Windlass vs Aging Batteries Question

[Kenomac]

Our Lewmar vertical windlass seems to be getting weaker and weaker. I've already cleaned the electrical contacts which didn't make any difference in performance. The windlass gets routine service once per season.

Our Trojan 450 amp wet cell battery bank is due for replacement, since it now has a maximum capcity of a diminished 377 amps and the diminished capacity can only be charged up to 72% or 277amps while at anchor.

My question: Is the weakness we notice in the windlass due to the damaged batteries? The Yanmar engine runs at idle while we take up the anchor, but due to it's low revs at the time, the alternator contributes very little to the available power for the windlass.

Or... Does the windlass motor need to be rebuilt?

Cheers

Ken

[Cheechako]

Any idea what kind of voltage drop you see while using the windlass? Those motors do pull the volts down quite a bit. I'm betting batteries.

[Kenomac]

I have a voltmeter, can you tell me how I'd go about measuring that?

The windlass is hauling up 12mm chain with a 45kg (99 pound) anchor usually from a depth of 15 meters (45ft).

Thanks

[TacomaSailor]

??? Maybe I am missing something in the OP but the following makes no sense

" The Yanmar engine runs at idle while we take up the anchor, but due to it's low revs at the time, the alternator contributes very little to the available power for the windlass."

Isn't the obvious answer to run the Yanmar at 1800 RPM to get maximum amps (if it is belted like mine) output from the alternator, through the batteries and cables, to the windlass?

Why would you not have the Yanmar running at max electrical output?

[Cheechako]

Originally Posted by Kenomac

I have a voltmeter, can you tell me how I'd go about measuring that?

The windlass is hauling up 12mm chain with a 45kg (99 pound) anchor usually from a depth of 15 meters (45ft).

Thanks

I was just thinking connect the voltmeter to the battery bank and have someone observe it when you run the windlass under load. You could also do this connecting it at the windlass terminals I suppose to see how much more drop there is up there.

[Kenomac]

Originally Posted by TacomaSailor

??? Maybe I am missing something in the OP but the following makes no sense

" The Yanmar engine runs at idle while we take up the anchor, but due to it's low revs at the time, the alternator contributes very little to the available power for the windlass."

Isn't the obvious answer to run the Yanmar at 1800 RPM to get maximum amps (if it is belted like mine) output from the alternator, through the batteries and cables, to the windlass?

Why would you not have the Yanmar running at max electrical output?

Because we are motoring slowly forward as we take up the anchor chain.

[model 10]

You would measure the voltage at the motor. I believe most modern windlasses are permanent magnet motors. They require a higher voltage than the older style dc motors with brushes. Can't remember exactly but the older style would see under 10 volts and the newer style permanent motors need 11+. You should also be able to feel more heat if the motor is running on low volts too.

[skipmac]

First, I assume you have checked terminals and connections for corrosion, tightness, etc?

If it's easy to do I would start with measuring the voltage at the windlass while under load then follow up measuring voltage at the battery under the same conditions.

The first will identify voltage drop as the problem, the second will confirm that you aren't dropping voltage on the cable for some reason.

What's the voltage at the battery with the engine running? Alternator capacity? Does the windlass run better with the engine running or is it about the same as with the engine off?

[Kenomac]

Originally Posted by skipmac

First, I assume you have checked terminals and connections for corrosion, tightness, etc?

If it's easy to do I would start with measuring the voltage at the windlass while under load then follow up measuring voltage at the battery under the same conditions.

The first will identify voltage drop as the problem, the second will confirm that you aren't dropping voltage on the cable for some reason.

What's the voltage at the battery with the engine running? Alternator capacity? Does the windlass run better with the engine running or is it about the same as with the engine off?

We're in a relatively calm anchorage tonight, so in the morning I'll rev the engine higher while remaining in neutral whilst I take up the anchor without engine assist and see if there's a difference. I may try it instead with the genset running.

[TacomaSailor]

Originally Posted by Kenomac

Because we are motoring slowly forward as we take up the anchor chain.

I guess I do things a little differently?

BEFORE I start hauling with the windlass I use the Yanmar/propeller to get the boat moving slowly toward the anchor. I then put the transmission in Neutral and increase the RPM to 1800. I then use the windlass to haul the chain as needed. There is very little load on the windlass because it is only hauling chain and maintaining the momentum of the boat.

Once the boat has forward momentum the windlass load will be negligible until directly over the anchor. At that point you should NOT be using the windlass to break loose the anchor.

Once over the anchor (with chain straight down) I use the chain stopper to take the load off the windlass. I then engage the transmission to slowly move the boat forward/backward to break loose the anchor.

Once the anchor is free the windlass can easily haul up 99 pounds of chain with very little need for higher currents.

Maybe my ideas won't work for you. I do know that I've hauled anchor over 1,000 times while single handing and it is a rare occurrence to have high amp loads on the windlass for more than a few seconds.

66 pound Spade and 300' of 5/16" chain
FX 55 and another 300' of chain

If you are concerned about windlass electrical loads try the following:

- attach recording DVM (Fluke or similar) to +/- windlass terminals
- pull chain & anchor in normal fashion
- check DVM for lowest voltage

- Attach recording clamp on amp meter around one wire connected to windlass terminal
- pull chain & anchor in normal fashion
- check amp meter for highest current flow

[Kenomac]

Thanks for your thoughtful input, I'll try your method tomorrow.

BUT... Here in the Med it's not unusual to be hauling up the chain with a 15-20 knot wind in your face. What to do in this case when I'm by myself? Usually, I just motor forward with enough momentum to haul in the chain, otherwise I end up way on front of the anchor and chain due to the slow windlass speed. When directly over the anchor, I allow the wave action 30 seconds or so to break the anchor free, works every time.

[chala]

Originally Posted by Kenomac

The windlass gets routine service once per season.

Are you sure that the windlass is not in need of grease? I definitely grease mine more than once per season. In fact once before a heavy haul. A grease nipple make the job easier.

[Kenomac]

Originally Posted by chala

Are you sure that the windlass is not in need of grease? I definitely grease mine more than once per season. In fact once before a heavy haul. A grease nipple make the job easier.

I will check in the morning to see if it has a grease fitting. Thank you for the suggestion.

[UNCIVILIZED]

I can’t see the batteries being a problem. But in order to make sure, you could take a fully charged battery up to where the windlass is, & connect it with a short set of cables. Then try lifting X lbs for a short period of time, & compare the windlass’s performance then vs. doing the same test with the normal electrical hookup, including the engine running at your standard retrieval speed.

BTW, how dry do your windlass's electrical components & cables stay? And how old are they? As I'm just wondering if you might have some corrosion creeping down them, particularly if they've been exposed to a lot of dampness. Ditto on the wiring in the windlass itself.

[GILow]

Sluggish performance from our windlass was the first sign that our battery bank had failed.

Simple test is to observe the battery bank voltage at the batteries themselves when the windlass is in operation. (Tricky when short handed). I keep an old fashioned needle type multimeter for just these sorts of jobs because the refresh speed on the digital multimeter is often too slow to spot the problem.

If there was no significant voltage drop at the battery bank then I would start looking at voltage at the windlass itself when operating. The point being, checking the windlass end first proves nothing because a low voltage reading could indicate a wiring fault or it could indicate dead batteries. Smart move is to eliminate the batteries from the equation first.

No apparent voltage problems at either end, then I'd go looking at the brush pack and commutator.


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