Windlass wiring

[rochepoint]

The PO has the power for the Lofrans windlass coming from the house bank of batteries (4 6volt golf cart type). The Perkins engine has a D8 for starting. Here is the question, would I be better off suppling the power to the windlass from the D8 starting battery? The reason I ask is when we are using the windlass the high draw of the motor has an effect on lights and electronics that are also running*. Thanks in advance.......

 

[RED]

A couple of thoughts

Ideally, you should have the shortest cable run, to minimize voltage drop. You don't mention which bank is physically closer.

Do you have a generator, or use the alternator to recharge batteries?

The downside of using your starting battery is typically a long cable run (resulting in voltage drop and higher current draw. Also, if you ever try to raise the anchor before starting the engine, you could wind up with a dead starting battery.

 

[rochepoint]

The D8 starting battery would have a shorter cable run. When motoring the alternator looks after charging both banks, the D8 also starts the genset. I always start the engine first. Also I have a solenoid that can combine all banks.

-- Edited by rochepoint on Saturday 9th of January 2010 05:32:09 PM

 

[Capn Chuck]

Our windlass runs off the house bank just as you describe. We have anchor quite a bit and no instruments or anything else is affected by the windlass running. If you are having a problem then something else is wrong. Perhaps the cables to the windlass are too small. Just changing batteries is not going to solve your problem. You need to find out why the lights and instruments are affected. Here is how we set ours up, http://tinyurl.com/yha5ge7 .Chuck

-- Edited by Capn Chuck on Saturday 9th of January 2010 06:04:57 PM

 

[Marin]

Four 6vdc batteries provide more amp hours than a single 8D, so assuming your 6v batteries are up to snuff you would actually be connecting the windlass to less battery power if you connected it to an 8D.

Our boat currently has two 8Ds, one for "house" and the other for "start." We are contemplating replacing the two 8Ds with six 6vdc golf cart batteries on the recommendation of our electrical shop. Each 8D battery box will hold three golf cart batteries. Four of the 8Ds will become our "house" side and the other pair will be the "start" side. According to the shop, this will double our available house amp hours from 200 to 400.

We always start the engines before using the windlass (Lofrans Tigres) and we set the battery selector switch to "ALL" so that both alternators are replenishing both batteries. (When we shut down we immediately switch the selector to "2" which is the 8D we use as our house battery.) But with the engines running, like Chuck we experience no lights flickering or instrument problems when the windlass is operating.

I would suggest having your house bank batteries load tested to find out if they are still capable of meeting their rated power draw.

 

[Brent Hodges]

First, it does sound like you could have a bad connection somewhere. I'd make sure all the battery connections are clean, tight, etc.

However, the starting battery is more the type of battery needed for something like a windlass operation. Start type batteries are good for short burst of high current, where deep cycle, like golf carts, are better for long, lower amperage uses. Since you are likely to have the engine running when you use the windlass your start battery (especially since it is an 8D, which is more than enough for your engine or a windlass) would be a good choice.

By the way, assuming you have about a 20 foot run one way to the windlass, and your windlass is around a 1200 watt, for a 10% voltage drop (reccomended by ABYC) you should have at least #2 wire ran to the windlass. For a 3% drop (reccomended by me) it would take 2/0 wire.

Also make sure you have overcurrent protection (fuse or breaker) and a switch in the windlass wire.

 

[FF]

Most of these tiny windlasses are 1000W , that's only 80 or 90 amps.

If the lights get wonkey ,what happens with the inverter?

I would use the windlass a bunch just on the batt bank and either touch (very carefully) or measure with an IR heat gun the temperature of all the connections in the circuit.

Running on 12v , engine off will raise the amperage , raising the temps , making it easier to find the weak spots.

Good Hunting,

FF

 

[koliver]

We did this before, but here goes:

1000 watts =83 amps
battery bank holds minimum 200 AH,
most of us have 400 AH min.

So you could crank your windlass (200/83 = 2.4 hrs; /2 for margin, 1.2 hrs before depleting your battery.

The Lofrans Tigres (most of us have that or an equivalent windlass) raises the anchor at 1 ft per second (I have timed mine) so raising 200 ft of chain will take 3.3 minutes, using 4.65 AH of power at full pull. the only part of that that will actually use full pull is the one second or so that the anchor is being broken free of the mud. the rest is at a much reduced amp draw, as all that is happening is winding it in. So your actual usage of power will be maybe 25% of these numbers.

All losses in wiring runs and connections ignored.

You won't need to worry about which battery it is connected to, as the draw for a 2 minute pull wont be too much for either one. If you don't have the voltage, you will need the input from an alternator to increase it. That may be the case if you are well stuck in the mud or have hooked onto something real heavy (see my very old post re hauling up a trailer).

 

[FF]

"the only part of that that will actually use full pull is the one second or so that the anchor is being broken free of the mud."

The windlass was never designed for this service , and it is poor seamanship to overload equipment on purpose.

The damage of repeated overloads is overheated wiring and short brush life.

 

[RickB]

FF wrote:

The windlass was never designed for this service , and it is poor seamanship to overload equipment on purpose.

*Operating at full rated load is not overloading, it is working at the design specification.

 

[FF]

"full pull is the one second or so that the anchor is being broken free of the mud."

This is breaking out the anchor is NOT part of the design for rated operation.

The only units that can do this are Hyd (never seen an air windlass) powered where when overloaded they just STOP, and await more pressure .

But they don't suffer any harm while stopped.

The electric stuff requires the CB to pop at just the right time to not let the white smoke out.

Even more frightening are electric bow thrusters , with really short operating limits.

FF