Powering a windlass

[VicS]

I was just going by what the downloads say from Lewmar's website....The windlass motor is 700W the current draw is 80A

Doing some arithmetic without "looking over Mitiempo's shoulder" I make that a 5% drop for 15 m of cable run using 25mm² cable ( not an AWG size )
Lewmar say up to 10% is acceptable so that should be OK

If one wanted to limit the volts drop to the usual 3% then for a 15m run the cable would have to be 43 mm². AWG 1 is 42.4mm²

BTW you do realise that the cable run lengths quoted are from battery to windlass and back again. So 15m is only a 7.5m separation between windlass and battery.

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[neale]

No, as I said, 12m total. ( The engine and batteries are just aft of the mast, so I'm cheating a bit ! ).
If this gives me 5% drop, and power is V^2, then I accept that my maximum 800w becomes 720w, but it's still far quicker and stronger than my aged muscles.
With the engine started, the volts go up even more, and since the boat usually pulls the anchor out anyway, the windlass seems to have a pretty easy time as a rule.

Ok that makes all the difference. Your 4AWG will now only have around a 5-6% voltage drop which is perfectly acceptable, hence you haven't had any problems. The next size up though would still be preferable

 

[snooks]

BTW you do realise that the cable run lengths quoted are from battery to windlass and back again. So 15m is only a 7.5m separation between windlass and battery.

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Yup realised that, Pixie is 9.6m Loa, battery compartment is 3m from the transom, windlass is 1m from the bow, so that gives me a few metres to wiggle around the boat and still be less than 15m for 25mm2 or well within the run length for the 35mm2 cable