Let us know what type of trailer and what kind of converter you currently have. There is a lot that goes into managing a battery so we need more information.
There are one stage converters (not inverters) that charge batteries at the same rate all the time. When the battery is charged the converter continues to charge which over charges and will destroy a battery in short order.
" I have had issues with dead batteries while boondock camping. I have done current draws and I'm not getting anything but I keep having to replace my batteries and I am using the deep cycle marine units."
You have had to replace batteries in the past. How often does this happen? If you let a battery go dead then it will never be able to hold a full charge. Maintaining the battery requires checking the water levels in the cells and careful charging and attention.
Get a good deep cycle battery that does not have "marine" on it. A marine battery is for boats and needs to be able to crank the engine. A deep cycle does not have the cranking amps requirement. They are different beasts.