Ok Brian……..you asked for it!
Proper battery charging is a science that has to accommodate more variables than any converter/charger (yes, even the Boondockers, Intellipowers and IOTAs which are 'dumb' compared to a quality inverter/charger like the made in USA Magnum Energy offerings) is able to deal with.
First, your charge voltage should be adjustable for the size of your battery bank. This is generally done by setting the time that the charger spends in the absorption charge phase (bulk, absorption, float).
Next, different types of batteries require different voltages for each charge phase to properly and completely get the job done. A liquid lead acid battery like an Interstate or Deka will require totally different charge parameters than a Lifeline AGM. Any quality charger should be able to set these charge parameters according to battery type.
Further, battery charge voltages vary significantly with the ambient temperatures of the battery being charged. The only converter/charger that does this is the Parallax Temp-Assure, which does not have a stellar reputation nor is it adjustable for the first two conditions. Quality inverter/chargers come with a temperature sensor probe that is connected directly to a negative battery lead (preferably one that is not directly conducting) to read the battery's temperature. This will allow the charger section to adjust the charge voltage up for colder temps and down for higher temps, according to the charger's internal charging algorithm.
Following these 3 requirements will give you the maximum battery life possible, assuming that you do not discharge your batteries lower than 50% on a regular basis, which will drastically reduce the number of available charge cycles.
Plus, with available remote control panels, you get to see current battery voltage, battery and internal inverter component temperatures and can also seamlessly add a full function battery monitor that reads thru a 500 amp shunt directly into the monitor panel…..no additional wiring required.
I have installed a few of Magnum's smaller inverter/chargers in primarily Airstreams where the folks do not even use the inverter section….they just like the increased longevity they will get from their battery banks now that they are fully and properly
charged. Plus, they can become the first in a series of building blocks to a full solar charging system with enhanced battery bank for extended boondocking.