moving batteries forward

[Sunbeam]

Okay, I get it now. Thank you! I couldn't see in my mind how the whole run (say, windlass to breaker/buss bar/switch, and then breaker/buss bar/switch to batteries) wouldn't have to add together into one long run, but on the other hand, I thought it probably didn't. Now I know it doesn't.

I hear what you are saying on the small connectors sometimes ending up way oversized. I was using #6 cable for the connections in the lazarette, and some of them are very short, but I used the #6 anyway, just because it worked out fine that way.

Lewmar's instructions (to my mind anyway) made it very unclear as to whether they were talking about a round trip distance or a one-way distance on their "here is our recommended wire size" table. They said something like "The full run from the windlass to the battery must be considered." Now I know that both ways have to be considered, but when there is a chart, very often it has been "converted" to a one-way length for simplicity to the lay person. And they were not clear which way it was (IMO). So what I did was take it to a regular voltage drop calculator online and plug in Lewmar's figures; from that I was able to tell that they meant round trip. They listed #6 for up to 50'. I considered #4 for lower voltage drop because I thought I was going to be really close to the maximum, but as the run came out to "only" around 42', I think I'll be okay sticking with the #6 (which I already have two 50' spools of, not that that would make me use it if it were too light).

Now I guess I had better figure out if I am going to move battery(s) forward, because if I do then clearly I should just run the windlass wire straight to them (in which case #6 would be very very generous in size).

OR, am I going to connect the windlass to the start battery, which will be staying in the lazarette (addressed this in another thread).

Like they say... on boats... it's all connected! That can be a pain at times.

 

[thataway]

You don't want to run the minimum, especially to a console, especially because there are always more electric items which are run off that bus bar with time (fans, more lights, another chart plotter etc).

#6 AWG (don't use SAE or other sepec wire) should be adequate from the back of the boat to the windlass on a 22. On a 22, that is gong to be over 40 feet, because of the run to the contactor, (mine is almost in a direct line, but there is still at leas a foot more to make a safe connection. You do all up all of the length of the wires. Lets say it is 15 feet to the contactor and another 8 feet to the windlass. This is 23 feet one way--you size the wire for 46 feet total run. Undersizing is a great way to damage the motor of the windlass, and overheat the wires.

You treat the total run from battery to appliance--not in segments. You measure the total length of the wire positive, plus the length of the total wire negative. You do not measure in a straight one, you measure the exact distance the wire runs.
Yes I size the short connectors the same as the longest wire run and the heaviest gauge. These connectors are part of the total run distance. Never undersize them!

 

[Sunbeam]

You don't want to run the minimum, especially to a console, especially because there are always more electric items which are run off that bus bar with time (fans, more lights, another chart plotter etc).

Just to clarify: The #6 wire I am speaking of is not feeding anything but the windlass (and won't do). I have a separate helm feed wire which I calculated generously, based on potential future items there.

#6 AWG (don't use SAE or other sepec wire)

I use Ancor marine cabling, which is tinned and stranded - presuming that is fine.

#6 should be adequate from the back of the boat to the windlass on a 22. On a 22, that is gong to be over 40 feet, because of the run to the contactor, (mine is almost in a direct line, but there is still at leas a foot more to make a safe connection.

It comes out to around 43' on my boat. I measured from the windlass (using a rope so I could make all the little twists and turns that add up), over to the gunwale, then back to the helm and in for the contactor, then back out to the gunwale, back to the lazarette, and actually to where it will connect. Then I doubled that figure to get 43'. Lewmar says #6 for up to 50', but I also looked it up on a voltage drop calculator. Looks like I am under their 10% recommendation. Of course, being me, I thought maybe I should move up to #4, but it seems from what I am reading that the #6 has worked fine for many folks with 22's, so I was going to resist the urge.

You treat the total run from battery to appliance--not in segments.

