Author Topic: Power wire guage (Read 41318 times)

basszilla · « **on:** March 09, 2012, 03:11:33 PM »

What guage of wire should I buy to run the power wire to my battery?

George · « **Reply #1 on:** March 09, 2012, 03:20:58 PM »

basszilla

We really need to know a bit more what you are trying to do. For instance most trolling motor wiring to a battery is either 6 or 8 gauge wiring and this is depends on the length of wire required, the larger the wire the less the power drop. If you are going to a power panel, you need to know the length and and list the units with the power they require, I always opt to use at least one gauge over the calculated size.

So if have a description of wiring needs, someone will be help to determine the proper wire size, also when discussing wire for boats it is stranded copper wire, not solid copper wire.

George

basszilla · « **Reply #2 on:** March 09, 2012, 03:55:53 PM »

I'm trying to connect my 898c SI. Do t know whether to connect to the panel under steering or run power cable directly to the battery. I also have a regular depth finder on the console that is connected to the panel. I also have a bird on the bow also connected to the panel. The length of wire from the console to the batter is like 8 ft. There is room on the panel but I don't want to have interference. Any suggestions?

LocDown · « **Reply #3 on:** March 09, 2012, 04:00:02 PM »

I would try 16-18 awg from the panel. That should be more than enough for the 898. If you're concerned about interference, try to keep the wire routing clean and separated from the other wire runs.

Humminbird_Greg · « **Reply #4 on:** March 09, 2012, 04:23:24 PM »

I would use 14 AWG stranded copper wire straight to the battery. May be a little overkill here but better to have a heavier wire gauge than needed versus one that is not large enough and have problems. Be sure to install a waterproof fuse holder and new 3 amp fuse (I prefer the blade type fuses).

sonar2000 · « **Reply #5 on:** March 09, 2012, 05:42:50 PM »

Try not to use aluminum wire.....

Chuck

George · « **Reply #6 on:** March 09, 2012, 05:56:44 PM »

basszilla

As Greg states 14 gauge copper stranded wire connected directly to the battery is the best way to make the connection for the least amount of interference. Also, I would make the the connection to the starter battery (unless it is too small), I found I was getting more noise interference when connected to the trolling motor's battery.

George

basszilla · « **Reply #7 on:** March 09, 2012, 07:27:52 PM »

Thanks guys I'll keep you all posted on how my install goes. Keep an eye out for more questions as problems arise. Thanks in advance.

sonar2000 · « **Reply #8 on:** March 10, 2012, 10:38:17 AM »

Bass....lets hope they are questions and not problems....

Lots of good answers on the forum
Chuck

newkid4si · « **Reply #9 on:** March 10, 2012, 11:42:42 PM »

I'm with Greg on the 14 AWG stranded copper wire. Here's what I did. Went to Walmart in the extension cord area and they had a 25' outdoor cord with the 14 gauge stranded.
Brought it home and cut the ends off and now I have 24'6'' of coated wire. Stripping back a few inches of the red outer coating will expose three wires to work with. You only need two. Crimp and solder your connectors. You should be good to go. Much easier to feed into and around things that two separate wires.

sonar2000 · « **Reply #10 on:** March 11, 2012, 10:03:45 AM »

You can also buy two wire extention cords and not have to worry about the green ground becoming an antenna..

Chuck

newkid4si · « **Reply #11 on:** March 11, 2012, 01:17:54 PM »

Chuck
Good point. Did not consider the antenna potential. More focused on the outer coating and 14 wire,.... and it was on sale.

calli1 · « **Reply #12 on:** March 11, 2012, 03:02:55 PM »

As a past job of mine...electrician, the longer from point A to point B determines the size wire. If you are running to the front of your boat, go a extra size larger making sure no voltage drop between unit and battery. But I'm with Grag on this one also. Also, very important to run your wire for powering your unit just for your unit and might even help with interference if you ran on the size of the boat where no other wires are. So, Run 12 to 14 guage wire and for the unit only. I accually have mine on the starting battery.

Humminbird_Greg · « **Reply #13 on:** March 14, 2012, 01:40:30 PM »

Newkid4si did the same thing that we have done on both of my Wife’s Nephew’s boats. The outdoor extension cord was the only wires that the local Wally-World had in the 14 gauge size.

The standard PC-11 Power Cable for the larger 800/900/1100 series units (and also for the 798 units) is an 18 gauge stranded copper wire, so using a 14 gauge stranded copper wire is already going two wire gauge sizes larger.

sonar2000 · « **Reply #14 on:** March 14, 2012, 04:53:38 PM »

Make sure to use a 2 wire conductor and not a three wire cable..

