Windlass wiring

[Capedory30262]

Can anyone give me sound advice on ALL wiring for installing a windlass?

[CharlieJ]

Not to be a smart a$$ but: RTFM and then return here with questions to clarify what you don’t understand.

[Capedory30262]

Hi Charlie, I tried contacting your business (phone/email)regarding this to no avail, I'd love to talk personally over the phone. You could say I'm old school, I hate cell phones and CPU's. I have read the manual. I'm trying to decide wether or not to add a battery up in the bow. The question is can I run wire (cable) from my starting battery that's being charged by what I believe to be a 35 amp alternator to keep that bow battery charged? I'll need 30 feet of wire to make the run between the batteries so I think I have to double that (60 feet). What gauge wire? and I'm certain you know running that wire won't be easy so smaller is better. I do have other questions and so glad you chimed in here. Thank you Charlie.
Jack

[SailingHarmonie]

Originally Posted by Capedory30262

Hi Charlie, I tried contacting your business (phone/email)regarding this to no avail, I'd love to talk personally over the phone. You could say I'm old school, I hate cell phones and CPU's. I have read the manual. I'm trying to decide wether or not to add a battery up in the bow. The question is can I run wire (cable) from my starting battery that's being charged by what I believe to be a 35 amp alternator to keep that bow battery charged? I'll need 30 feet of wire to make the run between the batteries so I think I have to double that (60 feet). What gauge wire? and I'm certain you know running that wire won't be easy so smaller is better. I do have other questions and so glad you chimed in here. Thank you Charlie.
Jack

You can run a windlass either way, separate battery or not. From the house, or the starter battery. The number of variables are HUGE, and honestly I could give you an answer, but without a LOT more detail, it is really hard to give one that would be right. And how exactly are we supposed to give you wire size recommendations knowing what you have told us so far??? Sometimes asking for free advice only gets you so far.

For example, on my boat I run a bow thruster that draws 500 Amps from the house battery 30 feet away. I am going to bet you a case of beer that your windlass draws a lot less than that.

We have no idea what windlass, its power draw, what battery, what alternator, what boat, what kind of charging system, etc, etc, etc. There are NO one size fits all answers here.

Designing a system like this takes a lot of time. You should be a bit more humble about asking people for that time for free.

[Capedory30262]

Understanding very well that it takes time and you do this sort of thing for a living is the exact reason I tried contacting you off of this site Charlie. Thank you for your time.

[GordMay]

As Charlie notes, we could offer more detailed guidance, if we knew the exact windlass make & model [specifications].
Consult your windlass manual for the correct wire sizing & configuration, depending on draw, wire length, and motor & control type.

A windlass requires heavy-gauge cable, from the battery to the contactor & motor.
Since voltage drop occurs over wire distance, the longer the wire, the larger wire size needed. This argues for installing a dedicated battery, at the windlass.
However, a dedicated battery adds to the [already appreciable] cost & weight, of the windlass, anchor and rode.

[Island Time O25]

Related question (and may give OP an idea of what info to give)

Boat: 36', displacing 17,000, about 20,000 fully loaded and crewed.
Windlass: Old Nielson H700, drawing about 60amps (I think)
Engine: Universal 5432
Alternator: 110amps
Starting/house bank (combined): 4X27s
Windlass batteries: 2X27s at the bow.
Battery to windlass cable: 2/0 (I think, will check for sure when at the boat but about the width of a pinky finger), app. 5-6' run.
Charging cable run to windlass batteries app. 20-25'.

Questions:
1. What gauge for charging cables?
2. Best point of attaching charging cables on the charging side? i.e. battery bank? Buss? Alternator? Dedicated charge controller? Other?

Tnx in advance.

[CharlieJ]

@Capedory3062 #5: Although there is good info in SailingHarmonie’s #4 response, the last sentence was pretty harsh, which is his style.

I tried contacting your business (phone/email)regarding this to no avail

Website is terribly out of date.

As Gord stated you can power the windlass with either a local battery at the bow or from your starting or house bank further aft.

There are pros/cons for either method.

With the battery in the bow:
> eliminates the requirement for long run of relatively large gauge cable from house or starting batteries to the windlass
> it can be charged either off of the existing charger in the E/R with a long run of appropriately sized conductor to minimize voltage drop or from a dedicated charger in the bow.
> has to be sized properly to support the expected weighing operation or operations as recharging will be slow; e.g., anchor will not set in chosen spot so it must be weighed and you move to another spot and try again. Wash and repeat until the anchor is set. There will be no significant recharging of the windlass battery during these evolutions.

Powering the windlass from the house or engine start battery (assuming they are in the E/R or well aft) has accompanying pros and cons:
> must run large gauge wire from the batteries to the windlass to provide sufficient current with acceptable voltage drop
> consider how your alternator output is routed to the start battery and house bank. Use the battery being charged by the alternator to power the windlass. This is the biggest advantage of this installation: the battery powering the windlass is being recharged during the anchoring evolution

To answer your questions directly:

The question is can I run wire (cable) from my starting battery that's being charged by what I believe to be a 35 amp alternator to keep that bow battery charged?

Yes.

I'll need 30 feet of wire to make the run between the batteries so I think I have to double that (60 feet).

Correct. Current flows from the battery and returns to the battery.

What gauge wire? and I'm certain you know running that wire won't be easy so smaller is better.

I feel your pain regarding running new wire in an old boat!

Wire size on a boat is a function of the current and the allowable or desired maximum voltage drop. It is general practice that critical equipment is provided with current at a max voltage drop of 3% while other equipment (e.g., lighting) can tolerate a 10% voltage drop. There are a lot of tables and apps available to determine wire size for a particular circuit length and current.

For your question: assume that all 35A from the alternator is available to charge the windlass battery and, since a windlass works hard at times, size the wire for <3% voltage drop. Using 105C Boat Cable you will need AWG 2 (35mm^2) to supply the windlass.

Note that this wire will need to have a fuse or breaker to protect it located properly (that is a whole other lecture!).

Although some windlass manufacturers don’t specify it, it is considered best practice to provide power to the control station/foot switch via a second circuit usually supplied from a circuit breaker on the panelboard.

[sealandsky]

Do you have a bow thruster? If so, do you have a dedicated battery(s) for it? If you do have a bow thruster and do not have a dedicated battery for it and at the same time are trying to better your windlass situation, then I think we have stumbled on the answer! In my case i recently installed a 28V bow thruster and am powering it from 2 12V Group 31 batteries located 5 feet from the thruster. Now this year I"m installing a new windlass (Maxwell RC12 HD) which is also 28 volts. Since I cannot imagine a situation where I'd need to run both at the same time, I'm powering the windlass off the 28V bow thruster batteries and that cable run is only around 16 feet. The old windlass that I'm removing was powered off a 12V buss in the engine room and had a run of around 30 feet.