Okay, so this seems like the critical bit, and if I am reading it correctly, is the opposite of what Greg/Aurelia said. This likely won't come into play, since if I do move the house bank I will connect via the "shortcut" over to port side, but I still want to understand it. I read you as saying that if it were 43' round trip to the lazarette/switch/breaker/buss bar, and then another 24' to the batteries (which would already have, say, #2) then the run for the windlass wiring would have to be calculated as 67', thus necessitating much larger wire? I really want to be sure on this point, even if I don't "need" it due to how I end up running the wires.

Right now I think I am reading two different concepts, but I may just be misunderstanding.

Sunbeam

PS: Nothing is done yet. I am asking during the planning stage :thup

 

[thataway]

It may have been implies, but not directly stated. Size the wire for maximum current run. Assume that at one time all appliances are gong to be used. For the console, this would include, radios, chart plotters, all lights inside and out, fans, inverters, small chargers for smart phones etc.

Also when sizing the short connectors--they need to be the sized to carry the current of all wires on that circuit. For example if you have one 35 amp circuit and two 20 amp circuits--size the wire for 75 amps, not 35 amps. This is why in a properly wired boats the connectors near the battery will seem over size--they are not.

Also to expand on the working load of the 700 Windlass--if you go to the specs and manual- typical working load is 175 lbs (not 700 lbs), and the normal current draw is 35 amps, but the breaker may be from 50 to 60 amps…..

 

[Sunbeam]

I think this is getting confused.

1) I will have a wire for the windlass that is only for the windlass.

2) My helm feed wire is completely separate, and is sized to handle all loads I could imagine adding in future. I calculated this based on looking up the draw of everything I could think of. If at some point in future I add even more things than I could imagine now, it will be replaced with a yet larger wire.

Lewmar calls out 35 amps and says #6 wire is adequate for up to a 50' round trip run. As I have things set up now, the run will be 43' and I have planned to use #6 wire. If I either keep the house battery where it is, or hook the windlass up to the start battery (which will not be moving regardless), I think I should be fine.

If I decided to hook the windlass up to the house battery and move the house battery, and run the wire the "long way around," then I may need to reconsider the run length. Whether or not the run lengths were additive (as applied to the first half of the run) was the crux of my question (because whether I do it or not, it is a useful concept to know). I think I have the opposite answer from you and Greg, but I may be misunderstanding.

I hope this makes it clearer, and sorry if I muddied things up somehow.

 

[Captains Cat]

I think this horse is dead!

Charlie

 

[Sunbeam]

I was still trying to work a few things out, but I can figure it out some other way if the thread is bothersome or should be "dead."

 

[Captains Cat]

No, keep going..... :roll:

Charlie

 

[Aurelia]

Not dead yet and Sunbeam is onto something important.

I think I was unclear and we all know this stuff is not the easiest to explain. I actually appreciate the exercise and figure it will only sharpen my own understanding however imperfect that is.

1. Each segment of wire between connections should be considered.

2. The additive load at the end of the river is also critical.

Should a person connect (10) lengths, 10ft long each of 12g wire together to connect a battery and 40amp load 100ft from each other just because a 10ft length of 12g wire would work by itself? NO

Should a person consider the cumulative load as they move up or downstream in their wiring to make sure they have the capacity for all demands? YES

I look at each section and ask myself, what is the total maximum amp load and duration of draw from this section and try to size that appropriately and usually conservatively.

Marine wiring will often look a little bit like a river in reverse.

The battery end will be the fattest wire with the wire size generally going down as the loads are separated. Some channels of the river will remain fatter than others at the same distance and that just relates to the demand.

Your questions are good and I think it's time to make your battery move and go from there :wink:

 

[Hunkydory]

So Greg, after reading the comments on sizing wire for length of run, I re checked the wire size I used for installing the Lewmar H700 windless on our 22 footer. The windless factory wire leads appear to be #10, though they don't have a identifying size. When researching for the windless installation, I didn't come across anyone who had replaced these leads or if so missed it, so on installation, I connected them to #8 for the run to the contactor & from there through the breaker to the battery in #6. From your last post it seems this might be OK but does conflict with Bob's advice on same size wire from battery to appliance. Now really wondering if I need to up size the wire from the windless to the contactor or not.

