Windlass battery

[Storyline]

I am installing a powered windlass on our 36 footer. It is around 8m from the batteries and so according to the manual it requires a wire size of 25sq mm. I have read about having a separate battery near the windlass which would mean a reduced wire size of 16sq mm. It occurs to me that I am going to need a sizeable wire to link this secondary battery to the engine battery so what is the benefit of a separate battery (other than increased ah's)? If it is better to have a dedicated battery then what size wire should I use to join it to the starter battery?

Many thanks for any advice

 

[halcyon]

The second battery just supplies the bow load, in your case the windlass.

This means the cable to the front is only for charge current to the battery in the bow, not high current drawn by the windlass.

This battery will need a charge control, if you do not have a battery sensed alternator / smart reg, do not use blocking diodes. You will need a relay to minimise volt drop.

Brian

 

[Seanick]

Re: Windlass battery *DELETED* *DELETED*

Confused /forums/images/graemlins/confused.gif

 

[Storyline]

Thanks Brian.

I had planned to just connect the new windlass battery in parallel with the engine battery via a fuse. In this case it would be charged when the engine battery is selected by our battery switch and I would also run the engine when using the windlass i.e. have the two batteries acting as one.

Is this plan OK?

 

[PembrokeshirePromise]

Long thread here ....

http://www.ybw.com/forums/showthreaded.php/Cat/0/Number/1594609/page/

I installed a separate bow batter with an Echo charge ( http://www.power-store.com/view-item.asp?itemid=1270&id=209& ) - can have much lighter cable runs which was important to me. Seems to work fine for me.

 

[halcyon]

Interesting idea.

When you run the windlass with the engine running, you will draw power from the local battery, low volt drop. With with the alternator running, this may compensate for volt drop in run to bow, so also part feed the windlass.

When you start the engine, most power will come from the engine battery, being the local one with low volt drop, with a little from the bow due to volt drop in cable from bow.

Problems, you can run down both bow and engine battery with windlass if engine is not run.

If running the windlass with engine running only, you may well be as well just using engine battery, and heavy cable to bow.

To work the system you may have to fit the same size cable as above, so not saving anything with the bow battery.

You could have the worst of both worlds.

What amperage are you looking at for windlass and engine start ?

Brian

 

[William_H]

I think you will be better off with heavy cables and rely on the engine battery to provide the current. Having a bow battery ,means another battery to get old and need replacing however of course if you want more battery capacity for engine starting the extra battery will be contributory to engine starting if it is wired in paralell. However it is not good to have batteries hard wired in parallel when one starts to fail. Hence Halcyon's comment re a charge controller (or Volt sensing relay to connect the bow battery for charging.) This device will avert the the engine battery being discharged if engine is not running. ie bow battery is not in paralell with engine battery but can receive a charge from it and some supporting current when engine is running.
It can ll get complicated so I reiterate just fit heavy cables to the engine battery. olewill

 

[Storyline]

Thanks all.

I plan to investigate the route and see how easy it is to get heavy cable in.

The windlass is rated at 1000W and draws 85A.

 

[ebbtide]

With such authoratative inputs I hate to demur, but replacing 'windlass' with 'bow thruster' ,after several battery failures I have come to accept that no battery should be linked to any other.
So charge 'em together but use them separately.
(see Moody Nick's recent lament when all three batteries failed.)

IMHO there should be no battery forward of the saloon.

 

[tabernacleman]

well I was about to post for advice in a new thread re windlass solenoid and low and behold I see this thread, Q - I have a new SL 1500 12v vert windlass which needs a 'reversing' solenoid. The SL job is expensive, there is a Quick T503 solenoid which might suit but marine mega store wont commit, they have informed where full spec available, it is at www.quickitaly.com/index.asp?.lng=us opinions re suitability appreciated. I have decided, after reading thread, against the seperate battery for this windlass now going to wire in from the s/ battery on the snowgoose elite, anyone been there?

 

[Ian_Edwards]

Hi,
I'm just in the process of fitting a battery for the windlass because of problem I had last season running the windlass off the domestic batteries with the windlass wired so that it will only run with whilst the engine is running and the alternator charging. The windlass is 1000watt, 80amps or so and the alternator 115amps, the cables to the bow are 35mm^2. With this set-up the Raymarine system dropped out (low voltage), when running the windlass even with the engine running at 1500rpm.
In addition there was no sensible way of getting the anchor up if the engine won’t start (and we had that happen), I don’t fancy hauling by hand 60m of 10mm chain, a big anchor and a 40ft boat in any kind of wind.
I’m installing an 110amp hour sealed AGM with a voltage sensitive relay in parallel with the domestic batteries. The battery is going in a “water proof “box, to about IP66 standard in the anchor locker, with a thermo magnetic switch (rated at 80amps) between the bow battery and the windlass.
I don’t know how well all this will work as yet ... but I’ve done the sums, the low impedance of the AGM combined with the short cable run (less an 1m) of 50mm^2 cable should mean that the bow battery will take most of the load even when the engine is running and the 110amphour battery should give me several shots at getting the anchor up if the engine won’t start, it should take the windlass 4mins at full load speed to get 60m of chain on board. The voltage sensitive relay combined with the 35mm^2 cable (I’m using the existing cable to charge the battery) should mean that the bow battery will charge reasonable well when the engine is running and be isolated from the domestic supply when it’s not.
Hope this helps.

 

[pampas]

If you parallel the start battery to the windlass battery the joining cables must be really thick or fit a diode in the thinner cable as starting the engine currents will be drawn from both batterys hopes this makes sense.

 

[vyv_cox]

I decided for a variety of reasons, i.e. no decent location for a dedicated battery, additional maintenance, cost, etc, to run heavy cables from my battery bank to feed my windlass. I used welding cable, supplied by my chandler, which is flexible to assist installation and relatively cheap. The windlass has now been installed for something like 7 years, has never given any problems and battery life has not been compromised at all. Although I normally only use the windlass when the engine is running there are times, such as taking up anchor warp when stern-to and suchlike, that I use it without starting the engine.

 

[Cloven]

If you do go for the separate battery , consider getting a Red Flash battery. They are tiny compared to the normal type and can be installed in any orientation if needs be. They are sold as dedicated starter batteries in that they give out a big load and then recharge quickly which is pretty well what you do with a power windlass.

 

[Sans Bateau]

This is the place to get good quality multi strand windlass cable from:

Great supplier

 

[PeterGibbs]

This is what I have on my Bavaria - powered from the main service batteries in the saloon. The cable run is no more than 4.5m with corresponding weight of cable.

I strongly urge not to locate a battery up front - just a nightmare vis a vis servicing, weight distribution etc etc.
You have to have a really special reason to do that, and I don't see such elements in what you describe as your setup here.

PWG

 

[AOWYN]

I am taking advice from the good people at ADVERC BM.
They recommend a 12v to 12v charger, requiring relatively small cable from main battery to bow battery. The cost of the charger is less than the price of the heavy cable which would have been needed to go from the main batteries to the windlass, and the small charging cable is a lot easier to run than two strands of heavy stuff.

Not completed the job yet, but Adverc have not misled me yet.

 

[pvb]

I'm sure Adverc will have told you this, but you need to make sure you install a fuse or breaker at both ends of the wire connecting the two batteries.

 

[RedAdmiral]

Did exactly the same as Vyv about six seasons ago. Low tech but it works and goes on working with no battery problems. Deeply suspicious of unnecessary electronic solutions at sea!!

 

[sailorman]

This is what you want