FN-DC wire to battery bank

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FN-DC wire to battery bank

Postby stevetull on Mon Dec 04, 2017 3:45 pm

The twisted pair of wires from the FN-DC that are meant to go to battery + and -. The FN-DC manual says they must go to the positive and negative battery bank terminals. Can I just keep those wires inside the DC enclosure and land those at the other end of the battery cables? That means the positive wire would bolt onto the positive BBUS and the negative wire bolts to the negative BBUS (at the intersection of the three shunts).


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Re: FN-DC wire to battery bank

Postby Mike Curran on Mon Dec 04, 2017 4:36 pm

That's exactly what I did. My batteries are in two separate battery boxes but they're still all in series so my negative terminal is separate from the positive and the supplied FNDC twisted pair wouldn't work.

You would think that wiring the voltage sensing wires this way would result in lower than actual voltage readings, but I found the opposite to be true. Voltage I measured at the battery terminals with a DVM was actually lower than the FNDC indicated and I ended up placing a small variable resistor in series with one of the FNDC sense wires to adjust it downward to match actual at the battery terminals.

If you're using the heavy cables that are required for battery connections there normally won't be much voltage drop across that cable. I don't see a problem with what you're doing.
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