extension battery leads for onboard charger?

I have a Minn Kota 315D, 3 bank charger I want to put on a 20 ft. pontoon boat. Two batteries at the back and one up front. If I put it under the console to keep it out of the weather I'll have to have extensions on all three leads. I can probably figure out a way to put it closer to the back but that will mean a longer run to the front. The owners manual says it can be done if you splice the wires between the fuses and the fork in the output cable but I have seen where people have problems with it after doing this. Anyone have any experience with this?

Would it be better to just move the other battery to the back and run some heavy wire to the front for the trolling motor and depthfinder?

Two sets of wires on my three bank have been spliced and extended about three feet with no issues. If you do splice them be sure to use a wire heavy enough to carry the amp load for the distance you're running.

The easiest way to splice is to get stainless bolts, nuts, washers and lock washers, and connect your charger lead to a section of wire with ring terminals on both ends with that. Put heat shrink over the connection. Protects your charger warrant too.

Wouldn't soldering the splice followed by heat shrink be better? That's what I normally do. Just wondering.

My buddy has a 20 footer. Cranking battery in back, 2 trolling batteries in front. Charger mounted on back wall outside just above cranking battery. Wires spliced just like CatFan said and run to batteries in front. Been like that for 2 years with no problems.

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Originally Posted by Tracker123

Wouldn't soldering the splice followed by heat shrink be better? That's what I normally do. Just wondering.

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Better, yes, but you void the warranty on some chargers doing that. The nut and bolt splice works fine and doesn't cause issues with warranty.

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Originally Posted by cray

My buddy has a 20 footer. Cranking battery in back, 2 trolling batteries in front. Charger mounted on back wall outside just above cranking battery. Wires spliced just like CatFan said and run to batteries in front. Been like that for 2 years with no problems.

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Thanks everyone for the ideas. Been looking for the dual wall, adhesive lined heat shrink like the manual reccomends. All I have found is the cheap stuff.

cray, does your friend have anything protecting the charger? I like the idea of mounting it outside near the back. I keep it covered at home but it might get rained on at the lake.

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Originally Posted by hawkman

Thanks everyone for the ideas. Been looking for the dual wall, adhesive lined heat shrink like the manual reccomends. All I have found is the cheap stuff.

cray, does your friend have anything protecting the charger? I like the idea of mounting it outside near the back. I keep it covered at home but it might get rained on at the lake.

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No, it's right out in the open. Like I said it is mounted on the back wall out side just above his cranking battery. I don't necessarily agree with that but they are supposed to be waterproof and it is under the edge of his cover when at home. I might try to build a box from aluminum to cover it but leave the bottom open for cooling. Holding heat in will do more damage than rain. Without knowing the layout of your boat it's hard to recommend anything.

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Originally Posted by cray

No, it's right out in the open. Like I said it is mounted on the back wall out side just above his cranking battery. I don't necessarily agree with that but they are supposed to be waterproof and it is under the edge of his cover when at home. I might try to build a box from aluminum to cover it but leave the bottom open for cooling. Holding heat in will do more damage than rain. Without knowing the layout of your boat it's hard to recommend anything.

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The term "waterproof" has no legal or practical definition unless followed by an IP code. IP Code - Wikipedia, the free encyclopedia Waterproof can be as basic as resisting drizzle falling vertically.

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Originally Posted by hawkman

Thanks everyone for the ideas. Been looking for the dual wall, adhesive lined heat shrink like the manual reccomends. All I have found is the cheap stuff.

cray, does your friend have anything protecting the charger? I like the idea of mounting it outside near the back. I keep it covered at home but it might get rained on at the lake.

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I use these folks. Not the cheapest, but honest.

Heat Shrink Tubing and Tape