Jay

 

[Aurelia]

Jay,

I can only assume the distances knowing you have a 22 and the batteries are likely in the rear of the boat. The size progression sounds like it is fine currently, but it would be much more suspect if reversed and you had a 10g section of wire near the battery end. The 10g wire leads on the windlass should be short a able to handle the loads required for operation at that end of the stream.

You would not want to extend those with more 10g wire further than 15-20ft before the peak loads of the windlass could warm things up and your voltage loss becomes problematic in some cases.

If you had a battery dedicated to the windless and it was kept under the berth area, you could use 10g safely based on the charts but that doesn't mean I would. Just for the sake of voltage loss (safety aside for the moment), sizing the wire up for a windlass used often or for longer periods would be better for the motor and yield better performance that could be quite noticeable.

I can hear the pitch difference in my air compressor plugged into different outlets in my garage for similar reasons. And that does relate to performance.

Greg

 

[thataway]

Charlie there are people who are confused, and that confusion needs to be clarified. The lengths of wire are additive in a single circuit.

You would not want to extend those with more 10g wire further than 15-20ft before the peak loads of the windlass could warm things up and your voltage loss becomes problematic in some cases.

Greg, please go to the tables for this windlass: There is no case where #10 wire is correct. You never want to put a smaller wire in the series. It then begins to act like a fuse.

The "river" concept may be used, but you have to have the correct wire size all of the distance from battery to the appliance rated by amps draw of the final appliance. In the windlass circuit--which is being discussed there, there should be one standard wire size all of the way to the appliance. If the table calls for #6, then #6 all of the way.

For example you may have 2/0 wire from the battery to your first circuit breaker--and #6 wire from the circuit breaker to the windlass circuit breaker-then #6 wire to the contactor finally #6 wire to the leads from the windlass.

Lewmar is made in England, and for some very strange reason (metric stuff), wire is measured in sq mm. over there. The wire on the windless is 10 sq. mm surface area (or #7 AWG wire (but we don't often use #7 wire). I cut these leads as short as possible. I have #6 (red) from the junction of the wires on the windlass to the battery. and #6 black on the negative side.

The table on page 13 of the manual on line states:
in AWG (American Wire Gauge--we are still fighting the revolutionary war) you must have: 0-23 feet #8 AWG, 23 to 50 feet #6 AWG, and 50 to 73 feet #4 AWG wire. Most of our boats are gong to be more than 23 feet, less than 50 feet total run. The odd numbers are used, because the brits are thinking of metric--0-7 meters is 0-23 feet (approximately).

 

[Hunkydory]

Greg, thanks for the feedback & yes the batteries are in the stern, the windless lead wires only about 4 ft, & #8 wire from lead to contactor at most 5 ft & the rest to the battery all #6.

Bob, because of the much smaller physical size of the lead wires, I guessed them at approximately #10, so glad to hear they are actually #7. In my research before wiring I found several that had wired theirs with the reduced lead wired connected to #8 to the contactor with #6 from there to the battery in the stern, so that combined to the smaller appearing lead wire convinced me to do the same. Now, not so happy to hear a redo might be in order, but perhaps best to do it.

Jay

 

[Sunbeam]

Everyone:
Thank you for not giving up on me here - I want to understand the concepts, but it's not always easy (although it is probably totally obvious to those who do already get it). I'm tempted to just stop posting, but darnit, I almost have it!.

For example you may have 2/0 wire from the battery to your first circuit breaker--and #6 wire from the circuit breaker to the windlass circuit breaker-then #6 wire to the contactor finally #6 wire to the leads from the windlass.

An element of my confusion is still present here. If you could just humor me one more time, I think I will have it. So just ignoring everything else we know about my particular setup, and taking the following example in isolation:

1) Windlass on bow, with a 43' round trip run from the windlass, to the Lewmar breaker and the positive and negative bus. With this in isolation, I know #6 wire is fine.

