If the converter is original, its lucky to have more than a 3 amp output for charging. The old converters were not much more than a power supply, designed strictly for supplying power to the 12v items while hooked up to shore power. They were not a battery charger,...except for a few amps to maintain the battery.
The new converters are a power supply/battery charger. They are kinda smart, but they don't know or care if their amps are going into a discharged battery, or directly into the 12v distribution load. The amps will go where the lowest voltage is, either the battery, or the 12v system, maybe both.
If you are going to camp off grid, you need a genset, and a good 3-4 stage converter charger. Solar is great, but unless you have lots of it, and lot of battery, you can't depend on it all the time.
Rich
'01 31' Rexall Vision, Generac 5.5k, 1000 watt Honda, PD 9245 conv, 300 watts Solar, 150 watt inv, 2 Cos 6v batts, ammeters, led voltmeters all over the place, KD/sat, 2 Oly Cat heaters w/ ox, and towing a 2012 Liberty, Lowe bass boat, or a Kawi Mule.