Arima Forum => Tips & Tricks => Topic started by: StreamFixer on February 07, 2011, 01:26:19 PM

Title: Motor Wiring
Post by: StreamFixer on February 07, 2011, 01:26:19 PM
I recently upgraded my kicker to a Yamaha T8 with electric tilt and start (killer deal that I just could not pass on)  (This means I now have a great spare 8 hp 4s Johnson, but that is a different story)

I have been wrestling with how to deal with weight in the stern since the new kicker is adding yet another 30# to the stern of a 17SC that all ready has a 115 4s Yamaha and two batteries (main and a spare).

I have, after Woody's encouragement, decided to move my main and spare batteries to the cuddy on the right (helm) side.  In part, this is to help compensate for the substantial port list when on the step.  This will result in a net shift of about 80 lbs ((40 out of the stern, 40 added to the bow).  I am concerned about chop shock on standard marine batteries.  In order to minimize impact shock from chop and waves when in transit, I plan to mount the batteries on a platform and use 4 of these
  model DS 60 (lightest they make) to cushion the platform from the deck.

Then I will run a new #6 pos and negative (common ground) to the stern main power switch.  This will be a single pole/double throw marine switch.  One leg to main, the other to the kicker.  The other option would be to run 2 positives with a common ground with each motor on a separate switch.

Thoughts or comments would be appreciated. 

Title: Re: Motor Wiring
Post by: woody on February 07, 2011, 02:36:38 PM
Actually if you must know, that's a total of 3 kickers Russ has.  It was a bang up deal he got and I was with him and will vouch for the deal.

I want him to shift the batteries because I'm tired of sitting on the bow and moving right to left every time he yells.

The shock absorbers were a good find, I know we talked in the abstract, but am anxious to see.

Title: Re: Motor Wiring
Post by: StreamFixer on February 07, 2011, 05:06:39 PM
Woody is such a whiner.  :berry: I suspect he would complain if he were hung with a new rope......   :doh:

Title: Re: Motor Wiring
Post by: Threeweight on February 07, 2011, 06:16:22 PM
I still say #6 is way too small to carry the draw of the starter from the big outboard.

I would wire the kicker directly to the house battery, and skip the switch (#6 would be fine for that, w/ an inline fuse near the battery).  I would be nervous about wiring the kicker onto a switch w/ the main.

Then I'd run heavy gauge wire (at least #1 or #2) from the main motor to a Blue Sea switch (or similar) and automatic charging relay.  From there, I'd wire the switch and relay into both the house and the starting battery.

To me that would be the best set up.  The main motor would charge your starting battery all the time, and the ACR would cut in when it is at full charge and split the charge so the house gets juice.  The kicker would be available to to charge the house battery while you troll.  I don't think the draw from the kicker starting will be big enough to cause much of a voltage drop for your electronics and such.

I would look into getting a set of AGM batteries or Optimas and get rid of the lead acids.  More $$, but those batteries are sealed, so they should be less affected by the pounding (plus, in theory, they last a lot longer).  
Title: Re: Motor Wiring
Post by: StreamFixer on February 07, 2011, 06:42:12 PM

I apparently did not make my self clear.

I plan to run 1 (one) battery for both motors with a common ground.  The switch will put power to main OR kicker but not both.  The second battery is a spare "just in case"  and yes AWG #4 to switch and main, AWG #6 from switch to kicker.
Title: Re: Motor Wiring
Post by: Threeweight on February 07, 2011, 07:12:59 PM

I plan to run 1 (one) battery for both motors with a common ground.  The switch will put power to main OR kicker but not both.  The second battery is a spare "just in case"  and yes AWG #4 to switch and main, AWG #6 from switch to kicker.

Got that.  The problem I see is you have both your motors charging the starting battery, and nothing charging the house battery.  You also don't have an easy way to swap the main motor over to the house battery for emergency starting purposes (other than crawling up into the cuddy and re-wiring it), or of combining the batteries if both are drained.  

Also consider that the alternator on your kicker does not put out enough juice to re-charge a drained battery when running it at trolling speeds (but it does put out enough to maintain a battery against the draw of your electronics.)  That's why most folks wire their kickers to their house battery.

Blue Sea's wiring diagram might be helpful.


I'd suggest a similar wiring set up, but the kicker wired directly to the house battery (with an inline fuse).

Title: Re: Motor Wiring
Post by: StreamFixer on February 07, 2011, 07:29:13 PM
Let me try again

I only plan to have one battery on line for every thing.  The spare is just that.  The connection is via thumb screws. Less than a 1 minute switch. No Motor and house battery.  Just the battery and spare (not hooked up) KISS

Kicker will not use more than it generates even @ troll speed.

Title: Re: Motor Wiring
Post by: Danno on February 07, 2011, 08:19:37 PM
SF, I have zero facts to run on but everything I've read is says to stay away from lead acid batteries in the front of the boat. As 3wt noted AGm or Optimas are the way to go.

I thought that we sized the 6 gage for the kicker starter draw?  The main is going to have a lot more draw than the kicker (you already know that but after spending time with Woody, you seem to have lost a few brain cells).

I know you like wing nuts but for $30, I'd add another double pole, double throw switch at the batterries so that you can add a starting system fuse and switch or combine batteries. 20 feet of 6 AWG and a short, shorts out a lot of wire, throttle and steering.

