Your question appears to indicate you are looking for an off the shelf item to use solar to charge batteries. Before you purchase anything, you should determine what capacity you need based on usage. There is a day and night difference between a battery maintainer during storage and an actual charger to use while boondocking. Once you determine the capacity you need then you should start looking for components. If you are looking for something to maintain batteries during storage, I suggest starting with a 100 W panel and a 300W controller. the small 10-20W battery charger modules are worthless. What ever you end up deciding on I recommend getting a controller capable of 100-200% more than you estimate. This prevents purchasing a new controller if you decide to add panels at a later date.
2015 Freedom Express 248RBS
TV 2015 Silverado HD2500 Duramax
TST Tire Monitors
Honda 2000I + Companion
2 100W solar panels