As many of you know, I moved my batteries from the stern to the cuddy last February.
I received a bunch of advice on wire size for the run from the cuddy to the stern that ranged between #2 & #4 AWG. Since the #4 ran a dollar per foot less than the #2, and I was advised by an installer that the #4 would be fine, I chose to save the bucks.
I first used standard lug connections at the battery and the switch at the rear. During start-up the lugs on the battery got too hot to touch and the motor really lugged. Changed the battery connection to the auto style and cured much of that problem. Does not heat at all and the lug reduced.
The motor would start ok but it would still seriously lug as the starter spooled up. I got around this by starting the kicker first and letting it backfeed the system while I started the main. Not the best way to run things, but the tech's at the shop assured me there would be no problem.
While in the shop for it's annual last month, the tech's found there was a 2 volt drop through the #4 wiring. That's a 17% loss. I was trying to run a 12v starter with 10v. Not good. :hoboy:
So now I am pulling the #4's and going to order #2 from Greg's marine. :doh: For those of you who recommended I go with #2 in the first place, you each get to put a "I told you so" on your calendars. :biggrin: I should have listened to your sage advice. :bowdown:
I will soon have a couple of 16' +/- runs of #4 AWG tinned red and black available for trade. Let me know if you can use it.
StreamFixer
It would add bulk & weight to your system but you could run a second #4 AWG in parallel with the existing #4. Or at least I think you can do that. Cheaper that way.
Kimbrey
Would save a few bucks, However, I think I'll just run a #2 and be done with it. A couple of 'tight quarters' on the run and is in keeping with my underlying KISS mode (when I can). I guess I could get Woody involved and really make it Squirrely :hoboy: Or Danno and do it 'right' :facepalm: or maybe even 3wt and be all technical :doh:
KISS wins :applause:
StreamFixer
If you ever plan to install some electric downriggers, washdown, etc... hold onto that #4... can use it to run a feed to a fuse block at the back, then wire the accessories off of it.
I am just about ready to move my batteries forward. May head by Mr. Plywood today to look at MDO plywood for building a mounting base/brackets... I am nervous about screws pulling out of Star Board over time.
3WT
My screws are holding solid. No sign of glass 'dust'. However, it could be hidden amongst the piles of plywood dust being created by the platform bouncing up and down against the mounting bolt threads. Several passengers have commented when observing the platform bouncing when running against wind wave/chop. Sure glad I put the shock absorber system in.
You have seen my relatively simple double shock absorber system. Let me know if you have questions.
StreamFixer
Put me down for a wire pulling bash when you get the stuff.
Woody
Quote from: woody on January 01, 2012, 11:49:44 AM
Put me down for a wire pulling bash when you get the stuff.
Woodt
Woodt ??
Not sure what you are talking about Crocker ... I looked up and didn't see anything wrong.
Time for old man glasses?
The Woodman aka Woody, aka Woodt and many other titles bestowed by the PDX Rats
Croaker
Be kind. He is old and feeble. Besides, he has a new cat and is going through a training period. The cat is almost finished with him. :party:
StreamFixer
Standby. Wait till he sees your cat abuse post.
I think you should look at the tables for voltage drop again. I think you need bigger than 2 for that long of a roundtrip run. Hey you are losing 2 volts now and only going up one size. Hate to see you doing it again and again. I personally went with 1/0 on a 13' run. Goodluck
I have heard that the general rule of thumb on the starter draw for an outboard is 1 amp per 1 cubic inch of displacement. One place I think folks go wrong is only basing the estimate on the positive cable... the "run" is the combined length of both the positive and the negative cables.
Using the Blue Sea Circuit Wizard found here:
http://circuitwizard.bluesea.com (http://circuitwizard.bluesea.com)
I assume 100 amp draw for my 95 cubic inch Suzuki, and a 30' run (15' for both cables), with 3% allowable voltage drop, calculator says 0 GA, 5% drop = 3 GA, and 10% drop = 6 GA.
The current Yamaha 115 is 106 CI, rounded up to 110 amps, the same assumptions 3% = 0 GA, 5% = 2 GA, 10% = 4 GA.
I am sure they assume a straight run, with no loss to fuses, terminals, and such.
Using 3WT's calc's I should be getting about 10.8 v to the starter. The shop tells me it is getting 10v. I must assume the difference is being absorbed in connections and switches.
