[rickst29]

From 'moderately deep' discharge to full charge, the Coulomb Counter measured about 110ah - less than the 120ah I was hoping for, but not bad enough to demand a refund. After a couple of discharge-recharge cycles, the maximum charging capacity fell a bit lower (down to 100Ah) from roughly 10% SOC to 100% SOC.

While charging, however, the battery was willing to accept the entire maximum power output of the "55A" Converter. (And not just at low Battery State-Of-Charge: This 'fast' charging rate continued until more than 90% SOC.) The battery was fully recharged in barely 2 hours. And so, the notion of using #10 wire (30A) or even #8 wire (40A @ 60 degrees C) goes out the window. #6 will be required to do the job, for both "12V" positive and the grounding "-" return. Surprisingly, the Charge current was higher than advertised - about 65A.

I'll be running those wires underneath the TM floor, within 'liquid-tight' conduit. That is a highly insulated environment, which also contributes to designating #6 as the minimum requirement (even though the wire will be THWN/THN2 (capable of 90 degrees, 75A in a cerro-wire ampacity chart.). New Circuit Breaker size is 80A.