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Mixed Battery Cables OK? (1/0 & 2/0)

Leodan

New member
I have a fishing boat, in Ecuador, with a pair of Yamaha 200HP outboards (circa 2007). Because of the open rear-deck, the battery cable are about 20' feet long (6m). It's getting harder to start the motors and the cables do appear to be corroded so I'm thinking its time to replace them. The old cables are 2/0 gauge but its impossible to find 2/0 gauge battery cable in Ecuador (I need about 80' of it). I can get 1/0 cable and I'm pretty sure that would be OK if not for the distance from the batteries to the motors. (It would be a major pain to move the batteries closer).

So here's the situation: I can get just enough 2/0 welder's cable in black for the negatives. But the only other cable I can find is red in 1/0 (a size down) - There's plenty of that. Now I'm thinking the best solution is to use the 2/0 black for the negatives and and 1/0 red for the positives. They don't match but I can't think of any reason why that would matter - It's just a simple circuit, no? The alternative would be to use red everywhere and label the negative cable with black PVC.

Am I OK mixing the sizes like this or should I use the red 1/0 throughout?

Thanks...
 
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There isn't any real problem in having mismatched cables other than the original problem that the thinner cable will have to carry a high current therefore getting hot and causing voltage drop. Another option might be to double up the thinner cable if you have a plentiful supply. This will give the same effect as a thicker cable.
 
There isn't any real problem in having mismatched cables other than the original problem that the thinner cable will have to carry a high current therefore getting hot and causing voltage drop. Another option might be to double up the thinner cable if you have a plentiful supply. This will give the same effect as a thicker cable.

Thanks for responding. It was a local "expert" who advised against mixing sizes. But I expect that's because he wanted to sell me all that red cable. Another "expert" had told me the existing cable was 2/0, so I just went and took a closer look and I see that the existing cable is actually 1/0! I should have known! That's why when I need a competent mechanic, I have to fly one in from the continent.:cool:
 
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