windlass consumption

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novice04

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Planning to install a 700W/12V el. windlass (Quick, Aster) on 31ft wooden boat. Alternator produces 38A/h, there are two batteries (65+60A) with 1-2-all-0 switch, the windlass pulls 95A @ working load and the speed is some 11m per minute @ w.l. (per manufacturer's data). How does one calculate the actual consumption - i.e. do I have enough charging capacity for this windlass?
Also, what is the practical advantage of a drum - can it be operated separately from the gipsy?
All help and tips greately appreciated!
 
you will need 95x3minutes divided by 60 =approx5amp/hrs.worked out that you are pulling in 33meters of chain as a max.You will need some fairly hefty cable size depending on length of run.Batteries should be OK as you are not anchoring every 5 mins!
 
If your anchor cable is all chain then a drum is of comparitively little use. If your cable is chain and rope , you could run the rope around the chain gypsy (most modern ones are designed for this) but it is not good for the rope,

Personally I have a drum so that I can haul in the rope on the drum, and then change over to the gypsy for the chain.
 
Have you considered putting a dedicated windlass battery in the bows? The cables you would need to run in order to trickle charge this battery would be much less substantial than the ones needed to go from your existing battery bank to the windlass.
 
Nedmin's calculation shows that in terms of draining a battery, the windlass is trivial because it is used for such a short time. The important factor is the size of the current which of course needs very large cables.

When using the windlass you should always have the engine running on fast tickover (1200 rpm min). The alternator will supply most of the current with the battery making up the shortfall.
 
Thanks all - just the kind of info I need!
Talbot: But, does this mean that I can use another rope on the drum (say, anchor is up - gipsy is "occupied") to pull up/in something else independently of the gipsy. Like, is there some gear or something engaging the drum, while gipsy is still/disengaged?
Simon: I red on some previous posts that in some cases that represents too much of a hassle vs. benefits. I'd like to think that mine is such a case!?
Just remembered an important question: Does the whole assembly (bow-roller to windlass) have to be centered right on the boat's longitudinal axis? Due to a hatch, I'll have to install everything some 30cm to starboard side. Are there any practical implications of this?? (My hull profile at the bow allows me to pull anchor up on that spot without scratching it)
I'd like to arm myself with some understanding of all this before talking to potential supplier!
Thanks again!
 
Not sure what the 'Quick' recommendations are, but for 'Lofrans' windlasses, it's recommended that for a 12v 700w windlass you'll need a minimum battery capacity of 100 A/hr. So, as long you don't mind switching the engine start battery in parallel with your service battery then you'll be ok.

I recently installed a 12v 1000w Lofrans (they recommend 150 A/hr capacity) which is connected to my service & engine battery giving approx 200A/hr and haven't had any problems, although I'll probably upgrade the service bank to 200A/hr so that the engine battery can be left out of the circuit. For comparitive purposes, my engine's a 13.5HP Beta, with a standard 40 Amp alternator

If I recall correctly, the overall distance from the batteries to the windlass was about 7.5m and I've used 35mm sq arc welding cable. Some may say that arc welding cable isn't suitable, but IMHO, if it can operate in it's normal service effectively being 'shorted', then I reckon it's fine for windlasses - I also managed to source it 'tinned'.
 
Not necessarily....

[ QUOTE ]
The cables you would need to run in order to trickle charge this battery would be much less substantial than the ones needed to go from your existing battery bank to the windlass.

[/ QUOTE ]

This isn't necessarily true. If you want to use light cables to charge a separate windlass battery, you must disconnect the windlass battery from the charging cables before operating the windlass. Otherwise, a large current will be drawn along the charging cables, especially if the engine is running.
 
Also, I seem to think that with the 'Quick' windlasses fitted with a drum, if the clutch is slackened off, then the drum can be operated independently of the gypsy, but not vice versa.
 
I would put it on the start battery,welding cable is too big a x-section than you need,unless its free!!! I would use 16sq.mm that is slightly below your current rating but that is for continuous use.I would also put an in-line fuse in the circuit of about 200amps, it would be good practise to put a battery switch in also. If you start your engine on a cold day it will take more than 95amps so you should be OK.if not you can always put a bigger start battery in.
 
Re: Not necessarily....

[ QUOTE ]
Quote:
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The cables you would need to run in order to trickle charge this battery would be much less substantial than the ones needed to go from your existing battery bank to the windlass.


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This isn't necessarily true. If you want to use light cables to charge a separate windlass battery, you must disconnect the windlass battery from the charging cables before operating the windlass. Otherwise, a large current will be drawn along the charging cables, especially if the engine is running.


[/ QUOTE ]
Yes you would have to put a switch on the charging cables, but i'm guessing that the cost and weight of a dedicated battery is about the same as that of the heavy duty cables needed to run from battery bank to windlass on a 35 footer. By installing a dedicated battery instead you have 3 benefits:
1. There is an emergency battery on board should your starter battery fail
2. There is virtually no voltage drop as the cable run from battery to windlass is very short
3. You can buy the optimum battery for the task rather than inappropriate use of combined starter/leisure batteries.

But there are installation issues with this method that may outweigh the benefits.
 
Re: Not necessarily....

"" But there are installation issues with this method that may outweigh the benefits.""


Absolutely, not the least of which is properly securing a heavy duty battery right up forward where the pitching is at it's worst, and isn't going to be improved by adding another chunk of weight!

On the question of current, the 95 amps quoted is, I believe, for the maximum (stalling) load. My 1000w Lofrans never pulls anything like the max. current in normal, everyday use. I use a 90 amp CB and it's never tripped yet.
 
Installation issues....

One of the installation issues involved is that it's necessary to have a fuse/breaker at both ends of the charging cable.
 
Re: Not necessarily....

its very difficult to advise on this forum as there are so many variables,all we can do is to advise in a safe way as far as possible.the problem is that the motors fitted to winches will be series type motors(much cheaper to produce for the power they give) unfortunately on stall the current can be tremendous,thats why i suggested a 200 amp fuse.we all know that sometimes anchors get snagged.
 
Re: Not necessarily....

My electric windlass is installed to one side of the chain hatch & works with no problems.This is as per the Hunter factory boats standard installation so it must be OK.In line would be the perfect solution but this is not always possible.
 
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