Powering a windlass - Thoughts

[evm1024]

Originally Posted by Adelie

You forgot the 5th way:
Hands, arms and back.

I did forget it. Mike OReilly reminded me of my blind spot a few posts back. I really did forget it and welcome the correction.

[BlackHeron]

Originally Posted by Pizzazz

The best solution is to install the batteries midship. Even on a 50 ft boat, the windlass is 3-4 ft from the bow, the engine is 15 ft from the stern, if the batteries are halfway between the engine (starter) and the windlass), the distance is 15-20 ft. For each. Not so bad.

SVHarmonie summed it up nicely. Most of the time, the battery voltage drop will be much bigger than the cable drop. Just measure it and address the offending issue. For boats > 45 ft you should consider going to a 24V system for windlass, bow thruster and starter/alternator.

Agreed 100%

A central battery bank, also closer to DC branch circuit panel. Don't forget that voltage drop to accessories on the branch circuit runs are additive to that of the voltage drop of the panel main feeder cables with typical loads and possible.max loads with everything on at once.

Run larger individual cables, install them into a flexible conduit to protect them, tap them down to smaller cable those last couple of feet if need be for ease of connection or fishing up to the windlass or circuit panels.. A couple feet of #1 or #2 isn't going to kill the voltage drop equation in all but the biggest windlass motors, while those often have accomodations for decent-sized feeder cables anyhow. And for the love of all that is holy use a properly-sized fuse or breaker to protect the wire between the battery area as well as the motor and other loads, especially on the branch circuit panel feeders.

The same goes for the wires to the engine. Don't cheap out. Starter motors don't like voltage drop either and it reduces their lifespan and hurts cranking power considerably. If your diesel doesn't just crank over fast like your car or truck then it probably could use larger cables. If it is struggling when the batteries are full, it'll be even worse when they are down a bit.

Voltage drop also reduces charging efficiency on those fancy oversized alternators. I've seen alternators running 10+ feet to the batteries on ridiculously undersized wire. The worst was a boat I worked on with #10 wire between the alternator and the batteries. Running big cable between the engine alternator and the batteries may yield as much of an increase in charging as a bigger alternator upgrade. Resistance = heat (I-squared R losses). And heat causes more resistance and also causes the alternator to kick down to protect itself from that heat.

Putting the battery bank in a central location helps keep all cable runs shorter, with less voltage drop.

[CarinaPDX]

#2 (battery with small cable) is a no-go: under load the windlass will draw a lot of amps, which as others have noted will pull down the battery voltage. This in turn will pull many of those amps from the house batteries and/or alternator, and that "small" cable better be rated for all of those amps. #4 is the right way to do this, because the DC-DC charger will be sized for the cable (or vice versa).

Running heavy cable forward is less costly in the long run than running a smaller cable to a DC-DC charger and battery. Yes, it is a nuisance to run battery cable more than half the length of the boat but that is a one time affair. Once installed #1 is the simplest and most robust answer. Personally I think it is silly to haul around a separate battery just for anchoring: a large enough battery to provide adequate amps will likely not be discharged much in use.

The DC motors in windlasses are similar to, and often the same as, starting motors. They are not designed for continuous use (remember the warnings to limit the cranking time?). They are also not intended to pull the boat forward to the anchor: always drive the boat forward towards the anchor with the engine and pull the slack chain up with the windlass. Over-use and over-loading of the windlass is the usual cause of motor burnout.

#5, manual windlass or no windlass, for a 50' boat - this is a joke, right? Yes it is possible with a good manual windlass, but not hand-over-hand unless one is a body-builder on steroids for the heavy gear required. And you better not be single-handing: when the anchor is off the bottom the boat is moving, and running between the bow and the steering station to bring the anchor up and keeping minimal control is a fire drill. I started out cruising with a beautiful bronze R.C. Plath windlass. Bringing in anchor chain in the tropics with 3" recovered each direction required taking breaks and re-hydrating, and if there was wind it was downright terrifying running fore and aft - and this on a (heavy) 31' boat. Don't even think about it...

Greg

[evm1024]

Greg, Thanks for the observations.

What you say regarding type 2 is true for a plain battery combiner relay. With load on the remote battery causing a voltage drop the draw on the small cable from the house bank will likely exceed the ampacity of the cable and that is not good (tm).

However, an echo charge or other such device will be current limited to the devices rating (and of course you would size the small cable to match those needs). Thus some of the needed current would be supplied safely from the house bank.

For those who make the choice based on the long run costs type 1 would as you say be a very likely choice. In matters of taste there is only opinion.

