Hi JShiv,
As you have already heard, you can charge AGM batteries with the converter-charger in your truck camper. If you share the make/model of the charger you currently have you may get some additional feedback regarding settings/jumper changes (if any).
Despite the fact that I'm a user and strong proponent of AGM batteries, I do not think that they are the best choice for most RV owners.
So, before you make the transition to AGM's, I suggest that you put some thought into why you want to use them….
AGM batteries offer some nice advantages over FLA's, such as; reduced ventilation requirements, the ability to be mounted on their side, very high charge and discharge rates, & long service life.
On the other hand; AGM's are much more expensive than comparably sized FLA's,they typically have lower capacity (per unit of volume), and are susceptible to damage due to venting as a result of over-charging.
If you reach the conclusion that AGM's are the best battery type for your needs, then I suggest that you also invest in a programable high-current 3-stage charger with temperature compensation so that you can reduce charge times and maximize both capacity and service life.
Cheers,
-Mark