My boat came to me with a Centaur 50A charger. Amazing piece of gear. It is set up with a dedicated shore power inlet, to allow charging batteries anywhere in the world. I rarely use it (I have a 3kW Multiplus that is the workhorse), but I do use it on occasion.
Here is the issue. It is wired with #8 wires, about 10’ from the batteries (so 20’ round trip). I get a total voltage drop of over 1.2V, which is to be expected. As a result, I rarely get more than 20A of charge (if the battery is WAY down, I’ll get the 50A, but as battery volts go up, the voltage drop makes the Centaur think it is in Absorption (or even Float).
On answer, a clunky and still noneffective solution, is to up the wire size. At #4, the voltage drop is around .5V, much better but still a problem. It takes a massive #1 to get under .25V drop.
My current mitigation, which helps some, is to set the dip switches for “other,” which puts Absorption at 14.7 and Float at 13.7. This is really too high for my LFP batteries, but the BMS disconnects the Centaur (via a Battery Protect) at fully charged, and isn’t high enough to cause damage regardless.
The right answer of course is remote voltage sense. The unit does not appear to have this as an option (while it’s a slick piece of gear, it’s really rather basic/dumb). Is there anyway, on or off “label,” to get a sense wire into it? My alternators have battery sense, my Multiplus and SmartSolar have battery sense (via the bluetooth dongle), but I can’t seem to get the Centaur to do it.