Battery charging - more newbie questions

The built in converter/charger is a very capable unit. If your battery is partially discharged it will charge it much faster than the Amazon unit. It will also do an excellent job of safely maintaining a charged battery. No need for the Amazon unit unless you plan to take the battery inside for winter. 

Keep it plugged in.  Check the water level once a month.  Top up as needed.  Do not use tap water, used distilled water

If you live where it frequently gets very cold, then you should bring your battery into your house in the winter.  Your profile says you live in the Pacific Northwest.  If you're on the coast, and it rarely if ever gets below freezing, then you'll be fine doing what the others have suggested, and just leave it on the camper and maintain via the built-in converter.

However, if you live inland and experience cold winters, with extended periods below freezing, and perhaps even some single-digits or even below zero temps, I'd take it inside the garage and plug it into the maintainer you purchased. 

One other reason to consider taking your battery into your house:  How safe is your neighborhood?  Batteries are usually pretty easy to steal from campers, and can be tempting targets for thieves.  I'd be hesitant to leave my battery sitting out in the open for long periods of time like that. 

I agree on the freezing part. I believe Techntrek said a fully charged FLA battery would freeze at -98F or thereabouts. If it's that cold you have other problems. Leave it on the camper and keep it charged. However, that doesn't address the theft problem. If you're worried about theft you can 1) hire a guard 2) bring the camper inside, or 3) bring the battery inside as suggested 

thank you all again for your responses. I am most likely going to just detach the negative from the battery over the winter. I did that this past week and it conserved the battery level fine.  I am testing out the charging now and it seems to be working great from the distance with the extension cords so I'm going to return the trickle charger to Amazon. I can rebuy it later if need be.  I live in the Seattle metro area-- and even though we usually get a few cold spells each winter, most of the time the temps are above freezing.  I live in a very safe area and my Pod isn't viewable from the street. A lot of my neighbors have RVs and trailers too. I have a lock on the hitch and I can try to lock the battery up, but it's not a big concern. 

Thank you again for all your help and replies!!