Electric trolling motor vs Petrol outboard
- Thread starter MagicalArmchair
- Start date
AMCD300
Well-Known Member
Friend of mine has an electric outboard for his tender. He carries his battery to the boat everytime he sails - it is the size of a small golf-cart battery and quite light and manageable. He puts it on charge at home.
Great experience being in a tender with no sound from a 2-stroke...
Go electric. Just make sure you can charge it on board if you go away for a trip.
Andy
Great experience being in a tender with no sound from a 2-stroke...
Go electric. Just make sure you can charge it on board if you go away for a trip.
Andy
nigelmercier
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That was a Bison?
Jump leads across the starter battery when the engine is running?
Slocumotion
Well-Known Member
You got it out of me . You're a real terrier when you're onto something !
nestawayboats
Well-Known Member
Torqeedo 12 volt charging - no need for an inverter
You don't need to use an inverter if you have a 12 volt DC system on your yacht, camper van, etc. The Torqeedo 503 and 1003 batteries are charged by 12 volts DC (if you don't believe me, look at the output on your mains charger) so you can charge directly from a 12 volt source.
Direct charging is much more efficient than converting 12 volts to mains via your inverter, and then converting it back to 12 volts again via your Torqeedo mains charger - even if the inverter and the charger were both 90% efficient you "waste" approx 20%.
This is significant if you're relying on the yacht's domestic batteries to re-charge your Torqeedo, ie at anchor, on a swinging mooring etc. (If you're plugged into the mains at a marina it doesn't really matter at all, I doubt you could measure the cost difference.) It also means you don't have to buy an inverter, if you don't already have one.
Torqeedo don't make the appropriate lead, but do make reference to this possibility in the instruction manual. The basic cable would be fairly simple to make yourself, but you do have to be careful about getting the polarity right - both in the specific lead, and any other supply cabling between it and the yacht's battery system. You also need to find the right-size input plug etc.
If you're not confident about getting the polarity right there are a couple of after-market 12 volt charging leads on the market, including (at risk of being commercial here, sorry) one that we make. Ours has built-in polarity protection, so it won't toast your battery even if, for example, the cigar lighter socket on the yacht is wired up incorrectly.
The Torqeedo batteries do have built-in over-voltage protection, but DC-direct cables should only be used with a 12 volt DC system. However you can still use them if the yacht's main engine is on, ie the 12 volt system is running at 14.4 volts or thereabouts (cut-out seems to be at 16 volts).
I almost certainly shouldn't mention that if you buy a Torqeedo from us you get a 12 volt DC charging cable thrown in - but we think it's so useful that it should be included as standard, so we do. One example, apart from charging on board, is that if you forget to charge up your battery before driving down to the boat, with a 12 volt DC cable you can top it up in the car during the journey.
Ian Thomson
Nestaway Boats Ltd
You don't need to use an inverter if you have a 12 volt DC system on your yacht, camper van, etc. The Torqeedo 503 and 1003 batteries are charged by 12 volts DC (if you don't believe me, look at the output on your mains charger) so you can charge directly from a 12 volt source.
Direct charging is much more efficient than converting 12 volts to mains via your inverter, and then converting it back to 12 volts again via your Torqeedo mains charger - even if the inverter and the charger were both 90% efficient you "waste" approx 20%.
This is significant if you're relying on the yacht's domestic batteries to re-charge your Torqeedo, ie at anchor, on a swinging mooring etc. (If you're plugged into the mains at a marina it doesn't really matter at all, I doubt you could measure the cost difference.) It also means you don't have to buy an inverter, if you don't already have one.
Torqeedo don't make the appropriate lead, but do make reference to this possibility in the instruction manual. The basic cable would be fairly simple to make yourself, but you do have to be careful about getting the polarity right - both in the specific lead, and any other supply cabling between it and the yacht's battery system. You also need to find the right-size input plug etc.
If you're not confident about getting the polarity right there are a couple of after-market 12 volt charging leads on the market, including (at risk of being commercial here, sorry) one that we make. Ours has built-in polarity protection, so it won't toast your battery even if, for example, the cigar lighter socket on the yacht is wired up incorrectly.
The Torqeedo batteries do have built-in over-voltage protection, but DC-direct cables should only be used with a 12 volt DC system. However you can still use them if the yacht's main engine is on, ie the 12 volt system is running at 14.4 volts or thereabouts (cut-out seems to be at 16 volts).
I almost certainly shouldn't mention that if you buy a Torqeedo from us you get a 12 volt DC charging cable thrown in - but we think it's so useful that it should be included as standard, so we do. One example, apart from charging on board, is that if you forget to charge up your battery before driving down to the boat, with a 12 volt DC cable you can top it up in the car during the journey.
