windlass wiring thoughts

[rochesterdriver]

So the windlass draws up to 200a at 12v.

I'm thinking there are two ways to go here.

1. Put s 12v deep cycle battery forward under the vberth and charge from the usual system. This keeps the 'load' wiring smaller cause the battery is close by.

2. Use the house batteries, mounted in the engine room area, and put up with VERY large gauge wire running aft to the batteries.

With #1 I'll have to run some wires forward to charge that battery that lives under the vberth. Yes, it will be vented. That will also tie the battery for the windlass to the house batteries by virtue of the 'charging' wires.

With #2 I'll just bite the bullet and run the large gauge wire from the house batteries to the windlass.

Just looking for ideas here folks, thoughts?

Thanks,

Rich.

 

[FourPoints]

Go with opt 1, and it will also improve your house bank size unless you are drawing more amperage than the "charging" wires can supply.

Alternatively add an echor charger onto the house bank, and install a large start battery for the windless.

 

[Steve Dion]

I would agree with going with a dedicated battery forward. Your charger may already have the option for a third bank. You may also want to ask about adding a device to add some charging override from the alternator so the battery can be charged while using the windlass.

If you run wire from your existing battery bank to the windlass you will probably spend several hundred dollars on the wire alone.

 

[Maine Sail]

In theory adding a second bank up forward seems good on the surface but it is rarely less costly. In some situations it can be necessary but in many it is not. What model windlass is it? 200A seems like a very high draw for a 30 footers windlass.

Keep in mind that if you have a 100A alternator your wire gauge will still be very large to get from one eng of the boat to the other and trying to keep voltage drop to a minimum. Voltage drop for charging is more critical than it is for a windlass motor. You also need some hefty cables for the shore charger too. You may even need to add a way to direct charge to this bank as well.

If it can be done running new wires from the house bank is very often less expensive and much more simple to do. For windlass batteries you want deep cycle batts not thin plate starting batteries. Starting batteries don't do well with much more than a few seconds of high load and windlasses can often run for 5 minutes or more per anchoring depending upon how many sets it takes and all this will be at about at 30-140 +/- amps depending upon the model.

 

[Bill Roosa]

Other thoughts
If you insist on not running your engine when you run the windlass you need to supply ALL the electrical power with a deep cycle bat as MS indicated. I never seem to do it that way and Hunter has my windlass tied to the starter battery. Seems that the alternator will hold up the voltage and supply the majority of the current if the engine is running. Mine always is when I weigh anchor.
This solved the problem of running the cables the full length of the boat as my start bat is under the companionway sole.
Your windlass can tolerate a much lower voltage (aka larger voltage drop) so you can get by with smaller cables. Mine are 0000 I believe. You only see max current when the windlass stalls so you are almost never going to see that and when you do you are going to have to consider other means in any case as if the windlass can't pull it there is something seriously wrong (anchor fouled?!). I agree with MS that 200 amps seems like a large value for that size boat. Better to install a large fuse to protect the (smaller) wiring in the event of windlass stall and design for something in the 75 amp range IMHO

 

[Bill1565]

So the windlass draws up to 200a at 12v.

I'm thinking there are two ways to go here.



Just looking for ideas here folks, thoughts?

Thanks,

Rich.

We chose to add to our house bank with batteries under the v-berth. two additional golf carts raise us from 400+ ah to 600+. But then it depends on how you use your boat. When cruising, we sometimes stay in an anchorage for 4-5 days.

 

[rochesterdriver]

What GREAT replies and I thank you all, truly.

The fusing is 200A so the draw will be considerably less of course but I had to have a starting figure. I won't know the true draw until I actually load the windlass.

It is an older Powerwinch 835. It's hell for stout so that helps.

It appears I shall go with cabling aft to the house batteries to run the windlass. As stated, a voltage drop to the windlass is more acceptable than voltage drop for charging any battery.

Gentlemen, many thanks as always. I'd love to see this discussion continued as many will benefit from the information herein.

Rich.

 

[rochesterdriver]

Update to my work on this:

I've calculated 0.1% voltage drop under the following conditions:

1/0 stranded, insulated wire, copper of course. 12 volts, 6 amps. 40 degrees C. 25 foot run.

This is for the charging circuit of course.

Seems like it ought to work peachy.

Rich.