Originally Posted by Rickeoni
Charging a battery is like trying to fill a 50 gallon bucket with water. you can use a garden hose and with a steady flow it will eventually fill almost to the top before you have to slow the flow down. you can also fill way faster with a fire hose but only get to 80% full, before you have to seriously throttle back to get to 90% and then throttle back again for the last 10%. way quicker than the first way but it takes three stages. You could also do it the way most rv's are set up, try charging the batteries from a charger that is often 15 or more feet away from the batteries using undersized wires and trickle the flow into the batteries and you will also eventually fill the batteries to capacity, but it will take days to do it this way.
the careful fact that we are missing is a proper charger both in location and charging capabilities will get to the 80 & 90% charge stages much quicker with an efficient 3 stage charger which the WFCO has proven time and time again that it is not.
Like I said previously no one is right here and no one is wrong, just different avenues to get to the same finishing point.
Read up on battery chemistry and you will find that is a rather bad analogy put out for folks without a clue. Among other issues charging makes heat. The faster you charge the hotter the electrolyte gets and the better your chances of boiling the batteries. Not a good thing. That is why really high end quick chargers also have a temperature probe as part of the setup.
FWIW it sounds like the WFCO is in float mode most of the time so the batteries are not that low in charge. The only way to tell is with a hydrometer.
The other issue that needs to be understood is the internal resistances of the charger and battery along with the resistance of the interconnections will all work as voltage dividers in the system. It does not take much resistance to be an issue at 30 Amps of current flow. That is why current is a much better measurement than voltage when trying to determine how well a system is charging. System voltage will adjust to maintain set current limits. Charger current is limited to avoid eating the rectifier and transformer. The more control a system has the more regulation components involved that need protection.
Just for grins do a little math. 30 Amp x 0.01 Ohms = 0.3 volts drop. I have seen that much resistance in "good" connections. Messing about with low voltage high current is a bit of an esoteric set of tribal knowledge different than messing with 120 VAC or messing with high voltage low current. Each type of circuitry has it's own issues to deal with.