Chuck

Humminbird_Greg · « **Reply #15 on:** March 15, 2012, 11:42:25 AM »

Quote from: sonar2000 on March 14, 2012, 04:53:38 PM

Make sure to use a 2 wire conductor and not a three wire cable..

Chuck

And why would that be Chuck?

Whistler · « **Reply #16 on:** March 15, 2012, 02:24:58 PM »

Yes, why would that be Chuck? I used a heavy duty 12 gauge extension cord (cut the ends off of course) and that worked great. I just taped off the unused third wire.

sonar2000 · « **Reply #17 on:** March 15, 2012, 03:09:00 PM »

for most of thewtime it will be fine to use a three wire cable. But there are times when the third wire could act as an antenna and induct/induce a spurious signal as in crosstalk.
A lot of this depends on how you choose to run the cable, where you run it and could some external signal be introduced.

Remember we are working with low volt low amp microchip computers now and it dont take much to cause an unwanted injection.

It all depends on how well you isolate the three wire cable and proximity to other radiating or oscillating current or RF..

Remember shielding (or lack thereof) issues we have seen before...
chuck

mendota · « **Reply #18 on:** March 15, 2012, 05:00:33 PM »

I feel I should caution everyone that the power cords that you are scavenging do not employ the technique of twisting the 2 wires together, which very significantly reduces the susceptability to external interference.

If you want the best setup, twist your power wires together, about 1 twist per inch. Use at least #14, and although HB recommends a 3A fuse, the fuse is solely for protecting the wire, not the unit, and a bigger fuse (10A for #14) together with the larger gauge supply wires will dramatically improve the voltage reading on the display.

Drives me crazy to see a fully charged battery (at least 12.8V) read 12.5 or 12.4V. I really wish HB had implemented an IR compensator for the voltage readout - the high current draw of the display backlight is really killing the ability to measure the battery voltage accurately.

sonar2000 · « **Reply #19 on:** March 15, 2012, 06:02:13 PM »

Mendota...Very good postings.
Electronic devices today are not what they were years ago.

You are so correct in the assessment of the voltage display using a current draw instead of potential for..What a great idea. something that makes reliable sense as far as power supply accuracy...
Maybe HB will consider this in future designs..
Of course then they will owe you a royality..

Thanks, chuck

Bob B · « **Reply #20 on:** March 15, 2012, 08:48:37 PM »

Quote from: mendota on March 15, 2012, 05:00:33 PM

I feel I should caution everyone that the power cords that you are scavenging do not employ the technique of twisting the 2 wires together, which very significantly reduces the susceptability to external interference.

If you want the best setup, twist your power wires together, about 1 twist per inch. Use at least #14, and although HB recommends a 3A fuse, the fuse is solely for protecting the wire, not the unit, and a bigger fuse (10A for #14) together with the larger gauge supply wires will dramatically improve the voltage reading on the display.

The twisted pair is a great recommendation for reducing interference. I work with building control systems, and we ALWAYS run twisted pair for that reason. If it is really critical, like communications wire, we use twisted shielded.....Only ground the shield at one end with shielded wire.
Should be able to create your own twisted wire as Mendota suggested.

As an afterthought, it would be a good idea to run twisted wire to the trolling motor also if there is a serious interference problem. The twist also reduces the radiated noise from the wire.

mendota · « **Reply #21 on:** March 15, 2012, 09:11:40 PM »

I need to correct myself a bit - the reason I recommended a 10A fuse is not because of the #14 wire, but because HB uses a #18 wire in the 6' power cord they supply with the 1197 (my unit).

I am comfortable fusing a #18 at 10A. However, older HB units, 997 on down, used a finer gauge power wire, I think #20. A 10A fuse might be asking for trouble with a #20 wire, so please disregard my fusing tip if you are not sure what you have. Perhaps Greg could advise here?

IR compensators are century-old technology, literally. In fact, all they have to do is map the current draw vs. the backlight intensity, build it into a table, and estimate the battery voltage given a typical fuse and wiring impedance. They would be within a tenth of a volt (probably better), even without any user input. It would take all of 10 lines of code, a few hundred bytes of memory.

Well Ok, maybe a bit more. Rant over, LOL.

Humminbird_Greg · « **Reply #22 on:** March 16, 2012, 04:42:19 PM »

Actually 22 AWG on the PC-10 power cable for the smaller units and the older Si units.

The last extension cord I used had twisted wires in it… maybe I just got lucky?

