powering my new windlass

[Brett Parker]

Just purchased my new HRC 10-10 Maxwell windlass. It has a 135amp circuit breaker and a 1200w motor. Back not going to be happy  manning in my Rocna anchor and 10mm chain for much longer!

I run 2 x 9.9 yamahas on my T38 which only put out 6 amps each. I have 4 x50 w solar panels and 2 x 6v trojan golf cart batteries. Just trying to decide whether to add another couple of 6 v batteries(which I have been given) or get a seperate cranking battery . I could increase my solar panels considerably. Its not so easy for those of us running outboards as opposed to diesels with grunty alternators. Would prefer not to get a seperate petrol generator to provide extra juice while pulling up the anchor. Ideas and direction much appreciated.

regards Brett

[Björn]

On my Tiki 38 I have two 200 AmpH batteries forward of the outboards and about 300W peak solar. On this, the fridge runs all summer long without being turned off. This allows also for navigation electronics, vhf , electrical self steering and lights as well as computer charging. The 1500 W windlass does not really run that often anyway (max a few minutes a day). During my 3 weeks summer vacation I never needed shore power or the generator running.

[Budget Boater]

Brett,

Exactly how often do you expect to be operating your windlass? Even if you operate it twice per day (that is a LOT), the power required is negligible.

1200W (max) divided by 12V = 100Ah

100Ah divided by 60 minutes = 1.67Ah per minute of run time

4 minutes of operating time per haul is above average unless you will be in very deep water.

4 minutes times 1.67Ah = 6.67Ah per haul

2 hauls per day times 6.67Ah = 13.3Ah per day (and that is if you haul twice per day, and if your windlass is using maximum wattage, which it will most likely never do.)

Your battery bank is 220Ah, so the 13.3Ah represents 6% of your total bank capacity. One hour of sunlight on your 200W solar array will replace the power consumed by two hauls per day.

I am not sure why you think you need a generator just to run your windlass. Seems overly extreme to me, not to mention the expense of the generator, fuel, and maintenance. If you are really that worried, just add two more Trojans - it's much cheaper and will double your power available for other uses.

[andy solywoda]

Ahoy Capn Brett,

1200W/12V=100A
The 100A are at full capacity, which is only reached after slack is taken up.  It is wise to stop at that point and let the strain do its work to realign the anchor, chain, etc.  Normally the boat will then be pulled along and slack will appear in the rode, then take up the slack, and so on.  Because you are only running the windlass for a minute or two at light load, its electrical draw is small.  The difference is when you are hauling during a wind event and the boat is always putting tension on the gear.  If you are weighing anchor, you would normally have the engine running, even if only on standby, so using that to put slack into the gear (not so much as to snag the prop!), the draw from the windlass is still low.  When all the slack that can be taken up is taken up, then wait for a swell or movement of the boat to break the anchor out.  Then haul it up.  Although the overall draw of the windlass isn't a lot when averaged over time, the momentary draw is large and requires large cables to reduce resistance at high current loads.  My engine battery is maybe 100 AH dual purpose, so it isn't even a deep cycle, and the windlass is a SL Sprint 1500.  The cable run is about 20 feet with #2 cable.  This is smaller, I think than your windlass, but even so, the power to pull up slack and a certain weight anchor will be the same no matter what you are using.  I've met several sailors who have tried to pull the boat to the anchor and break out the anchor with the windlass only to fry the electrics.  Hope this is helpful.

Oh, and I am running a single outboard, Yamaha T50 with no other charging to the battery.

[Brett Parker]

Thanks for the all the great feedback and info. "Electrikery" is not my  area of strength! I am currently building a new mast beam forward and was thinking of possibly storing another battery just under the capstan similar to the t46 set up. My batteries are currently in the pod at present so might just see how I go with what I've got and add to this if necessary.  Was unsure whether this sort of draw was good for a deep cycle battery or whether a crank battery was more suited. I will be living aboard next year and like to sail and fish and interact with our local dolphins and whales here in New Zealand. I want my system to work well as you do!

Anymore experience appreciated...:)

andy solywoda said:

Ahoy Capn Brett,

1200W/12V=100A
The 100A are at full capacity, which is only reached after slack is taken up.  It is wise to stop at that point and let the strain do its work to realign the anchor, chain, etc.  Normally the boat will then be pulled along and slack will appear in the rode, then take up the slack, and so on.  Because you are only running the windlass for a minute or two at light load, its electrical draw is small.  The difference is when you are hauling during a wind event and the boat is always putting tension on the gear.  If you are weighing anchor, you would normally have the engine running, even if only on standby, so using that to put slack into the gear (not so much as to snag the prop!), the draw from the windlass is still low.  When all the slack that can be taken up is taken up, then wait for a swell or movement of the boat to break the anchor out.  Then haul it up.  Although the overall draw of the windlass isn't a lot when averaged over time, the momentary draw is large and requires large cables to reduce resistance at high current loads.  My engine battery is maybe 100 AH dual purpose, so it isn't even a deep cycle, and the windlass is a SL Sprint 1500.  The cable run is about 20 feet with #2 cable.  This is smaller, I think than your windlass, but even so, the power to pull up slack and a certain weight anchor will be the same no matter what you are using.  I've met several sailors who have tried to pull the boat to the anchor and break out the anchor with the windlass only to fry the electrics.  Hope this is helpful.

Oh, and I am running a single outboard, Yamaha T50 with no other charging to the battery.

[Budget Boater]

Deep cycle batteries are rated on the power they can produce at a given rate of discharge. Your Trojan batteries for example are rated at 220Ah at a discharge rate of 20 Amps constant. If you discharge them at a lower Amp (A) rate, then the Amp hour (Ah) rating goes up and vice versa.