Plus battery technology is rapidly moving forward. The test case batteries (LiFePO4, 32 Ah) I have are designed for high current applications. They are capable of delivering 150 amps for 10 minutes without breaking a sweat. I can't guess whet the dead short current is even tough the wrench in the video is limiting the current to 120 some amps. They fit into a 7 x 7 x 6 priority mail box with space left over. Just an example here:

https://www.youtube.com/watch?v=tMUBBAiFX6c

As for the 50' boat joke. No not a joke. What I think happened was that because I have a 50' boat it got projected that this was for my boat rather than a general look at options for powering a windlass or thruster. Easy how assumptions creep into the discussion.

[Mike OReilly]

Originally Posted by Adelie

You forgot the 5th way:
Hands, arms and back.

HA! Beat ya to it .

Originally Posted by CarinaPDX

#5, manual windlass or no windlass, for a 50' boat - this is a joke, right? Yes it is possible with a good manual windlass, but not hand-over-hand unless one is a body-builder on steroids for the heavy gear required. And you better not be single-handing: when the anchor is off the bottom the boat is moving, and running between the bow and the steering station to bring the anchor up and keeping minimal control is a fire drill. I started out cruising with a beautiful bronze R.C. Plath windlass. Bringing in anchor chain in the tropics with 3" recovered each direction required taking breaks and re-hydrating, and if there was wind it was downright terrifying running fore and aft - and this on a (heavy) 31' boat. Don't even think about it...

Certainly a manual windlass would work, but I agree, it is more difficult with a solo crew than a two or more crew. But everything is more difficult. And funny, my windlass for the past decade has been a Plath (beautiful) bronze . Has always worked great, in all conditions.

[CarinaPDX]

Originally Posted by evm1024

What you say regarding type 2 is true for a plain battery combiner relay. With load on the remote battery causing a voltage drop the draw on the small cable from the house bank will likely exceed the ampacity of the cable and that is not good (tm).

However, an echo charge or other such device will be current limited to the devices rating (and of course you would size the small cable to match those needs). Thus some of the needed current would be supplied safely from the house bank.

I put the echo charger in class #4.

As for the 50' boat joke. No not a joke. What I think happened was that because I have a 50' boat it got projected that this was for my boat rather than a general look at options for powering a windlass or thruster. Easy how assumptions creep into the discussion.

When you don't state otherwise it is normal to assume you are talking about your own boat, in this case a 50'. When starting threads it is important to say what boat you are talking about - answers may differ with the boat - and failing that you should expect the assumption.

Greg

[CarinaPDX]

Originally Posted by Mike OReilly

And funny, my windlass for the past decade has been a Plath (beautiful) bronze . Has always worked great, in all conditions.

Plath was a local Portland company. I ordered and picked it up at the factory, and got the polished model (extra cost over the rough sand casting surface). It was simple and robust, but pulling 3" in each direction is just too slow for me. My ultimate decision to switch was the result of the fire drill I did raising the anchor while trying to keep clear of other vessels - not a problem for couples. Still, having a power windlass with a chain counter display and up/down controls in the cockpit has made a world of difference, even with crew.

Greg

[Mike OReilly]

Originally Posted by CarinaPDX

Plath was a local Portland company. I ordered and picked it up at the factory, and got the polished model (extra cost over the rough sand casting surface). It was simple and robust, but pulling 3" in each direction is just too slow for me. My ultimate decision to switch was the result of the fire drill I did raising the anchor while trying to keep clear of other vessels - not a problem for couples. Still, having a power windlass with a chain counter display and up/down controls in the cockpit has made a world of difference, even with crew.

That explains how this windlass ended up on my boat. Mine was built by a west-coast based company (although constructed in Taiwan, along with many similar boats of this vintage). As far as I can tell my Plath is original equipment, making it 43 year old this year. Keeps on tickin' with almost zero problems (I've had to replace the handle).

And yeah, it moves about 3" per push/pull. Since it takes about a second to do this, it moves about a foot in about four seconds. So, hauling in 160 feet takes about 11 minutes. And sure, it's harder to pump a handle than push a button, but seriously ... it's not that hard. It's like saying a manual winch (which most of us still have) is harder than an electric. Sure it is, but a properly sized winch (or windlass) means the effort is not that hard. That's the point of a winch.

[Jammer]

Originally Posted by evm1024

--------------------------Here we go -------------------------

1) Heavy Cable
2)Remote Battery small cable
3) Remote Battery Remote Mains Charger
4) Remote Battery DC to DC Charger

5) Set your boat up for 24v so you can use ordinary 6 gauge duplex boat wire to the windlass without voltage drop being a problem, among many other reductions in wire size

Originally Posted by triibutu

I am interested to learn, how reduced voltage causes a dc motor to overheat?

It doesn't, of course, but you knew that.

[MJH]

Originally Posted by evm1024

I blocked this out about a year ago and never got around to posting it. Sitting at home and I dusted it off after reading in another thread.

I've divided ways of powering a windlass into 4 basic types and list a few pro's and con's.

I am using type 3 on my boat currently. I have most of the parts to try out type 4 using some Headway LiFePO4 cells (16 cells for 32 AH@13.2 volts).

