Windlass on Engine Battery?

[ylop]

Whilst troubleshooting something today I discovered that my windlass (not factory installed, but there before I owned the boat), is wired to the engine battery not the house battery.

Whilst it’s unusual for us to use the windlass without the engine running and it would take a fair chunk of windlass use to seriously impact the engine start battery it struck me as a bit odd. To me the engine battery is normally sacrosanct and everything else is on the much larger house batteries. They are connected via a diode as per the Bavaria factory, and the house batteries have a solar panel. I do have the ability to “jump” them on board.

So other than saving 12” of cable is there any logical reason to have them this way? And would you change it? Currently there is no windlass “switch” on the control panel (well there is a switch but it’s not wired to anything) and the windlass just goes through a 100A dedicated “breaker” / “trip” switch which is in an awkward position. I’m considering fitting a relay so it can easily control from the nav desk rather than moving cushions and rummaging blind upside down!

Any thoughts?

 

[William_H]

I would think it desirable to run anchor windlass from the engine battery not the house battery. On the basis that with engine running and alternator charging the alternator can feed more directly current to the windlass. Albeit with battery contributing. To take from house battery would see alternator contribution coming via your house battery charging device. If indeed that is via diodes then alternator contribution would still be via a diode. (not desirable to my mind)
In the end perhaps OP should not fret but stay with what works. ol'will

 

[garymalmgren]

Currently there is no windlass “switch” on the control panel (well there is a switch but it’s not wired to anything) and the windlass just goes through a 100A dedicated “breaker”

Does this mean that your windlass only goes one way?
How do you activate the windlass is there is no switch?

 

[ChromeDome]

When I got my boat, the windlass was connected to the house battery bank, in the back of the boat. Long, fat cables, but when the windlass was used it took the juice from the radio and other electronics.

I kept the existing cables but inserted a separate battery near the windlass motor. A powerful relay isolates this battery from the rest of the boat the split second the switch is activated and due to the small delay, the other consumers do not realise that the big power thief is running.

As soon as the switch is released, the circuit returns to normal and the battery is charged along with the battery bank

It cost a battery, a relay and some wiring and it works 100%.

 

[NormanS]

My engine start battery is reserved for starting the engine, nothing else. Admittedly, the engine is often started before lifting the anchor, but by no means always. In suitable situations there is nothing better than sailing away from anchor, and not using the engine at all. But I wouldn't lose any sleep over having the windlass powered from the engine battery, particularly if you usually start the engine before lifting the anchor.

 

[Tranona]

That is quite common, but usually has an interlock switch wired in so that you can't use the windlass without the engine running. windlasses are like engine starters - short periods of high current followed by no use and battery recharged by engine. If the engine is running at say 1500rpm there is probably no drain on the battery.

 

[mikegunn]

It’s not unusual for engine start batteries to be also used for powering a windless. In such instances it is also usual to insert a high current relay in the feed to the windless, which in turn is only energised when the engine is running. Thus minimising the chance of inadvertent battery drain.
Mike

 

[ylop]

Currently there is no windlass “switch” on the control panel (well there is a switch but it’s not wired to anything) and the windlass just goes through a 100A dedicated “breaker”

Does this mean that your windlass only goes one way?
How do you activate the windlass is there is no switch?

No. Sorry I didn’t explain that very well. There is a box at the bow with a handset with up down buttons. But Bavaria have a switch on the control panel labelled for the windlass so I assume their factory fitted ones have a big relay switched by this ordinary switch (with led).

 

[Roberto]

it is also usual to insert a high current relay in the feed to the windless, which in turn is only energised when the engine is running. Thus minimising the chance of inadvertent battery drain.

I would personally leave that setup as precautionary for charter boats, or sailed by several casual people not all aware of the electric system; when on one's own boat I think it s the first thing that comes to mind, on the other hand it may be nice to be able to use the windlass for short periods without having to start the engine, say to modify a little the tension on a rode, a mooring line, etc.

 

[pretzel_logic]

I would have thought that it's because of the types of batteries used. Engine batteries have a lot of thin plates to deliver a large current, but not for long periods (engine, windless), whereas service batteries have thick plates to deliver a more constant lower current but for long periods.

