5m goes for around a grand or a bit more. But that is bare, no trailer, no motor, no gear.

Although I suppose you have a trailer we could \"adjust\",

note- your spare trailer is probably not suitable for a poly boat, apparently they need all slides, no rollers except the \"pickup\" one at the back, so if you went poly and wanted to put it on your trailer, you would have to invest in some slides)<br><br>Post edited by: Feral, at: 2006/12/08 04:26

Missed this one too

About the trailer Yeah that's what I was thinking - depending on the hull will determine the slides.

If it's a alloy hull it has to be a flat bottom punt.

Feral/Ray

I know I put the cart before the horse by buying the motor (I have a problem) but now I gotta figure out what size hull- Say I weigh 100kg and I put another 100kg ofr gear and another bloke - that's 300kg.

Given that the motor is 54lb - What size punt do I need to be comfortable and movable?

[Feral]

Dunno,

but load capacity is based on 75 kilo's per occupant,plus 15 kilos gear per person you would need something with 3 person capacity for that load

I'd reckon a 10 footer would do, but 12 would be more comfortable.

Ferg and I use a 2.3m (7'10\") punt with minimal gear, (and 30 kilo's of batteries!)but dont have a lot of freeboard on the back about 5 or 6\".

Post edited by: Feral, at: 2006/12/09 07:35

[rayke1938]

brian it is also a matter of comfort and space while you are fishing i would recommend not under3.6 up to 4m long.

your motor will handle 4m long but will be a bit slow into strong winds.

other things to concider are height of seats. you do not want to be fishing for long periods with your knees around your ears. installing an extra seat will fix this.

a john type punt works quite well and is the fastest on the water providing you keep most of the weight down the back but they bang a bit going into a chop.

the quintrex explorer range are good and the allycraft in the same style are also good.

sometimes you can pick up a secont hand fibreglass hull they are a bit heavier but are much more quieter to fish out of. I have been fishing in my tinney with a mate beside me in his fibreglass boat and he has been catching fish whilst i havent. i blame this on the noise of the waves on my tinney.They also need less maitenance in that you dont have to wast them out all the time and also dont have to worry about corrosion.

Ray

[Brian D]

As useual you guys raise some good points - that's why I asked - thanks again

The chop thing - I didn't think it so important but after Awoonga I am thinking of a 5.4m cat! Well maybe not but I take your point.

Should be looking back at a canoe? I went of em cause they cost about the same as a punt but not as comfortable , less stable and can't carry as much gear.

I don't mind the bang factor when moving but hate it when anchored.

I am thinking for only for hinze and baroon type dams where only elect motors are ok - so is bang factor important?

[rayke1938]

JOHN STYLE PUNTS ARE IDEAL AT HINZE AND BAROON ALSO OK FOR SAMPSONVALE WHEN IF IT EVER RAINS AGAIN.

RAY

[rayke1938]

brian something like this may be worth looking at and its in your area. looks like the photos on ebay wont transfer but if you look at it on ebay you can see.

ray

Seller: rudym6767( 145Feedback score is 100 to 499)

Feedback: 100% Positive

Member: since 06-Jun-05 in Australia

Read feedback comments

Add to Favourite Sellers

View seller's other items

Ask seller a question

Email the seller

Buy safely

1. Check the seller's reputation

Score: 145 | 100% Positive

Read feedback comments

2. Learn how you are protected

Read our safe buying tips

Description Seller assumes all responsibility for listing this item.

Item Specifics

Condition:

Used

hi

up for sale is a 12 foot fibreglass boat with 2hp suzuki motor, the trailer is registed (as picture shows), the motor runs ok ,over all the boat is in ok condition needs a little tlc . it was used to go out to a moored boat (therefore it floats), trailer is in alright condition for it age

sold as is

(this item is listed else where )

buyer is to arrange pick up

any questions please ask

Select a picture

00186

Learn about eBay counters

Postage, payment details and return policy

Services available

Check item description and payment instructions or contact seller for details.

Seller's payment instructions

When auction is finished please email me rudym6767@hotmail.com and we will organise payment which will be bank deposit thanks rudy

Payment methods accepted

#

Other - See Seller's payment instructions for payment methods accepted

#

Bank Deposit

eBay prohibits the use of instant cash transfer services such as Western Union or Moneygram. Learn about payment methods.

Ready to bid help

12ft BOAT

Item title: 12ft BOAT

Starting bid: AU $400.00

Your maximum bid:

AU $

(Enter AU $400.00 or more)

You will confirm in the next step.

eBay automatically bids on your behalf up to your maximum bid.

Learn about bidding.

What else can you do?

Go backBack to list of items | Ask seller a question | Add to Calendar | Report this item | Printer Version

About eBay | Announcements | Register | Security Centre | Feedback Forum | Site Map | Education Centre | Help

Copyright © 1995-2006 eBay Inc. All Rights Reserved. Designated trademarks and brands are the property of their respective owners. Use of this Web site constitutes acceptance of the eBay User Agreement and Privacy Policy.

eBay official time

[Brian D]

Thanks Ray - your a friggin gem - it looks spot on.

More karma for you

I sent the seller a message - hope I get it -

Told him $400 cash pick up today -

[Feral]

Here is a quick Pic of how I store my electric, saves space and is remarkably stable (all the weight is in the bottom of the motor, so very hard to knock it over. [img size=399]http://www.australianfishing.com.au/media/kunena/attachments/legacy/images/how_to_store_your_electric.jpg

[rayke1938]

brian look in your pm re boat but ring my mobile 0403072325 as wife has just got on phone to her sister and will talk for hours about what a mongrell i am.

ray