Compass Battery Question

[Mack]

I asked this question before, but I want to ask again this time with a picture.  I currently have my battery under the companionway because it is the most convenient for taking in and out to charge.  It's a big battery because I use it for the trolling motor.   I am worried that it is going to interfere with the compass.   Not many other options, so I wanted to see if you thought this could cause a problem.    I am about to pull all the wiring out of the compact 16 and put new wires in it.  Placement of the battery is the only thing holding me back right now.




thanks

Mack

[Bob23]

In my opinion, the battery is way too close. I understand a minimum of 2 feet is best but if it were me, I give anything electrical including wires a min1mum of 3 feet.

Bob23

[crazycarl]

mack,

pulling the battery out after every sail is a pain.

i have 2 batteries mounted up front in our 19.

i also mounted an automatic 10amp dual battery charger.

when we come home from a sail, all i have to do is plug it in.

when the cells are fully charged, it shuts off.  about $120 from bass pro.

cc

[mikew]

Mack, The compass is really only sensitive to metals like iron and steel. The battery by itself and the copper wiring with all electrical items
switched off on the boat shouldn't be a problem.
But there is a problem with the copper wiring as current passes through it, generating a magnetic field as these items are turned on. The more current a device takes, the more of a field develops and the more of a possible compass error.  
So maybe note a direction on the compass. Add the battery by itself see if there is any error. Then turn on your electrical loads- lights,
trolling motor, sounder and note the compass error. I understand the need to keep the wires short as possible to the trolling motor ( its safer and you lose less power in the wiring ), and have a convenient location for the battery, so maybe relocate the compass if needed.  
Mike

[skip1930]

So this is in a CP-16. How many of you guys and gals made electric motors out of a cork, nails, and wire in grade school?

The battery as stated and in location shown ought not be a problem.

The wires + and - to power the lamp in my opinion can be a twisted wire feed.

The two wires clamped into a vice and spun tightly together using a drill motor should cancel the magnetic influence on the compass.
Once this wire loom is spun-up and cut to size solder it in. Can also use crimp ends too.

skip.

[Mack]

Thanks for the replies.  I power a trolling motor off of it, so that might screw with the compass.  But usually when sailing, the only thing being powered would be the lights.   It is just the most convenient way place to put it, but probably not the best.   

The battery is quite heavy and taking it in and out is not fun.   I guess I can build a holder for it near the bulkhead in the bow and place it there.  It means a longer run for the trolling motor cable, but a shorter run for the rest of the wiring and it won't interfere with the compass.

I have thought several times about the Bass Pro solution, and quite frankly it is the one that i want! lol.  However, the boat is not kept at home usually because it so hard to get it into my hilly driveway that I keep it at the marina on its trailer.   So, I wind up taking the battery out to charge it between sails.  If I didn't have the trolling motor, I would put a smaller battery up front.

Mack

[cas206]

I picked up a U1 sized battery to run the lights on my CP16.  I found that this just fits under the forward hatch.  However, while researching battery sizes, I've learned that one advantage of the sealed Gel batteries is that they can be installed on their side.  So using battery width as your limiting height increases your choices for battery size.  Just FYI.

[philb Junkie19]

I moved my battery from the bow to under the companionway also. There is no shore side power where I dock the boat and no solar power yet. Th tillerpilot is the main draw down on the battery and yes it sure is a pain to wrestle a deepcycle battery from up in the bow compartment of a 16II. I also moved the the fuse / switch panel from the forward bulkhead to inside the companionway. It's so much easier to just reach in and switch on lights or power to the tiller pilot outlet when single handing.  Right now my compass is mounted on an extra companionway slide.  Guess that's close enough to the panel that I need to go back and twist up the wires, duh. I could mount the compass to port of the companionway although that's nice to lean against.  With the battery in the new location I replaced the port side berth cushion with a short cushion and the seldom used portapotti now fits under the cockpit seat on that side.