Ian Thomson
Nestaway Boats Ltd
FWB
N/A
@Nestaway... I had already considered this and had made up a cable. I am waiting a reply from Torqeedo about using it. But you have answered my questions bar one.... What fuse should I use in the cigar plug ?
Also, I understand that the battery has an internal 4amp fuse. I have a stabilised 12v DC/DC converter but it puts out 5.3amps so presumably I can't use it?
OK have just spoken to someone at Torqeedo. My cable works perfectly and am using a 3amp fuse. 4amps in and correct polarity vital!
To those non believers ... I have been using my motor for several days now without recharging with some fairly long trips and the battery is 55% full.
Also, I understand that the battery has an internal 4amp fuse. I have a stabilised 12v DC/DC converter but it puts out 5.3amps so presumably I can't use it?
OK have just spoken to someone at Torqeedo. My cable works perfectly and am using a 3amp fuse. 4amps in and correct polarity vital!
To those non believers ... I have been using my motor for several days now without recharging with some fairly long trips and the battery is 55% full.
Last edited:
nestawayboats
Well-Known Member
@Nestaway... I had already considered this and had made up a cable. I am waiting a reply from Torqeedo about using it. But you have answered my questions bar one.... What fuse should I use in the cigar plug ?
Also, I understand that the battery has an internal 4amp fuse. I have a stabilised 12v DC/DC converter but it puts out 5.3amps so presumably I can't use it?
OK have just spoken to someone at Torqeedo. My cable works perfectly and am using a 3amp fuse. 4amps in and correct polarity vital!
To those non believers ... I have been using my motor for several days now without recharging with some fairly long trips and the battery is 55% full.
Dylan, the 3amp fuse will probably be OK, but at or near the limit all the time.
Re the 4amp internal fuse (in the Torqeedo battery), yes this does provide protection but should not be relied on. It's quite an involved process to take the case apart to replace it and I believe that doing so invalidates the warranty unless you are a Torqeedo service agent.
Just to be absolutely clear to anyone who wishes to make their own 12 volt DC charging cable, you MUST GET THE POLARITY RIGHT.
Re your other point, "Range Anxiety" is either first or second in most potential customers' minds (ie before or after the price). But for most - we know not all - people, it is enough for the way they actually use their motors, particularly on yacht tenders. For example a couple of trips to/from your home port swinging mooring, then at your destination harbour a quick trip to the pub, then taking everything ashore again back at your home port. The 520Wh battery supplied (since 2012) with the 1003 model will do all of that, so long as you don't run it flat out. At half power the 1003 will drive a typical over-loaded inflatable just as fast as a 3.5hp petrol; neither motor will get it on the plane anyway. In fact the Torqeedo motor/propeller design is better optimised for driving heavy loads at displacement speeds than most if not all petrol outboards.
The 12 volt DC charging cable also gives you a crude "range-extending" device if required, if you can take a 12 volt battery in the dinghy with you. It will constantly charge the Torqeedo at somewhere around 30-35 Watts, even when you're using it, and also while you're sitting in the pub etc. If it's half an hour each way to the pub, and you're at the pub for three hours, then during that four hours you've "put back" at least 120W, and effectively increased the range by nearly 25% (120/520). This won't be necessary most of the time but on occasions when you know the journey could be marginal that 25% might make all the difference.
The more expensive "range-extending device" is a second Torqeedo battery. You need to take tide and wind into account of course but as a general rule if you can get there on one of the batteries then you will be able to get back on the other.
Ian
Nestaway Boats Ltd
lw395
Well-Known Member
To charge a 12V battery from another 12V battery requires more than a cable.
You need 13.8 just to float charge it, and to get any useful current in, over 14V is normal.
Does the Torquedo perhaps have a boost circuit built in? Or is its internal battery less than 12V?
I went to a talk by a couple of sailors who'd bumbled around the pacific islands for a year. They reckoned a lot of the yachts they met spent a lot of time looking for petrol for their RIB tenders. These guys had a sailing tender which they decided was a great asset.
Perhaps electric would be good anywhere where getting petrol is a pain, which can include a lot of places.
But two cans went a long way with our Yamaha.
In most harbours you can trade a beer or something for enough fuel to fill your o/b, that's harder to do with electric.
I'd suggest sorting out a lead to charge it from the pub.
You need 13.8 just to float charge it, and to get any useful current in, over 14V is normal.
Does the Torquedo perhaps have a boost circuit built in? Or is its internal battery less than 12V?
I went to a talk by a couple of sailors who'd bumbled around the pacific islands for a year. They reckoned a lot of the yachts they met spent a lot of time looking for petrol for their RIB tenders. These guys had a sailing tender which they decided was a great asset.
