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dockmasterdave's avatar
Aug 01, 2020

What ga wire do I need ?

I currently have a WFCO 45 amp converter. I have never been happy with it.
I have a voltmeter that tells me it is almost always at 13.6 volts. It never drops below that and in 8 years I have only seen it hit 14.4 once. I e mailed Randy at best converter a while back, and he suggested replacing it with a PD 55 amp wildkat. I bought that one and it came yesterday.
The instructions say " DO NOT " replace a converter with a higher amperage one.
I was hoping that the factory might have used a heavier wire than necessary, just to simplify their stock by using the same wire they have for a larger unit.
I checked my wires and they clearly say 6 AWG.
Does anyone know if #6 AWG is sufficient to handle 55 amps to a 2 battery bank at 20' ?
Thanks for any input. If I needed to run heavier wire, I can get at everything to do that. I just figured there must be a formula for amperage at a certain distance and wire gauge, and if any would know, it would be someone on here.
  • #6 is fine with 55 amps. If you pull wire I believe #4 is the max that will fit the connectors. You may also want to check if you have a fuse or breaker near the battery to verify rating. The PD will charge like a rocket when needed and consistently drop to storage voltage when expected. Make sure the jumper is in the lead-acid position, not lithium. Ampacity with 105C insulation is 100 amps for #6 but it is usually the voltage drop that becomes the size issue. Either way you are fine for now.

  • I have no idea what all the abbreviations mean on most of the ampacity charts, such as THHN THWN etc. However I did find an oversimplified one (below ) and based on this chart and others I am guessing between 65 and 75 is the amp rating. I would still like to hear from someone who knows more than I do and understands all the abbreviations etc.

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