 

[PaulRainbow]

No. Sorry I didn’t explain that very well. There is a box at the bow with a handset with up down buttons. But Bavaria have a switch on the control panel labelled for the windlass so I assume their factory fitted ones have a big relay switched by this ordinary switch (with led).

I don't think so (but may be mistaken), it's common to switch the control supply, rather than the main battery cables.

I would leave the windlass on the engine battery, that's how most/all French production boats are wired, albeit with a relay that prevents it from being used if the engine is not running. I don't like that system, what happens if the engine won't start and you want to raise the anchor and sail home, for instance.

a) The alternator gives the battery a helping hand.
b) There is no chance of a voltage drop upsetting delicate electronics.

 

[PCUK]

On every boat I have built or restored the windlass has always been connected to the engine battery as my preference.

 

[vas]

+1 on what Paul said above.
The cables/switch is tiny, just providing the juice to "close" the circuit and run the big relay that engages the up or down.
Often bypassed by "stealing" voltage from the main power cable arriving to the relay ;-)
I ALWAYS use this switch to disable inadvertent use of the windlass (as in shorted foot or toggle switch resulting in lifing all anchor when boat unattended and coming back to see the boat missing (or worse in the beach - has happened more than a few times!)

V.

 

[Neeves]

There are purists who sail to their location of anchoring, works well in an empty bay, a bit stress full if its busy.

Its the 21st Century - you have an auxiliary motor to reduce stress.

I'd want windlass connected to engine battery, as we always had the engine running when using the windlass. When you retrieve the rode or deploy the rode it is wise to have the engine running, anyway, to allow you instantaneous ability to manoeuvre the vessel. I cannot think of any reason, except no fuel, not to run the engine (you don't need to use it - its there )

If you are safely anchored and you want to change - if you simply want to deploy more rode you can release the clutch, if its more serious you will have the engine running.

I cannot think of any reason to connect the windlass to the house bank - but I would want the ability to switch the house bank to the engine battery or switch the engine battery to the house bank.

Jonathan

 

[ylop]

I don't think so (but may be mistaken), it's common to switch the control supply, rather than the main battery cables.

Ah perhaps - especially if the motor control relays are mounted at the nav station. Mine are in the forward most locker of the forward cabin - so shortest distance from there to the windlass but a long length of “always live” cable feeding into this.

There’s actually an LED light that’s “borrowed” the power from these fittings. The power cables don’t go through the main power isolator switch/bus bar so if that light is left on it is actually draining the engine battery - albeit very slowly. My expectation that turning off the main isolator turned everything non essential off has proven wrong.

I would leave the windlass on the engine battery, that's how most/all French production boats are wired, albeit with a relay that prevents it from being used if the engine is not running. I don't like that system, what happens if the engine won't start and you want to raise the anchor and sail home, for instance.

I agree being dependent on the engine does seem odd (although our normal procedure would be to have the engine running as a get out of jail card anyway - and so we know it’s all working in case needed later (I don’t want to discover a flat battery or dodgy switch at a critical moment if I could have sorted it whilst in anchor earlier in the day).

Do they wire them so the engine has to be actually running or just so the switch needs to be “on”.

We can always revert to manual on the windlass if there is no power.

a) The alternator gives the battery a helping hand.
b) There is no chance of a voltage drop upsetting delicate electronics.

Ok I can see why people might prefer to wire them this way - although I wonder if with 80Ah engine battery 300Ah house batteries if that difference would be real - I’ve very heard the engine note change when using the windlass and it is mostly used on tickover. The engine battery is a leisure battery rather than an actual starter battery in line with Volvos guidance so the different plate thickness will make no difference.

However I’m happy to make minimal changes… I’ll focus on the parasitic LED light instead…

 

[NormanS]

I'm certainly not a purist, but I do enjoy being able the anchor and raise anchor without starting the engine. I have a boat with sails. When I started sailing, yacht auxiliaries were very unreliable, and couldn't be relied on to start, so we had to be able to do things under sail. I get the impression that a lot of modern yachts have powerful engines, with auxiliary sails. Not that I'm criticising, everyone is entitled to their own preferences.