If I understood Bob B: if you use an extension cord you should ground one end of the ‘extra’ wire for better noise protection, right?
Never thought about twisting the trolling motor wires but this would be more than what most fishermen would be able to do considering that the power wires are usually run while the boat is being built.

I have not check the accuracy of the voltage readout in many years but I doubt that it would be very far off. It is meant to be used as an indicator readout and not an NIST standard guys.

sonar2000 · « **Reply #23 on:** March 16, 2012, 04:51:18 PM »

Yes by all means ground the extra wire.

Voltage indication: This should be an indication of a load and not a potential or rootmean. It would be nice to take into consideration a current flow and determine the value that way.
Just as mendota and Bob are indicating..
It would be nice to see a current flow indicater..but that would certainly increase the price of the unit..
bottom line is it is our responsibility as a user to ensure we have a fully charged and operational power supply..

Chuck

Gattlin · « **Reply #24 on:** March 27, 2012, 12:41:55 PM »

Ok Hmmm,, 14G stranded wire. twisted run on the Starboard side "opposite side of the harness" Water proof blade fuse at the battery,soldered connections with diaelectric , run to the bow. Question if there's a third wire in the run, ground to the boat or the battery on one end? Did I get that right? And with two HB units should I use another dedicated smaller battery for the second head unit at the bow? And also while I,m at it

Would one of those small gel batteries for my vexilar I use in winter power the 898c for a eight hour stretch? Ooops sry for so many questions I',m pulling the boat out of storage tomorrow and rigging

Thanks in advance

sonar2000 · « **Reply #25 on:** March 27, 2012, 12:53:21 PM »

If you have a three wire cable it wont hurt to run two grounds and one power..
Also most boats dont have a frame grounds as they generally are not made of metal..
It will not hurt to run a second batter for the bow unit and located near the bow..
The amount of storage amps in the battery provide the amount of run time...More amps longer run time..

Chuck

Gattlin · « **Reply #26 on:** March 27, 2012, 02:17:13 PM »

Thanks Chuck that's a better idea putting a battery up in the cubby hole in the bow saves a lot of rigging and wiring hassle.

sonar2000 · « **Reply #27 on:** March 27, 2012, 05:28:56 PM »

Since it will not be hooked to the motor charging system..
it might be a good idea to make sure the front battery is easily accessable or have a quick way to put a charger on it..

Chuck

Patty · « **Reply #28 on:** April 07, 2012, 12:33:42 AM »

Okay... I have a couple questions relating to this, I installed my 898c si last spring and have had very unusual voltage readouts.... I'm wired into the power panel on my Javelin, i just spliced into the wiring from the 997c that was on the boat... But even on fully charged batteries i get low voltage (8-10v) readings on my unit unless my outboard is running at more than an idle, then it will read 12-12.8v until i shut off the motor, once its off its immediatly down to lower readings... So my question is... will running direct off my battery as described in the earlier posts here potentially fix this? or do i have a entirely different can of worms here? Any thoughts or input on this would be great help!!!

Thanks

Patty

sonar2000 · « **Reply #29 on:** April 07, 2012, 12:12:51 PM »

Patty, it has been shown that having your unit on its own power source greatly improves the operation.
As with any battery a regular load test of the battery is a good maintenance procedure.

Chuck

Bob B · « **Reply #30 on:** April 07, 2012, 02:55:33 PM »

Wired direct to the starting battery or to a separate battery just for the electronics is always better than going thru the boat power panel. Every connection has the potential for increased resistance and more voltage drop.

It is hard to tell with your situation if you are getting voltage drop from the wiring or just have a weak battery. You would have higher voltage when the motor is running because the charge voltage is higher than the normal battery voltage. You are definitely getting lower voltage than you want to see at the unit if you are seeing 8-10V when the battery should be full charged.
If you load test the battery and it is good, then you are loosing power through the connections or wire resistance.

If it were me, I would wire direct or have a separate battery for the electronics regardless of what you find out with your battery. It will save you problems later. I would use at least 14 guage twisted pair standed wiring for the power. 12 guage wire would be even better, and would give you extra capacity if you want to connect more units later...stranded is more durable and twisted will ruduce the possibility of interferece.....If you pull in wire, pull an extra pull string for future use.

It may be posted above, but you can create your own twisted wire by laying the 2 wires out, connect one end to a solid object and put the other end in a drill chuck.....twist it while gently pulling on the wire.

sonar2000 · « **Reply #31 on:** April 07, 2012, 04:28:48 PM »

A 2 wire cable is best but sometimes a three wire cable is what is bought.
If you use a three wire cable make sure to ground the unused wire so that it does not act as an antenae..

