You guys crack me up with your comments about the Magnatec 6300. It's neither a battery killer nor is there no "in between". I still have one (do you?) in my old '87 Fleetwood and it works just fine, thank you. Is is a linear model that has been replaced by modern technology? Of course. And I will ultimately replace/upgrade mine in due time, but it's not at the top of my list.
Apparently there's an option known as "Option C". From the original users manual:
Units with Option C contain an automatic, solid-state Battery Charging Section. When 120 VAC power is connected to Power Center, the Charging Section will automatically “sense” the condition of RV battery. If it is below “full charge,” the Charging Section will start charging the battery.
If RV battery has been drawn down quite low, it will be charged at a relatively high amperage rate. If battery has not been severely drained, it will be charged at lower amperage rate. The rate of charge will decline as the battery reaches “full charge”. After battery reaches “full charge”, the Charging Section will drop back to “maintenance” level. It will not resume active charging until battery again falls below “full charge”.
Mine must have this wonderful Option C because my batteries are just fine, after 4-5 years and have not been killed or overcharged yet.
How many had or didn't have this option, I dunno. But it seems these misconceptions about the 6300 series are the RV converter version of "Reefer Madness"