2) 24' round trip run from positive and negative bus to battery. For other reasons, this has #2 wire which is perfectly adequate.

Now, my question.

A) Is the #6 in point 1 still correct? Or does it need to be changed to #4, because as per Lewmar's chart, a 50-73' run needs #4, and now the 24' of #2 wire leading to the battery needs to be included in the length for the calculation of the wire in point 1? Meaning that then there would be 24' of #2 and 43' of #4.

Or,
B) is the #6 fine for where it is, and the #2 fine for where it is, and that's okay (I think you say that in the quote above, but then there is the "additive" part?

If I just get the answer to this, then I think I'm good. I will stop posting in the thread and go drill holes in balsa core

 

[Aurelia]

When it doubt, follow the instructions.

With a breaker size of 50A which I will assume is not below the max amp draw of the windlass, and depending on the chart you reference, a length of 10g wire could handle up to 50 amps for a length of up to 20ft (10% loss) so it would move the current and "run" the windlass.

But, if the chart you reference is based on a lower voltage loss, it may say 8g, or even 6g is the smallest you should use for that scenario.

The unknown is the voltage tolerance of a given electrical device and in this case I can assume Lewmar does not want more than roughly 3% voltage loss. They just don't expressly say that. They are acting conservatively on the wire recommendation to get the best performance and life from there product and that is what most owners would choose to follow.

Running a smaller gauge wire would run the windlass but it may not perform to their advertised specs and that puts them in a bind. Or it might not last the beyond the three years of warranty coverage and now they have to cough up an new one. Or not.....

warranty exclusion: "deficient installation of the product"

So if you don't use 8g as the minimum recommended for any installation, they may not honor the warranty, but I would be surprised to see them verify the installation on a given boat given a warranty claim. Not saying anyone should cheat the company of course as I would not personally. I just like to understand the reasoning behind the details as does Bob I would bet.

One of those devil in the details situations.

Additional related question for anyone and I will post it in the electrical forum as well.

If I had a 30ft run made up of three lengths of wire each 10ft long, butt connected in 6 then 8, then 10 gauge, is the maximum amp rating based on the smallest wire or an average of the three? Do I get "credit" for the lower resistance of the larger lengths that applies to the smaller length?

I don't know the answer and I am not sure it is simple.

Greg

 

[thataway]

Sunbeam: Suggestion: wire the boat as you have it set up now. Go use the boat. for a year. Decide if you want to move the batteries after using it--and determine if you want to upgrade batteries to Li ion, or larger AGM. You are well into the boating season now.

If you move the batteries, to the port forward, then take the leads directly from the batteries on the port side to the windlass, with #6 wire.

If you are going from a larger gauge wire to a smaller gauge wire, this is correct. You can continue with the #6 wire after the #2 (larger wire) But that makes little sense. Use the shortest run possible.

The other issue, is the number 2 wire--is OK--for starting loads. But starting only, if you start putting other drains on it, thru the same wires, you have gone up in amperage use.

Jay, what I would do is to measure voltage at the contactor (because this is an easy place to check voltage, without cracking open the insulation.). You can do this with alligator clips from the output side of the contractor to the volt meter leads when the windlass is under load. If you have more than 10% voltage drop, then larger wires are going to be in order. Of course all of this is sized for working loads--if you go the the extreme of stalling the motor, then you can blow the breaker, or heat up the motor (and this is why a fairly small 35 amp breaker is used on the windlass circuit). I have had large windlasses which had 200 amp fuses at 24 volts(equal to 400 amps at 12 volts). In that case I had the batteries about 8 feet from the windlass and used 2/0 cable.

 

[Hunkydory]

Thanks Bob, I will do as you suggest the next time I have the boat on the water.

Jay

 

[Sunbeam]

Sunbeam: Suggestion: wire the boat as you have it set up now. Go use the boat. for a year. Decide if you want to move the batteries after using it--and determine if you want to upgrade batteries to Li ion, or larger AGM. You are well into the boating season now.