Chuck

Patty · « **Reply #32 on:** April 07, 2012, 04:32:31 PM »

well i think my battery is good its brand new but i haven't tested it yet... but i did buy a load tester, some 14/2 stranded wire, a whack load of connecters etc today... I'm hoping going direct will help solve my problems... The wire i bought is not twisted it has a flat profile but its not like trailer wire, both wires are coated individually and then coated again, i probably wont be able to twist these will I?

sonar2000 · « **Reply #33 on:** April 07, 2012, 04:38:28 PM »

With a good deal of work you could twist but for now I would just wiren it direct and away from other wires when possible..

this should help you a lot with a dedicated supply..

Chuck

Patty · « **Reply #34 on:** April 07, 2012, 06:27:07 PM »

okay... lol i went and found twisted stuff... now just to get it all wired up....

Bob B · « **Reply #35 on:** April 07, 2012, 06:45:58 PM »

Make sure you put a 3amp spade type at the battery end. Get the best connection to your battery that is possible....clean all corrosion.

Hope this fixes it for you.

Patty · « **Reply #36 on:** April 10, 2012, 03:21:09 PM »

Well i got it all wired up, had a heckof a time fishing the wire through the boat but eventually got it... I crimped and soldered all the connections and put heat shrink tubing on them, went with a 10amp fuse couldn't find a 3amp bladed... tested my battery it read 13.40 volts, hooked it all up and now my 898 reads a consitant 13.1 volts so i'm thinking i got that issue fixed... I forgot to unplug my charging system while doing this but everything was fully charged and it read inconsistantly before even when hooked up o the charger... thanks for all the info in this forum guys!!!

Bob B · « **Reply #37 on:** April 10, 2012, 03:48:35 PM »

Glad you got it resolved.....You should be fine with the 10 amp fuse. It is there to protect the wire / battery not the unit. Looks like you did a really good job...only .3 volt drop now. You will have a much happier unit now.

Whistler · « **Reply #38 on:** April 10, 2012, 05:08:27 PM »

Quote from: mendota on March 15, 2012, 05:00:33 PM

I feel I should caution everyone that the power cords that you are scavenging do not employ the technique of twisting the 2 wires together, which very significantly reduces the susceptability to external interference.

Just an update, I just ran a 14 gauge 3-wire outdoor extension cord (it was red) from Walmart as the power supply for my 798 at the front of my boat. The cables in that extension cord were, in-fact, twisted rather generously. Taped back the unused 3rd wire and it works like a charm.

Patty · « **Reply #39 on:** April 10, 2012, 05:26:42 PM »

I found 14/2 stranded wire cord at Home depot, I guess its for building extention cords and it too had a pretty good twist to it...

RV Sam · « **Reply #40 on:** April 11, 2012, 12:24:16 PM »

All this and not a mention of using Marine Tinned Wire

? Or, because this is about mounting these on a boat it goes without saying ? But those home use extention cords have me lost.

Humminbird_Greg · « **Reply #41 on:** April 11, 2012, 01:27:00 PM »

The best set up would be a marine grade multi-stranded copper wire that is soldered and sealed at all connections with a non-corrosive additive on the connectors. I doubt that most fishermen out there have access to these things or want to spend that much either. Extension cords are cheap and available though and so are hard to beat.

RV Sam · « **Reply #42 on:** April 11, 2012, 01:59:15 PM »

It's not the sealed issue, it's copper wire issue. Untinned copper even inside the rubber casing will first turn green, then get brittle, then break, then disappear. Any wire will work for a few years and in most cases longer. But to do it and forget about it and not give problems to someone down the road, err,, I mean water, why not do it the correct way. Not trying to be a smart a**, just thought it should be mentioned.

sonar2000 · « **Reply #43 on:** April 11, 2012, 02:08:51 PM »

I guess it all depends on what you are going to expect from your unit.. Today (new) and down the road (used).
How much maintenance can you do and what problems will you live with later..

Chuck

Humminbird_Greg · « **Reply #44 on:** April 12, 2012, 05:14:43 PM »

Good point RV Sam and Chuck is right. I agree with doing it right the first time but I don’t think that most want to go to the time and expense to do so. I’ve worked on many boats and at least from the small boat perspective: it isn’t worth the time and effort for a long term fix. Most do not even do preventative maintenance as it is. Must be the day and age we live in…

sonar2000 · « **Reply #45 on:** April 12, 2012, 05:51:49 PM »

We only spend that which we have at the moment.
We dont look for the savings in later life.

It is not only boats or sonar or gps. We skimp on every thing today..

Chuck

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