Title: Re: Motor Wiring
Post by: Jay in Kitsap on February 07, 2011, 09:39:59 PM
I too think your wire size may be small.  I recall you have a 115 HP, if you don't know the actual starting draw a rough estimate is 1A/HP (actually it is 1A/CI displacement) so 115 Amps.  I like oomph starting and don't want to loose even 5% of voltage.  Using the Blue Sea calculator I show at least #4 to get the 15 feet forward + the 6' of engine lead.  I went with #2 with mine.  I used old house #14 wire pulled on my battery route to template the cable length, cut and measured then had Greg's marine wire make the wires with terminations.  The terminations were surprisingly cheap and no hassle.

I love my BEP battery switch, it is KISS itself.  It does the charging without any extra wires and it is waterproof except the terminals.  So my 2nd battery stays charged.  Danno yesterday posted a pic of this switch, just ahead of the starboard. 

Lead acid batteries release hydrogen, also acid spills.  Not what I want in a confined space that I might be sleeping in.  I went with the Cabalas AGM for my battery.

I’ve seen the results of a short on a battery lead, I didn’t want that.  I used the Blue Sea 150A terminal fuses on each of my batteries, some $ but I sleep at night.  Starts great, but if overloaded I don’t have a huge toaster element.

Title: Re: Motor Wiring
Post by: beancounter on February 08, 2011, 04:34:08 AM
Echo the other comments your wire size is too small I would go 1 or 1/0 and agm batteries.
Title: Re: Motor Wiring
Post by: StreamFixer on February 09, 2011, 08:26:35 PM
Had the chance to discuss my wiring scheme with a fellow who has been wiring boats for years for a living. 

He agrees the platform with the vibration mounts will be helpful.

He says pull red & black #4 from new battery location to the existing shut off switch.  Run negative to a bus bar.

Install a Perko, or equal, 2 battery switch.  Run a hot lead from the unused terminal on shut off switch to the Perko common connection.

Connect the existing motor wiring with ground to bus bar and positive to one of the battery connections on the Perko.

Run a #6 from the other Perko battery connection (positive) to the kicker as well as run #6 negative from kicker to bus bar.

All done guys.  1 battery runs the two motors with a spare for emergency use.  The battery weight transferred from stern to cuddy and onto other side of the boat to help balance the extra kicker weight.

I appreciate the comments and thought offered by the members.  However, I do have one question.  If I ran #1 or even #2 wiring, was that intended to be run clear to the motor(s)?  If so, how would you expect to make it bend/flex when you tried to steer?

Title: Re: Motor Wiring
Post by: Enniberg on February 09, 2011, 08:54:56 PM
I am in a similar situation with my boat - it came with only one battery and I am going to place the second one in the cuddy.

I already have a unused Kirkland deep cycle/starter battery sitting in my storage for a year, and because I am doing this on a budget, I am passing on the gel battery and putting this one up there. Hopefully it works for at least a couple of seasons.

I talked to the local Interstate battery dealer today and he said that in my application of a couple of hundred hours per year usage, the lead acid should do just fine.


Title: Re: Motor Wiring
Post by: StreamFixer on February 10, 2011, 07:55:49 AM

I am making a plywood platform to hold the batteries (12 mm should do but will probably use 18mm).  They will each be in a plastic battery holders like this one  The holders will be attached to the plywood to minimize slipping and sliding.  The holders will contain any leakage or spillage.

I am then mounting the platform on these guys
 .  The fellow at their office would recommend lighter, but nobody makes one.  This will absorb chop shock and, as you note, couple of hundred hours a year, probably mostly trolling  :shrug9: 

You could do it with three, but I am using 4 because I don't want to mess with getting the triangular arrangement 'just right'.  They are a bit spendy (about $30 each incl shipping) but the Canadian $ is looking really good against US at this time.

Let's continue to compare notes as our projects progress

Title: Re: Motor Wiring
Post by: Threeweight on February 10, 2011, 09:48:42 AM
A cheap, low-budget alternative to those shock absorbers you might consider...

Coastal Farm and Ranch sells thick mats made from soft, chunked rubber (1/4", I believe they have 3/8 and 1/2 thickness as well).  It is supposed to be used to line the floor of horse trailers, to give horses traction and absorb shock (so it doesn't get absorbed by the horse's knees and ankles).  It is pretty cheap (like 2-3$ a linear foot, 4' or 5' wide rolls.

Title: Re: Motor Wiring
Post by: Enniberg on February 10, 2011, 10:07:41 AM
Great idea 3W! :applause:

I have a special mat, designed for use a trade shows and places where you need to stand in the same spot for a long time. It works extremely well, and since I am not doing a lot of trade shows these days, I am just going to cut out a piece to fit under the battery box. :dance:

Title: Re: Motor Wiring
Post by: StreamFixer on February 10, 2011, 06:39:16 PM
The stall mats I have worked with are pretty dense and do not do much for the light weight stuff we are dealing with.  I have 3/4" stall mat in the back of my truck to protect the bed and gate.

Title: Re: Motor Wiring
Post by: GoodDays on February 10, 2011, 07:13:51 PM
street hockey pucks should be just about right..and not too expensive... I still dont like the idea of having a battery in the cuddy but I guess if its not a sleeping space....

GoodDays Greg :gone_fishing:
Title: Re: Motor Wiring
Post by: Enniberg on February 10, 2011, 07:36:47 PM
Greg, I agree with you that it is not a good idea to put batteries in the cuddy of a Ranger, especially if you are going to sleep in it.

The Chaser is different - cuddy is only big enough for gear storage, and it does not have the water tank in the bow. Filling the tank on a Ranger is enough already, unless you have very heavy engines on the back.