Moved battery up front, now slow cranking...

Tucker99

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Gents,
I installed the battery in the front of the boat (14' Mirro-craft). I have about 16' of #4 cable going to a buss bar for the ground and a battery switch for the positive. I also have a fish finder and bilge pump on the battery switch and ground buss. The FSM calls for a 350CCA battery and I have a 675CCA starting battery. The starter starts, but labors to turn over the engine. I moved the battery back to the stern and ran off the factory 5' cable and the starter works normal, so the problem is either my rigging or the battery doesn't have enough CCA. What size battery do ya'll think I should use? I'd Like to keep to a group 24 size. Thanks Guys...
 

gm280

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I concur with dingbat's assessment. You need a direct setup with the pos AND neg battery wires going to the starter. Without being there, I don't exactly understand the buss bar and how it is attached from the battery to the engine. I bet you if you touched the wires while trying to crank the engine, you will feel some heat being generated. And that is because that wire can't supply the needed current that the starter needs... JMHO!
 

Scott Danforth

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you are going to need something much larger than your #4 cable.
 

Tucker99

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Why would I need larger cable? The chart dingbat attached says, at 30-amps, I can go 20-30 feet, I'm going 16 ft.
 

dingbat

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Why would I need larger cable? The chart dingbat attached says, at 30-amps, I can go 20-30 feet, I'm going 16 ft.
First off, length is both ways so your looking at 32 ft.

Second... only a 30 amp starter? Probably closer to 80 - 150 amps. Otherwise, why would they require a 335 Cold Cranking Amp battery?
 
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charly1954

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Why would I need larger cable? The chart dingbat attached says, at 30-amps, I can go 20-30 feet, I'm going 16 ft.

did you use CCA(copper clad aluminum) or OFC wire. Allot of people selling wire do not advertise its CCA. I didn't know there was a difference until last year my trolling motor extension wire "MELTED". I used the right gauge according to MK extension wire chart but found out later it was CCA, that's why it melted.

Found this online comparing CCA and OFC wire. CCA has more resistance than OFC.

When measured by equal cross-sectional area, electrical grade aluminum has conductivity which is approximately 62% of electrical grade annealed copper. However, when compared using equal weight, the conductivity of aluminum is 204% of copper
 

dingbat

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did you use CCA(copper clad aluminum) or OFC wire. Allot of people selling wire do not advertise its CCA. I didn't know there was a difference until last year my trolling motor extension wire "MELTED". I used the right gauge according to MK extension wire chart but found out later it was CCA, that's why it melted.

Found this online comparing CCA and OFC wire. CCA has more resistance than OFC.

When measured by equal cross-sectional area, electrical grade aluminum has conductivity which is approximately 62% of electrical grade annealed copper. However, when compared using equal weight, the conductivity of aluminum is 204% of copper
I’m not aware of any CCA wire that is tinned and approved for marine use
 

charly1954

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I'm no electrician but found this Amp rating comparison of CCA and OFC wire. It may show why OP has a problem if they used CCA wire. Nowdays allot of what is sold is CCA wire and not solid copper.

If I understand the chart below right, 8g copper(197°F) amp rating is 55 while 8g CCA(197°F) amp rating is 45. the 6g is a bigger difference with Copper 75amp and CCA 55amp.

https://www.alanwire.com/technical-d...nversion-chart
 

Scott Danforth

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Why would I need larger cable? The chart dingbat attached says, at 30-amps, I can go 20-30 feet, I'm going 16 ft.

you should really google starter in-rush current. the initial hit is probably closer to 200 amps prior to it dropping down for steady state cranking. the solenoid alone will pull about 40 amps just when it hits. the "chart" that dingbat posted doesnt have starters. you need to look at the starter manufacturer for in-rush current and steady-state current

for a total run of 32 feet, I would be running 0 or 00.... and if you use the calculator that dingbat posted as the second link, you would have known that.

but what do I know, I only designed engine installations for about 20 years.... if this was an I/O, the battery cables would have been 0000 minimum, most likely 350 MCM.

with your 32 foot run 4 gauge, my bet is the voltage at the starter during cranking is under 10 volts, probably closer to 9 in-situ

that is why you need a bigger cable.

4 gauge is for the stereo
 

charly1954

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I’m not aware of any CCA wire that is tinned and approved for marine use

Not sure why you quoted me. Don't see anywhere where I said CCA wire was tinned or approved for marine use. I'll never use CCA wire again, setting in the boat smelling melting rubber and then seeing smoke and it being melted is not fun.
 

dingbat

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Don't see anywhere where I said CCA wire was tinned or approved for marine use. I'll never use CCA wire again, setting in the boat smelling melting rubber and then seeing smoke and it being melted is not fun.

Being a bit facetious......the point being that CCA wire is not approved for approved for marine use.

Circuits that are properly fused don't smoke or melt....
 

charly1954

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Being a bit facetious......the point being that CCA wire is not approved for approved for marine use.

Circuits that are properly fused don't smoke or melt....

No to being facetious, but I sense a little hubristic in you post. Only posted a few times in here I come to the conclusion you may like to argue, so I'm not gona bite.

But I do have to say sorry but you are wrong if you're talking about my wire getting hot and melting. Take note, a properly fused wire can melt, that is what happened to my wire because it was CCA wire. By gauge it was what MK chart said to use but there chart does not specify not to use CCA. When I talked to them yesterday I told them they should put that in their wiring chart instructions. That the suggested wire gauge is for 100% copper not CCA.

On your 8th post for what you said there was no need to add my quote, I never said CCA wire was tinned. So if my post don't have anything directly to do with your comment please refrain from adding them to your post.
 
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Tucker99

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Ok, I'm back on this project replacing the #4 cable with #2. This is in an aluminum 14' row boat with bench seats. I was using 1" PEX pipe under the seats along the sides as a chase but that is way small for #2 cable. I was thinking 1-1/2" PVC pipe but that has 2" OD. Can anybody think of a good cable chase to protect the cable?
 

Tucker99

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Jun 9, 2011
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Ok, I'm back on this project replacing the #4 cable with #2. This is in an aluminum 14' row boat with bench seats. I was using 1" PEX pipe under the seats along the sides as a chase but that is way small for #2 cable. I was thinking 1-1/2" PVC pipe but that has 2" OD. Can anybody think of a good cable chase, that isn't so big, to protect the cable?
 

Scott Danforth

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Why not just use cable ties with screw eyes and simple secure the cables ever foot or so?
 
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