--------------------------Here we go -------------------------

1) Heavy Cable

Advantages to running heavy cable (2/0, 4/0) include “unlimited
runtime, no extra technology and pretty much zero maintenance. Tried and true.

Disadvantages include the cost and weight of the cable, 10% or more voltage drop.

2)Remote Battery small cable

Advantages include essentially no voltage drop due to the short cable run to the windlass. The small gauge charging cable is easy to run from the charge source to the battery. The “echo charge” or combiner can be located at the windlass battery. In a pinch the windlass battery can be disconnected and used as a start battery.

Disadvantages include runtime limited to that of the windlass battery. Given the small gauge of the charge cable there is a potential for long recharge times. The charging system and the windlass battery must be of compatible technology, typically the same technology. A largish remote battery implies weight, the potential for fumes if FLA and such.

3) Remote Battery Remote Mains Charger

Advantages include essentially no voltage drop to the thruster due to the short cable length. With a remote charger running off the mains voltage you can have the battery technology and voltage of your choice for the windlass. That is to say you can put a 24 volt windlass in an otherwise 12 volt boat.

Disadvantages are an increase in complexity – you need to be running the inverter to run the charger that charges the windless battery. Runtime is limited to the remote batteries capacity and charge time is determined by the charger rating and of course the inverter capabilities. Overall efficiency is around 80%.

4) Remote Battery DC to DC Charger

Advantages include essentially no voltage drop to the windlass as well as a small gauge charge cable. Using a DC to DC charger you can have a different windlass battery voltage and chemistry from your house bank. You could run a 24 volt LiFePO4 windlass battery in a 12 volt lead acid boat.

Disadvantages include runtime limited by the battery capacity, more complexity and log charge times. Interestingly the overall efficiency is around 87% which is comparable to running heavy cable.

I went with your option #1 ten years ago and have never had a problem or been sorry. Don't kid yourself, KISS (keep it simple stupid) has a lot going for it and who needs another battery to take care of.

~ ~ _/) ~ ~ MJH

[evm1024]

Originally Posted by CarinaPDX

I put the echo charger in class #4.

Greg

You missed the point of type 4. The major feature of type 4 is its independent charging capability without regard of the voltage that powers the DC to DC charger and the possibility of voltage conversion that a dc to dc charger provides. Think along the lines of a Victron Orion-Tr Smart 12/12-30A Isolated DC-DC Charger and its brethern.

When you don't state otherwise it is normal to assume you are talking about your own boat, in this case a 50'. When starting threads it is important to say what boat you are talking about - answers may differ with the boat - and failing that you should expect the assumption.

Actually, if you look at the title of the thread you will note that I did not include any reference to the size of boat. Also, you will note that in the description of each type there was no reference to boat size, windlass size or any size. In fact it was quite general.

I did state that I was using a type 3 on my boat and that I was thinking of trying out a type 4 on my boat.

I don't think that there is any such forum rule that requires this of the OP. And if there were I likely would not follow them. Just as there is no rule that requires a reader to assume.

I think that it is a bit presumptuous to assume that I was asking for advise. Rather I thought it was clear that I was presenting 4 options for powering a windlass with the thought that CF members could discuss the merits of each. It appears to me that the majority are doing just that.

But let me clarify - I'm not talking about a specific boat. I'm posting about 4 ways of powering a windlass and the trade offs (pro or con) for each.

[tankersteve]

I totally respect #1, especially over time.

At what point does a boat get so large that a hydraulic system becomes relevant? For perhaps multiple uses, such as anchor windlass, bow thruster, furler, winches, davits, etc...

Tankersteve

[evm1024]

Originally Posted by tankersteve

I totally respect #1, especially over time.

At what point does a boat get so large that a hydraulic system becomes relevant? For perhaps multiple uses, such as anchor windlass, bow thruster, furler, winches, davits, etc...

Tankersteve

Yes, good question.

So we should place a manual windlass as type 0 and a hydraulic powered system as type 5.

Or move them up (type 1 becomes type 2)

[rslifkin]

Originally Posted by tankersteve

I totally respect #1, especially over time.

At what point does a boat get so large that a hydraulic system becomes relevant? For perhaps multiple uses, such as anchor windlass, bow thruster, furler, winches, davits, etc...

Tankersteve

I was thinking that as well. By the time you're likely to have a high enough powered windlass for cabling to be unmanageable even at 24 volts and also have a big enough windlass bank for separate batteries to give good performance, you're probably pushing the point where hydraulic makes sense, as you may want / need it for other things anyway.

[ericoh88]

My 12v windlass draws about 150 amps which I can run the fella for 2 minutes - no problem. The 12v bow thruster draws about 550 amps!!! Only 15 seconds and the unit get HOT.

I have 2 trojan gel 225ah in the bow to handle the power draw with 2/0.

Eric