In the case of your 1200W windlass, a 100A draw rate will reduce the bank's Ah rating significantly if usage were continuous. However because the high discharge rate is momentary - only a few minutes in a 24 hour battery cycle period, the difference is insignificant overall (less than 1%.)

A "dual purpose" battery or starting battery should not normally be used for long term heavy draw. These battery types are designed to deliver maximum power in a short duration for starting purposes. Instead of rating by Ah, they are rated by Cold Cranking Amps (CCA.) These are fine to use for a windlass. However, they must be immediately recharged to maintain longevity, which is why they are used to start engines with installed alternators that immediately recharge them. You do not have this capacity (unless you want to wire your outboards directly to this battery and keep the engines running until the battery is fully recharged (about 35-70 minutes in your case), and creating a charging system just for a separate windlass battery is a bit overkill as well as expensive.

I cruised and lived at anchor for nearly 12 years, only visiting a dock temporarily when my children were born. The 1200W windlass was used daily from a pair of 4D deep cycle house batteries. This bank also did everything else: started the diesel, ran the 1.5hp (1100W) DC refrigeration motor for two hours per day, as well as the lights, fans, computers, TV, nav equipment, hydraulic autopilot motor, and any other electronics we had on board.

Unless you expect to be hauling the anchor many times per day, you have plenty of power available already. But as Andy said, proper cable size is critical - 6 AWG minimum for up to 7.5m round trip; 4 AWG for up to 14m round trip.

[Brett Parker]

Thanks so much for that! I'm feeling much happier about proceeding with what I've got and can tweak as I go along if I see I need to. Will make sure my cable is right too. Nothing beats the experience of others. You never know what to believe when someone is trying to sell you something right? Much appreciated!

Budget Boater said:

Deep cycle batteries are rated on the power they can produce at a given rate of discharge. Your Trojan batteries for example are rated at 220Ah at a discharge rate of 20 Amps constant. If you discharge them at a lower Amp (A) rate, then the Amp hour (Ah) rating goes up and vice versa.

In the case of your 1200W windlass, a 100A draw rate will reduce the bank's Ah rating significantly if usage were continuous. However because the high discharge rate is momentary - only a few minutes in a 24 hour battery cycle period, the difference is insignificant overall (less than 1%.)

A "dual purpose" battery or starting battery should not normally be used for long term heavy draw. These battery types are designed to deliver maximum power in a short duration for starting purposes. Instead of rating by Ah, they are rated by Cold Cranking Amps (CCA.) These are fine to use for a windlass. However, they must be immediately recharged to maintain longevity, which is why they are used to start engines with installed alternators that immediately recharge them. You do not have this capacity (unless you want to wire your outboards directly to this battery and keep the engines running until the battery is fully recharged (about 35-70 minutes in your case), and creating a charging system just for a separate windlass battery is a bit overkill as well as expensive.

I cruised and lived at anchor for nearly 12 years, only visiting a dock temporarily when my children were born. The 1200W windlass was used daily from a pair of 4D deep cycle house batteries. This bank also did everything else: started the diesel, ran the 1.5hp (1100W) DC refrigeration motor for two hours per day, as well as the lights, fans, computers, TV, nav equipment, hydraulic autopilot motor, and any other electronics we had on board.

Unless you expect to be hauling the anchor many times per day, you have plenty of power available already. But as Andy said, proper cable size is critical - 6 AWG minimum for up to 7.5m round trip; 4 AWG for up to 14m round trip.

[Ann and Neville Clement]

Hi Brett,

On Peace IV, a Tiki 46, we have a separate battery for our Ideal windlass and when it is time to raise the 88 pound anchor we used every day, we first started a little Honda 1000 generator which was connected to a smart charger so the battery was efficently charged.  Only when that generator was running, did we then ask the windlass to raise the anchor and we allowed the battery to continue charging until we were well out of the anchorage and sails were up, and the two 20 hp Yamaha outboards were raise and off.  That way the windlass battery was always well up and ready to go just in case of an emergency.  We did not have any particular emergency, as I recall, but it was nice knowing we could lower and raise the anchor and chain a couple of times if we needed to do so with no generator running.  Because we were elderly (still are!) we really relied on that windlass, so we kept a second Honda generator aboard just in case.  Our main theme was readiness and chaos prevention.  That made life afloat so much more pleasant and relaxing.

You can see pics of our installation on our web page here at Wharram Builders and Friends.  Peace is for sale now, unfortunately.  Old age got us in the end...

Ann and Nev

[Brett Parker]

Were you using a deep cycle battery or a cranking/starting battery? and what size was the windlass? I really love your ship. If I had a few more pennies lying around I could be keen but I am happy with my new(9months ) second hand T38. thanks for the reply and I enjoy the answers you give to peoples questions etc. Thanks Brett

Ann and Neville Clement said:

Hi Brett,

On Peace IV, a Tiki 46, we have a separate battery for our Ideal windlass and when it is time to raise the 88 pound anchor we used every day, we first started a little Honda 1000 generator which was connected to a smart charger so the battery was efficently charged.  Only when that generator was running, did we then ask the windlass to raise the anchor and we allowed the battery to continue charging until we were well out of the anchorage and sails were up, and the two 20 hp Yamaha outboards were raise and off.  That way the windlass battery was always well up and ready to go just in case of an emergency.  We did not have any particular emergency, as I recall, but it was nice knowing we could lower and raise the anchor and chain a couple of times if we needed to do so with no generator running.  Because we were elderly (still are!) we really relied on that windlass, so we kept a second Honda generator aboard just in case.  Our main theme was readiness and chaos prevention.  That made life afloat so much more pleasant and relaxing.

You can see pics of our installation on our web page here at Wharram Builders and Friends.  Peace is for sale now, unfortunately.  Old age got us in the end...

Ann and Nev