I tracked and charted out the wiring for my converter charger and batteries. I know some people get wiring diagrams, but here is a non-technical diagram including the lengths of the various cables. Why should anyone care? Well, if you want to improve your converter's charging performance, you will be dealing with voltage drops. Here is the stock wiring in my 2014 model 2300.
The converter is rated 55 amps. However it doesn't provide all those amps for battery charging in my experience. More like 20 amps. It's usually doing that at 13.6-13.8 volts. It is supposed to go up to 14.4 for bulk charging, but the programming is such that it never goes there for most users.
So let's look at some voltage loss calculations. There are calculators all over the net. Take these numbers as rough guides, because the negative side of the cabling includes the van chassis as part of the circuit, and those losses are not so bad, at least when the ground connections are good (not corroded).
At 14 volts and 20 amps, the voltage drops by 0.5v by the time it gets to the batteries.
At 40 amps it drops by 1.0v. At 55 amps it drops by 1.25v.
Why do volts matter during charging? Aren't amps what are put back into the battery? Volts are like pressure. If you are trying to fill a tire to 80 lbs, and your air hose is only putting out 85 lbs, you are in for a long wait. OTOH if your air hose is putting out 150 lbs, it goes quickly. If the volts are less than optimum, charging takes longer, sometimes a lot longer. Most stock converters are slow to begin with. Add the effects of long wiring and it becomes quite a bit worse. This is all over the RV industry, not just FR.
So you decide to install a better converter, say a Progressive Dynamics. In my case, if I swap in a PD converter trying to push a true 40-50 amps, I'm going to lose 1.0v or more by the time it gets to the batteries. This is why it matters.
When it warms up I'm going to test the volts and amps of my stock converter on a recharge. Then I'm going to re-do some cables up by the batteries and connect the converter close to the batteries, with larger cables, and test again. It might take me time to get around to it, but I'll post the results. At that point I'll see if I want a new converter as well. But I'm not sticking a better converter at the end of 28' of #6 wire.