12v vs. 24v windlass?

[akuakai]

I need to buy my first electric windlass. Any thoughts on 12 volt vs 24 volt? Can a 12 volt electrical system be configured to be both 12 volt for all systems but the windlass and 24 volt for the windlass? Seems like the batteries need to be configured one way or the other.

[model 10]

How much will good sized cables cost to run fwd to the windlass? The fancy relays that make 24v, sound too complicated and expensive. A 24v windlass won't work any better than a 12v if you have the proper sized electrical cables.

[noelex 77]

Originally Posted by akuakai

Seems like the batteries need to be configured one way or the other.

Yes, this is generally true.

Boats with a 12v system that want to fit a 24v windlass usually fit a dedicated 24v battery at the bow to power the windlass. There are other options with relays etc but all solutions are messy with several drawbacks.

12v windlasses are available with models that have up to a 3500lb pull. I think cruising boats are better fitting an oversized windlass, but even allowing for this, these models are OK for monohulls up to perhaps 50 -55 feet. The windlass manufacturers are less conservative and rate these models up to around 65 feet or more.

If you want an electric windlass rated over about 3500 lb it has to be 24v. Even for lower rated models, they will generally perform slightly better on 24v, but if the boat has a 12v battery system I would stay with a 12v windlass.

What size boat do you have?

[akuakai]

Thanks for the input. I'm building a 42' catamaran. The boat is more of a coastal cruiser. The hulls aren't going to allow the buoyancy of a full fledged cruiser. Thus every decision is based on weight more than anything else. Hoping to come in at 9000 lbs lightship. My mantra has been light and simple throughout the build so your advice to stay in the world of 12 volt is well received.

Windlass will be in the main cross beam so cable run is only about 15'.

[noelex 77]

Congratulations on the build.

If you are trying to save as much weight as possible, installing a house bank of 24v not just for the windlass, but most systems, will help. The weight of wire is higher than most people imagine, especially with the wide beam of a cat.

On the other hand, a 12v system is simpler. There are no perfect answers.

[JOHNMARDALL]

For any given DC electric windlass, the motor on the 24 volt version will run cooler and therefore longer than the 12 volt version. However, unless you have a genset able to power a 24 volt charger or a 24 volt alternator, to charge a dedicated 24 volt battery bank, the only option is to install a series/parallel switch, an expensive and error prone device that will temporarily rewire a pair of batteries wired in parallel at 12 volts, to a series connection at 24 volts. I wouldn't recommend a series/parallel switch and think that a properly selected 12 volt windass will need your needs. Of course, if you're going to install two engines (as opposed to a single engine with hydraulic drives), you could put a 12 volt alternator on one engine and a 24 volt alternator on the other engine, and use 24 volt DC motors on all powered devices.

I hope that helps
John Mardall
Vetus Maxwell Group

[model 10]

Originally Posted by akuakai

Windlass will be in the main cross beam so cable run is only about 15'.

You will have 3 runs of + if you use a relay. You can find cable pieces on ebay that might fit if you can move the relay around. Color does not matter, use colored tape on the ends.

[akuakai]

thanks, I hadn't thought of 24 volt battery bank on one engine and 12 volt on the other. Interesting.... We're going fairly spartan on electronics, not sure if there will be another big current draw other than the windlass.