I could do that, and it is an option I considered. However, after only 5 weeks on Powell with things set up as they are now, I could tell I wanted to make some changes.

1) I was/am really tired of the major list to starboard, and there is really nothing heavy left that I can move to port, except the batteries. Connected to this is that I got a good idea of how much amperage I like to use on a daily basis (not need, but like - but then the boat is all about "like"), and I decided I would like a few more available amp hours. However, I am currently limited to one battery, because it is already about 5 times the size of the alternator output for the engine (plus the lazarette is full). So, to keep things balanced, I need to add charging capability. For my uses, a solar panel is desirable. So, that's a solar panel, and then I can add a second house battery and still be basically in power balance. Now I have a chance to correct my permanent list (which I don't want to experience for a year!).

2) I'm putting in a windlass because after five weeks of hoisting the anchor by hand, I can tell I don't want to keep doing it if I don't need to. I don't think my shoulders will last another year of that, or at least I don't want to find out. :shock:

3) The anchor snubbing setup on the boat was not working very well, and will be worse with the added windlass. I am hoping to improve that as I add the windlass (cleats/fairleads). Tying the two rodes together with small stuff at the end of the roller sort of worked, but not ideal, especially in certain anchorages.

4) It's all connected! (Boats, sheesh)

I realize it is summer, and we are in what people consider "the season." I can tell other people would enjoy it more if I were out boating. But I am choosing to do some upgrades to the boat now for several reasons:

a) I have an excellent place to do them
b) I want to have them done before Powell, which is sort of my "feature trip."
c) I don't want to have the same exact issues I did last year there repeated (not that they were so bad, but I'd like to go back with my new mods to try out).
d) I just want to.

I realize I will probably know more after another year, but I am "saving" plenty of things until I have more experience. Heck, I still have a temporary water tank setup of 6-gallon jugs until I decide what to change about it. And a circa 2002 chart plotter, cable steering, no autpilot, etc. So there is a lot left to learn about and make decisions on :thup I know that often if I decide to make changes right away, I'll change my mind after more use. This is why I held off until after Powell to do the windlass.

If you move the batteries, to the port forward, then take the leads directly from the batteries on the port side to the windlass, with #6 wire.

I am thinking that I would like to run the windlass to the start battery, and I thought as a result of the previous discussion this was okay. Is it not?

If you are going from a larger gauge wire to a smaller gauge wire, this is correct. You can continue with the #6 wire after the #2 (larger wire) But that makes little sense. Use the shortest run possible.

I realize running the windlass wires straight to the house bank in the port locker would be the best route if running it to the house bank, and that is what I would do; the reason I kept asking about the longer run is that I wanted to understand the concept (as applied to any of a number of other situations). Now Greg has asked about it in another thread, so I can finish learning about that part there.

The other issue, is the number 2 wire--is OK--for starting loads. But starting only, if you start putting other drains on it, thru the same wires, you have gone up in amperage use.

Okay, so it sounds like #2 wire would be inadequate for a house bank with a 24' round trip run to the rest of the components (switch, etc.). I will figure out what would be adequate if/when I move the bank. I have zero need or desire to "scrimp" (of course no need for major overkill either, since cable is heavy and unwieldy as it gets larger).

Thanks for the help and taking the time to write it all out.
Sunbeam

 

[Sunbeam]

With a breaker size of 50A which I will assume is not below the max amp draw of the windlass

Jay and I have the same windlass. Lewmar lists 35 amps as the draw.

The unknown is the voltage tolerance of a given electrical device and in this case I can assume Lewmar does not want more than roughly 3% voltage loss. They just don't expressly say that.

Unless I mis-read, they said to limit it to 10% voltage drop. I ran their "max round trip for X size" through a voltage drop calculator, and it was close to 10%.

 

[rogerbum]

Sunbeam: Suggestion: wire the boat as you have it set up now. Go use the boat. for a year. Decide if you want to move the batteries after using it--and determine if you want to upgrade batteries to Li ion, or larger AGM. You are well into the boating season now.

