What size ground wires needed

[Bisquick2]

PD9180L
Input: 105-130 VAC 50/60 Hz
1300 Watts
Output: 14.6 VDC, 80 Amps
Dimensions: 3.6H x 11.65L x 9W
Weight: 7.5lbs

I'm planning to install this charger and have it wired with 2awg to my batteries. Probably the 2awg was overkill since the batteries are right nexto to the charger, but they carry the 80amp without even getting warm.

I then run 8awg from my batteries to the dc fusepanel / power center (was existing wiring).

My questions are:

1) What gauge ground wire should I be running from the battery negative to the chassis? I'm thinking it should only need to be 8 awg since that's what's running to the power center, but I'm not sure. The distance would be 4-6 feet.

2) What gauge wire should I run from the converter charger box to the chassis? The distance would be approximately 4-6 feet.

Thank you

[Bama Rambler]

If you're running both positive and negative #2awg wires from the converter/charger to the batteries then you can use smaller wires from the battery bank to the power center. However, If you're using the frame as the negative then the wire to the frame needs to be the same size as the positive.

I would change out that #8 awg to #6 or #4 to the power center since you're going to the trouble to change the converter/charger.

[kcmusa]

Keep in mind other loads (jacks, etc) may not pass through the load center. I would go with a bit larger size.
Are there other positive wires off the battery?

[Bisquick2]

You’re right and I forgot about them because they are not directly on the battery post, but on the disconnect switch post.

There’s the tongue jack as well as the solar charger and maybe the tpms all on there.

As for the charger itself, I think it should be grounded to the chassis through A/C circuit panel. However, I’ll also be plugging it in directly to a generator, which I think means it needs to be grounded on it’s own.

[juice5]

If your using no 2 AWG off your battery then that should determine the conductor size for available fault current...and use penetrox on terminations encapsulating termination threads , conductors to wire jacket and to prevent oxidation and terminal heating

[camaraderie]

Are you installing lithium batteries or Wet/AGM's...the L in the model # you gave would suggest lithium and you could easily be putting 80 DC amps through to the batts, I would suggest a 4 gauge chassis ground off the batts,

Are you sure you'll be WIRING the converter to the generator. Most just take their power from the closest AC plug and don't care whether it is a genny or park receptacle that supplies the AC it need to convert. At 1300 watts input that is 11 amps of AC current so any household socket will work. Assuming your generator drives at least 1300 watts continuously...just plug it into your roo if it is external or run as usual if it is permanently installed.

[TitanMike]

My basic rule is to use the same size wire for connecting the battery to frame and frame to converter is a) Same size as largest wire in the CIRCUIT; b) largest wire size as you anticipate ever using between battery and converter.

Today you might want to use the existing (usual) #8awg wire but tomorrow you may want to upgrade the positive wire size. If so, you'll already have half the job done.

For most setups where the converter isn't next to the batteries the BEST wire size is the largest you can fit into the lugs at the Converter. One and done, regardless of future mods. Batteries will charge faster too.

[Bisquick2]

I will keep it simple and safe and run 2awg from the battery negative to the ground.

As for the other charger case ground to chassis, the charger will normally be plugged into a 20a AC circuit from power center. However, when I run the generator, which is located on the tongue, I didn't want to pull my shore power cord out and run it all the way from the rear of the RV to the tongue. I was thinking instead that I would wire an outdoor outlet right at the generator location to a new outlet located just next to the 20a AC outlet from the power center. This way, when I want to run the generator, I'll just reach in the front compartment and move the charger plug from AC power center outlet to the generator outlet. I know there are switches for doing that but they looked very expensive and it would be just as easy to unplug and plug the charger outlet.

Does this make sense, or am I planning this wrong?

So when the charger is plugged into the generator directly there will be no link to the AC power center chassis ground, so I think I need to ground the charger box. Since the generator breaker is 15amp, amd I wrong to just go with like even a 12 awg wire for the charger ground to chassis?

FYI, the generator is a Honda 2200.

Thank you