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post #2 of Old 02-12-2010
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Berkshire cable is excellent stuff...better than Ancor IMHO and less expensive to boot. I recommend them all the time, and use them quite a bit myself. The wire seems to be more flexible than the Ancor brand stuff. I like it a lot.

I would highly recommend getting a battery specifically for the windlass and placing it forward in the boat, near the anchor locker, so that you do not need to run 20'+ of 4/0 cable. The reason for this is simple, 4/0 cable is fairly expensive and fairly heavy, and by putting the battery forward and using a duocharge or echocharge unit to charge it, you can run much smaller diameter wire forward to handle the charging loads. Also, the shorter the run from the battery to the windlass, the higher the voltage will be and the better the windlass will work.

IMHO, the first battery you've picked is pretty lousy for this purpose. It isn't big enough. It is only 26 amp hours. Given that the battery should only be run down to the 50% depth of discharge level, that means you have effectively 13 amp-hours of operation time. The windlass (note spelling) draws 85 amps... if you have 13 amp-hours—that is less than 10 minutes of windlass use... I can see many situations, like where you have to reset the anchor multiple times, that that would not be enough power. Even the second battery is a bit light on power, given the demands that your windlass may have.

I'd also point out that the AMP-HOUR rating on most batteries is a 20-hour amp-hour rating, and if you are using significantly higher loads, the total amp-hours you will get out of a battery will be significantly less due to the Peukert factor. The higher the load is in relation to the battery bank size, the lower the effective available total amp-hours. In the case of your first battery, you'd probably be lucky to get ten minutes of use before the windlass killed the battery entirely.

Finally, I'd point out that you probably don't want to use the same battery for starting the engine as for powering the windlass. You could get royally screwed in certain situations where you killed the battery using the windlass, and couldn't start the engine because of that. Having a separate engine start battery that is not used for anything else is probably the wisest idea.

Originally Posted by SanDiegoChip View Post
Engine = 4 108 Perkins
Boat 36'

We are about to install the cabling for our Lewmar H3 windless. The run is about 22 feet. It will be no further than 25 and no less than 20. As you can see I do not have an exact measurement. I will this weekend coming.
From what I can tell a 4/0 battery cable would be the size to use. I am not positive though. Can someone say for sure so I can make the purchase as soon as I make the exact measurement leaving room for error?


Lewmar H3 windless

12 volt
Motor Power = 1000W
Max Pull (Kg) = 890
Working Load (Kg) =215
Normal Current Draw = 85A
Circuit Breaker = 110A

Also I was thinking of going with Berkshire marine cable, made here in the USA. Any good or bad on this brand?
Berkshire Electric Cable Co., Leeds, Massachusetts USA

And what battery would be recommended? This battery will be used as a starting battery and a windless battery.

Any bad or good on this maintance free West Marine AGM PWC* Battery, 26 Ah, 500 MCA? It is both deep cycle and starting applications. Price seems ok.

Thank you,


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Telstar 28
New England

You know what the first rule of sailing is? ...Love. You can learn all the math in the 'verse, but you take
a boat to the sea you don't love, she'll shake you off just as sure as the turning of the worlds. Love keeps
her going when she oughta fall down, tells you she's hurting 'fore she keens. Makes her a home.

—Cpt. Mal Reynolds, Serenity (edited)

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Last edited by sailingdog; 02-12-2010 at 12:02 PM.
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