 

[vas]

not a purist by any stretch owning a twin turbodiesel mobo, but leaving an quiet anchorage early in the morning with no wind and a couple of ropes to the rocks/trees on the beach I'm happy to let the nearby boat occupants sleep in peace, swim out, remove ropes, pull anchor in slow bursts (usually 60odd metres) and once away from other boats, fire up the engines and leave (at idle speed...) 1800W windlass on service bank but twin engined/twin alternators means one charges engine bank, other charges service, so no chance of running out of juice.

 

[PaulRainbow]

Ah perhaps - especially if the motor control relays are mounted at the nav station. Mine are in the forward most locker of the forward cabin - so shortest distance from there to the windlass but a long length of “always live” cable feeding into this.

It's normal to have the contractors (relays) close to the windlass. The supply cables would be isolated by turning the engine isolator off and should have a thermal circuit breaker close to the supply end.

There’s actually an LED light that’s “borrowed” the power from these fittings. The power cables don’t go through the main power isolator switch/bus bar so if that light is left on it is actually draining the engine battery - albeit very slowly. My expectation that turning off the main isolator turned everything non essential off has proven wrong.

I would definitely change that. Positive cable sound come from the isolator or busbar, to a thermal breaker, then to the windlass. Obviously ensuring that the isolator or busbar is rated for the windlass current.

I agree being dependent on the engine does seem odd (although our normal procedure would be to have the engine running as a get out of jail card anyway - and so we know it’s all working in case needed later (I don’t want to discover a flat battery or dodgy switch at a critical moment if I could have sorted it whilst in anchor earlier in the day).

Do they wire them so the engine has to be actually running or just so the switch needs to be “on”.

The ones i've seen, the engine has to be running.

We can always revert to manual on the windlass if there is no power.

Ok I can see why people might prefer to wire them this way - although I wonder if with 80Ah engine battery 300Ah house batteries if that difference would be real - I’ve very heard the engine note change when using the windlass and it is mostly used on tickover. The engine battery is a leisure battery rather than an actual starter battery in line with Volvos guidance so the different plate thickness will make no difference.

However I’m happy to make minimal changes… I’ll focus on the parasitic LED light instead…

The switch on the panel would be for the control circuit (foot switches, wired/wireless remotes etc) A wire would be taken from the switch, or possibly in the loom somewhere, they may well have a wire forward in case a windlass was spec'd. Modern Bavarias tend to have a one size fits all wiring harness, suitable for whatever options are chosen. This wire would supply +VE to all of the switches/remotes, which in turn trigger the contactors. The purpose of the switch/LED is to isolate the windlass controls when not in use so that accidental activation cannot happen, as Vas details above. Would be worth looking at the wiring schematic for the boat and see if it's easy enough to wire this as it should be.

 

[ylop]

I would definitely change that. Positive cable sound come from the isolator or busbar, to a thermal breaker, then to the windlass. Obviously ensuring that the isolator or busbar is rated for the windlass current.

There’s an isolator in the positive - but direct from battery to isolator then to the front of the boat. The negative returns from the bow direct to the battery negative. All the other electrics (except the radio) go back to a massive negative bus bar which it then has the isolator between the bus bar and the battery. Bavarias always seem to have the master switch in the negative rather than the positive - not sure why but I’m not going to change that.

 

[Tranona]

There’s an isolator in the positive - but direct from battery to isolator then to the front of the boat. The negative returns from the bow direct to the battery negative. All the other electrics (except the radio) go back to a massive negative bus bar which it then has the isolator between the bus bar and the battery. Bavarias always seem to have the master switch in the negative rather than the positive - not sure why but I’m not going to change that.

Bavaria changed to the more normal isolator in the positive in the late noughties. I converted my 2001 37 by doing away with the split diode and fitted a BEP Marine switch cluster with a VSR, amazon.co.uk/BEP-Horizontal-Battery-Distribution-Cluster/dp/B0185C8CHW and left the -ve isolator closed with key removed