That being said, I am anticipating replacing a 14 foot run (both wires) with either 1 or 1/0. The calculator I am using suggests I will have a 0.1 volt difference delivery between the two http://www.gadgetjq.com/wiring_size_guide.htm The percentage difference is 0.8% loss.
The 1 wire runs $3.49 and the 1/0 runs $4.39 at Greg's Marine Wire. The AWG 4 that I am running now just barely works. (max amp transmission for starting is 60a for the 4, 119a for the 1 and 190a for 1/0). The max amp transmission pretty much tells the story in regards to my problem. So following the rule of thumb, I need 115 amps for my 115 motor.
For just a 0.1 volt gain, I do not see the value of going with the 1/0. Besides it has to be a bunch harder to handle. I may salvage some of my AWG 4 to replace the couple of feet of AWG 6 from the switches in the rear to the motor. That is the next check into for this project.
I am ordering 14 feet of AWG 1 tinned wire with 3/8 lug on one end and auto battery terminal on the other, red and black.
I'll let you know how it works out.
StreamFixer
I think you are making the right choice w/ the #1.
Are you running all the way back to the motor, or do you have a post set up of some kind at the rear of the boat? When I get around to doing mine, I will likely connect the motor the new cable with something like this at the back of the boat:
(http://images.jamestowndistributors.com/images/large/59153.jpg)
From Cuddy back to a total system on/off, then a battery selector perko (probably accounts for most of my voltage loss) then to the motor. Since I am advised by Yammi techs it does not matter if both motors on line at the same time, I make take the perko out of the line. The run to the motor presently AWG 6. If fairly straight forward, I may change out the 6 with left over 4. Not much difference, but cannot hurt.
StreamFixer
I cannot do that with my batteries as I plan to actually sleep in the cuddy...eventually.
Yes...@ 5'7" I can sleep in there. On the off chance (and I do mean off chance) that my lovely bride would go with me she is only 4'11" and easily can sleep in there.
I figure since I have the complete original cusions why not use it for what it is intended for.
I have other things in my long range plans for the boat to make it more favoable to cruising too...But that's another thread.
Terry B.
Took the boat out Thursday, the new battery to starter wiring made a HUGE difference.
Instead of the lugging turn over (you know, the one that grabs at the pit of your stomach and you wonder if it will make it this time, even though it always has in the past), the motor spun right up. Been sitting all winter and started in about 15 seconds.
For folks who plan to move batteries, use AWG1 not AWG4 between your battery and motor, or at least to where your present starter wiring is today.
StreamFixer
The motor ran so much better with the new wiring that it idled at 2500 RPM in appreciation :biggrin: which made shifting into gear a really memorable moment. :bigshock: So much better to do that shakedown cruise before the salmon bite starts, eh? (Thru that last in for Woody)
Paul
I can appreciate that FishorCrab. But since Woody re-assembled the controller panel after installing a new ignition switch, and that is where the problem was .....
Hmmmmm :nono: I guess he wins the big enchilada... :shrug9:
StreamFixer
Way to go SF glad you got it tightened up. We have all had that slow turnover and then it stops turning ....no fun. I like anything we can do to get more juice to where it's needed especially the starter.
This makes me want to shorten my battery cables.
Took the 17 out Sunday. With the new larger wire, the motor turned over just as if the battery was only a foot or so away.
StreamFixer
I also have a battery move update to report.
Moved one of the two batteries to the cuddy prior to the beginning of last season, used 4 awg cable and had no issues, although it should be said that the battery did not see much use. For this season I decided to move the battery back to the stb sponsoon - the issue is side to side weight distribution - the boat was balanced before I moved the battery, but with one battery up front, the boat was listing and in the end it just got annoying.
I know I could have done other things to balance out the boat, but for the time being this is a quick and inexpensive solution.
johan
Quote from: Enniberg on March 28, 2012, 11:10:30 PM
this is a quick and inexpensive solution.
johan
Somehow I thought as a moderator that you would know better than to make a post such as putting up this Blaspheme.....
Come on Johan ... We're talking boats here .... sometimes quick might be allowed, but (dare I repeat it :doh:) "Inexpensive" :hoboy:
:nono: :facepalm: The shame of it all ... This is, after all, a family oriented site. :redface:
:biggrin: :jester:
StreamFixer