Anchor windlass charging

Champagne Murphy

Champagne Murphy

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After summer in the CIs I'm thinking about adding an electric windlass. I presently have a VSR charging system. What's the best option; an additional VSR and switch or a piggy-back charger like a duo charge type thingy?
 
Champagne Murphy said:
After summer in the CIs I'm thinking about adding an electric windlass. I presently have a VSR charging system. What's the best option; an additional VSR and switch or a piggy-back charger like a duo charge type thingy?
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Not sure why you would want an additional VSR. You can either have a dedicated battery charged by the engine, or you can use one of the existing battery banks. Some wire to the house bank and some to the engine start.
 
You're obviously assuming that you need a dedicated battery up in the bow, and are considering how to charge it. My suggestion would be to not bother with a separate battery, do the volt-drop calculations, and simply run big wiring from the main bank to the windlass. It's simpler, takes up less space, has less to go wrong, and (though I haven't priced up the parts for the different options) I suspect works out about the same price or cheaper. I have a system like this installed by the previous owner, and it works fine.

Pete
 
+1 with prv.
As a liveaboard, not the least of the arguments against a dedicated battery is that if a battery is using up space on board, I want to be able to use it for more than five minutes per day (engine start battery excepted, of course).

Another argument against a dedicated windlass battery is that the cabling to charge it from the alternator must be almost as big as the cabling you'd run from your existing batteries to the windlass. However, a clever alternative I've read of is to use a small dedicated charger for the windlass battery, which thus requires much smaller cables, rather than charge directly from the alternator. Despite the high load, a windlass actually draws far less than you might imagine. Even 5 minutes grunting away at 100A (which it will continuously draw only rarely, if ever) is only 8Ah. Even allowing for the difference in Ah efficiency between high and low loads, this is small beer.
 
PRV you've hit the nail on the head, I should have been more detailed. All the stuff I've been taught says fat wires from battery to load and small wires from battery to alternator. I did consider using the domestic bank but it isn't huge (we manage by reducing load, LEDs and suchlike) but the windlass supplier thought it a poor idea.
So normal 'deep cycle' marine type OK?
 
The cheapest and best solution is to run cables from either the starter battery or the domestic bank. Many people use welding cable, as it's more flexible and thus easier to feed through. The engine is usually running during windlass operation, so there's no real risk of damaging batteries.

If you add a battery next to the windlass, you'll still need big cables through the boat unless you invest in some sort of "shadow charger" product.
 
Champagne Murphy said:
All the stuff I've been taught says fat wires from battery to load and small wires from battery to alternator
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To a degree, but it's as more to do with the length of the cables, as alluded to by prv, above.
Most 1kW windlasses draw 100A, max (rating of breaker).
Some alternators produce more, although 60 to 70A is more typical. Not a great difference.
But alternators tend to be quite close to the battery bank, so the cabling is shorter...as compared to a windlass which might be a considerable distance from the batteries.
However, if you want a battery close to the windlass and charged by the alternator, that's a long run = thick cables.

For instance for a 3% voltage drop, a 60A alternator five feet from the battery needs a minimum only 13 sq.mm cable.
But move the battery 20 feet away and it needs at least 42sq.mm cable.

pvb's right about welding cable. It's also relatively cheap.
 
Ours is wired directly into the house battery bank and I did put a temperature gauge on the cable to see if they where getting warm (which they where not). Out of interest, and I have now removed it, our system had a relay that prevented the windlass from being used unless the engine was running
 
SeamanStaines said:
Ours is wired directly into the house battery bank and I did put a temperature gauge on the cable to see if they where getting warm (which they where not). Out of interest, and I have now removed it, our system had a relay that prevented the windlass from being used unless the engine was running
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You were right to remove that relay, it could have created a difficult situation.
 
prv said:
Probably, but I still wouldn't do it that way.

Get something like this: http://www.iem-services.co.uk/showdetails.asp?id=1074 and wire it up to your normal bank. (Note I haven't done any calcs on whether that's actually the correct cable size, we'd need to know the distance to work that out.)

Pete
Click to expand...

Probably about 6m from batteries to windlass site. Motor wattage is specified at 1000w (Pacific VS1000) and draw 25A
Thanks very much for all the advice
 
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