Normal prudence dictates that one runs the
engine when raising anchor....if nothing else by doing so one has more options available should something go wrong with the
wind and tide. Cruisers WOULD necessarily have adjustable or settable (by one means or another) multi-step regulators driving a high output
alternator. Therefore, in anticipation of raising the anchor the engine could be run sufficiently long so as to have the
service batteries at or near an acceptance voltage of around 14.4V.
Even with a 0.4V drop across the
cables you would deliver close to 140A (with a 165A alternator running not at high speed) to the windlass motor. This situation marks a HUGE benefit over planning to use oversized wire and oversized
fuses or breakers.
BTW: I agree with pblais' comments. Nuisance blowing of a windlass fuse is not acceptable. Use a properly rated breaker (including the time-current curve).
Now realize that you will not normally even come close to drawing that 2000W when raising anchor and, therefore, the windlass will run quite briskly with nice quick retreival rates not achievable without running the engine and using depleted house batteries.
Forget placing an auxillary battery near the bow....you merely add to the pitching moment of the
boat which, for cruisers, is usually too much due to all that chain, and anchors, etc. carried forward.
No offense, SG, but that Yandia link advises using an unacceptable 50A combiner which would have to be protected with
fuses or breakers. Even so, a fuse or breaker which would not nuisance blow would NOT protect against the combiner point contact abuse due to surge currents imparted with 2000W loads or a high output alternator charge to the battery which would be capable of charge accepting more than 200A if it is rated to drive a 1200W or higher windlass.
Sean: it is wonderful to have a
manual windlass capability yet if one needs to retrieve much chain whilst the bow is pitching into a significant swell one needs to do it as quickly as possible. That means you have to do it by hand having strong arms, back and bracing of the body because no manual windlass will do that as fast (assuming that you are strong enough). An
electric or hydraulic windlass CAN sustain much quicker longer lasting retreivals to get you up and out of there without breaking a sweat, especially running near 14V instead of a battery resistance-sagging 12.X Volts (work out the percentage differences). Remember that windlass motors retreival rates vary DIRECTLY and linearly with applied voltage for a given load.