Solar or Battery Tender?

Ratkity

The only thing I've heard so one shouldn't keep a camper plugged in is that it puts wear on the fan and converter. Anecdotal evidence (hearsay?) - I've not seen any other reports that it could be detrimental to the converter.

One person said if you have a lead acid flooded battery, to check the water periodically when the camper is idle and plugged in, waiting for its next camping adventure!  You don't want a dry cell in your battery.

Personally, I've done both - plugged in and solar. I've had two different LG campers plugged in for extended periods of time at home as I did my list of mods. I planned on solar and finally picked one solar setup, but there was a recall on the panel, so I decided to try a different solar system - suitcase panels for camping and a 20W trickle charge for the battery maintainer (kept on top of the propane tub). The reason the panel is 20W, is that I'm hoping it can keep up with the parasitic loads in the T@B. It'll take a bit, but I'll add to Jenn's and PXL's experience (and everyone else who use solar heavily).

Commercial float maintainers (the ones I've owned) can't keep up with the parasitic loads on the T@B (it's not immediately detectable, but your battery charge will sloooooooowly drop over time and needs a full battery charge periodically - I chose 1x a month for no particular reason before the 20W solar was connected). 

Answer to your question - yes. the converter a 3-stage battery charger (bulk, absorption, float) and the float stage can take a LONG time to get the battery up to 100%. If you want to use your camper for a weekend getaway, plug it in on a Tues and Wed. You can also get your frig (if you have one), nice and cold too.