I want to do it right and am not afraid to dig in (do the work and spend the money).I've got a Progressive Dynamics PD 4645 converter (which I put in to replace a boiler type).The length of cable from the battery to the converter is 12 feet. I am supposed to double that length to look at charts for the correct gauge, right?The gauge of the wire in there now is 8 AWG. Some of the places I look say that's OK, some say 6 AWG, and some say 4 AWG.What do you recommend, why, and what is your source?Thanks very much.

Assuming that's a 45a converter, I'd consult an ampacity chart for wire size.

6 gauge would work.I would go with #4 for both positive and ground.

This is a good one which uses a 'set' so it is the one- way distance you enter. Just change the wire gauge entry to see what happens with each gauge.http://www.calculator.net/voltage-drop-calculator.html?material=copper&wiresize=0.8152&voltage=14.4&phase=dc&noofconductor=1&distance=12&distanceunit=feet&amperes=45&x=60&y=6

Winnebago installed a 45 amp converter in my RV with 8g wire with a run about 50% longer than yours.That said, I upgraded to a 55 amp converter and 4g wire, but that was just my personal choice. It was overkill but reduces voltage drop and doesn't hurt anything.ON EDIT:I just surfed a bunch of websites that recommend wire sizes and the results seem to be:8g - safe but significant voltage drop and poor charging performance6g - good choice4g - great choice because it reduces voltage drop significantly for best charging if you boondock a lot.

#8 is fine. If pulling wire go #4 as the cost is not huge and it will fit the connectors.Source is personal experience.The more you charge with a generator the more I recommend the larger wire.If on utility power the #8 is fine.afaik the most you will see for an extended period is about 40 amps with a 45a rated PD.

What gauge wire? | Good Sam Community

Too_Tall
Explorer
Nov 09, 2013
It depends on how many amps you are pulling. If your load is only 20 amps than a lighter gauge is fine. Make sure you use new connectors.
time2roll
Nomad
Nov 09, 2013
#8 is fine. If pulling wire go #4 as the cost is not huge and it will fit the connectors.
Source is personal experience.

The more you charge with a generator the more I recommend the larger wire.
If on utility power the #8 is fine.

afaik the most you will see for an extended period is about 40 amps with a 45a rated PD.
Bobbo
Explorer II
Nov 09, 2013
Winnebago installed a 45 amp converter in my RV with 8g wire with a run about 50% longer than yours.

That said, I upgraded to a 55 amp converter and 4g wire, but that was just my personal choice. It was overkill but reduces voltage drop and doesn't hurt anything.

ON EDIT:

I just surfed a bunch of websites that recommend wire sizes and the results seem to be:

8g - safe but significant voltage drop and poor charging performance

6g - good choice

4g - great choice because it reduces voltage drop significantly for best charging if you boondock a lot.
BFL13
Explorer II
Nov 09, 2013
This is a good one which uses a 'set' so it is the one- way distance you enter. Just change the wire gauge entry to see what happens with each gauge.

http://www.calculator.net/voltage-drop-calculator.html?material=copper&wiresize=0.8152&voltage=14.4&phase=dc&noofconductor=1&distance=12&distanceunit=feet&amperes=45&x=60&y=6
enblethen
Nomad
Nov 09, 2013
6 gauge would work.
I would go with #4 for both positive and ground.
2oldman
Explorer II
Nov 09, 2013
Assuming that's a 45a converter, I'd consult an ampacity chart for wire size.

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