I could do that, and it is an option I considered. However, after only 5 weeks on Powell with things set up as they are now, I could tell I wanted to make some changes.

1) I was/am really tired of the major list to starboard, and there is really nothing heavy left that I can move to port, except the batteries. Connected to this is that I got a good idea of how much amperage I like to use on a daily basis (not need, but like - but then the boat is all about "like"), and I decided I would like a few more available amp hours. However, I am currently limited to one battery, because it is already about 5 times the size of the alternator output for the engine (plus the lazarette is full). So, to keep things balanced, I need to add charging capability. For my uses, a solar panel is desirable. So, that's a solar panel, and then I can add a second house battery and still be basically in power balance. Now I have a chance to correct my permanent list (which I don't want to experience for a year!).

2) I'm putting in a windlass because after five weeks of hoisting the anchor by hand, I can tell I don't want to keep doing it if I don't need to. I don't think my shoulders will last another year of that, or at least I don't want to find out. :shock:

3) The anchor snubbing setup on the boat was not working very well, and will be worse with the added windlass. I am hoping to improve that as I add the windlass (cleats/fairleads). Tying the two rodes together with small stuff at the end of the roller sort of worked, but not ideal, especially in certain anchorages.

4) It's all connected! (Boats, sheesh)

I realize it is summer, and we are in what people consider "the season." I can tell other people would enjoy it more if I were out boating. But I am choosing to do some upgrades to the boat now for several reasons:

a) I have an excellent place to do them
b) I want to have them done before Powell, which is sort of my "feature trip."
c) I don't want to have the same exact issues I did last year there repeated (not that they were so bad, but I'd like to go back with my new mods to try out).
d) I just want to.

I realize I will probably know more after another year, but I am "saving" plenty of things until I have more experience. Heck, I still have a temporary water tank setup of 6-gallon jugs until I decide what to change about it. And a circa 2002 chart plotter, cable steering, no autpilot, etc. So there is a lot left to learn about and make decisions on :thup I know that often if I decide to make changes right away, I'll change my mind after more use. This is why I held off until after Powell to do the windlass.

If you move the batteries, to the port forward, then take the leads directly from the batteries on the port side to the windlass, with #6 wire.

I am thinking that I would like to run the windlass to the start battery, and I thought as a result of the previous discussion this was okay. Is it not?

If you are going from a larger gauge wire to a smaller gauge wire, this is correct. You can continue with the #6 wire after the #2 (larger wire) But that makes little sense. Use the shortest run possible.

I realize running the windlass wires straight to the house bank in the port locker would be the best route if running it to the house bank, and that is what I would do; the reason I kept asking about the longer run is that I wanted to understand the concept (as applied to any of a number of other situations). Now Greg has asked about it in another thread, so I can finish learning about that part there.

The other issue, is the number 2 wire--is OK--for starting loads. But starting only, if you start putting other drains on it, thru the same wires, you have gone up in amperage use.

Okay, so it sounds like #2 wire would be inadequate for a house bank with a 24' round trip run to the rest of the components (switch, etc.). I will figure out what would be adequate if/when I move the bank. I have zero need or desire to "scrimp" (of course no need for major overkill either, since cable is heavy and unwieldy as it gets larger).

Thanks for the help and taking the time to write it all out.
Sunbeam

Sunbeam - many of us (me included) are either secretly or openly projecting our desires onto you. You of course can, should and will do what you want. If it were my boat, the balance between "fixing things" and using it would be way farther towards the using it side of the spectrum. But it's not my boat, it yours! :lol:

That said, both (1) and (2) above could be solved by finding a strong boating partner to pull the anchor and site in the port seat! Also, I think that Bob has a point. The more you use the boat, the more you understand/re-prioritize fixes and mods. Ideas that I had 1-2 years ago about how to improve safety on the boat no longer seem that relevant to me now that I've put a few more years and a few more 100 hours on the water in the boat. Ditto for other changes I was certain I wanted to make a few years ago.