Perhaps electric would be good anywhere where getting petrol is a pain, which can include a lot of places.
But two cans went a long way with our Yamaha.
In most harbours you can trade a beer or something for enough fuel to fill your o/b, that's harder to do with electric.
I'd suggest sorting out a lead to charge it from the pub.
nigelmercier
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No problem to charge a 12V battery whilst it is connected to another battery that is being charged; we do it every time we charge our domestic banks. The 12V charging input will be a nominal 12V.
nestawayboats
Well-Known Member
The Torqeedo batteries we are talking about - for the 1003 and 503 motors - output something like 29.6 volts, but definitely charge from a 12 volt DC source (including the "official" Torqeedo mains-powered charger). And on the bench we've found they'll charge anywhere from about 11 volts to 16 volts. So as you suggest there must be some kind of voltage booster built in to the charging circuit.
Also as you suggest taking the battery to the pub and plugging in the mains charger is a good way to top up, certainly if you're there for a couple of hours or more. I can't remember the input voltage requirements now but the mains charger comes with both European and American style plugs, so I would guess it's fairly tolerant. Somewhat surprisingly it does not come with a UK plug - but if you buy the motor from us we put a clip-in adapter in the box at the same time we put our 12 volt DC charging lead in.
I can't deny it's quicker to put a litre of petrol in a tank than to charge up the battery. But electricity doesn't smell so bad, and you can store a Torqeedo motor laid down on any side you want to. It won't wake the neighbours up when you're taking the dog ashore at 5am. And it divides into pieces, the heaviest of which is 9kg; doesn't have a choke or starter cord to fiddle about with, etc etc.
Also as you suggest taking the battery to the pub and plugging in the mains charger is a good way to top up, certainly if you're there for a couple of hours or more. I can't remember the input voltage requirements now but the mains charger comes with both European and American style plugs, so I would guess it's fairly tolerant. Somewhat surprisingly it does not come with a UK plug - but if you buy the motor from us we put a clip-in adapter in the box at the same time we put our 12 volt DC charging lead in.
I can't deny it's quicker to put a litre of petrol in a tank than to charge up the battery. But electricity doesn't smell so bad, and you can store a Torqeedo motor laid down on any side you want to. It won't wake the neighbours up when you're taking the dog ashore at 5am. And it divides into pieces, the heaviest of which is 9kg; doesn't have a choke or starter cord to fiddle about with, etc etc.
Slocumotion
Well-Known Member
If you are still considering the bison - I've just taken delivery of a Flover to replace mine,( which packed up) Not been able to get it on the water yet but just unwrapping it and running it in the shed, it's cheese to the bison's chalk (or should that be the other way around?) Everything about it looks and feels superior.
nigelmercier
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http://www.floveroutboard.co.uk/
Which model did you get, and what type of craft does it power?
I've got a 2.4m inflatable, flat bottom. I want to get a couple of MPH in an adverse wind/current.
Slocumotion
Well-Known Member
Good evening Nigel,
It's the 45, on an Orkney Boats A11 (quite a hefty 11ft GRP dinghy - 2 of us can't lift/carry it) I've just this minute come back from my mooring and I'd say the 4mph the floverboat spreadsheet says is about right . I'll take a handheld GPS out tomorrow evening and confirm. This being Orkney we can probably rustle up some adverse wind easily enough.
It's the 45, on an Orkney Boats A11 (quite a hefty 11ft GRP dinghy - 2 of us can't lift/carry it) I've just this minute come back from my mooring and I'd say the 4mph the floverboat spreadsheet says is about right . I'll take a handheld GPS out tomorrow evening and confirm. This being Orkney we can probably rustle up some adverse wind easily enough.
Slocumotion
Well-Known Member
3.6 mph with the wind and 3 against and just for completeness, yes I did drift at about .6mph downwind.
I like the long shaft that is infinitely variable - you can plunge it deeply enough to not waste power stirring up a froth on the surface. And as compared to rowing you can trim your tender much more effectively. I find with two up I could do with another rowing position right forward. With the passenger aft I'm dragging the transom through the water. Up forward and it's very difficult to steer.
I would have gone for the 55 if money were no object.(The Bison was a 55 and it had plenty of "grunt" - until it suddenly had none that is,)
nigelmercier
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Flover have discontinued the 55, don't know why. I can get a good deal out of them if I review the 45 on my Bavaria forum.
Slocumotion
Well-Known Member
Re the poorly Bison. Fishing Mad have very kindly supplied a new brush carrier plate complete with brushes , springs etc so it's now running again. What to do with it though? Twin-engined tender? Hand-held bow thruster?