Solar panels for battery charging/tending

[BigClay]

I am absolutely ignorant when it comes to solar powers so I can here for the expert advice.

The battery in my camper keeps dieing (it is a newerish battery about a year old). I keep the camper in an area with no access to electricity so I am looking into solar. What is a good solar battery tender I could use to keep the battery charged? I don’t plan to use the solar to run anything, I just need the battery to stay charged to allow me to put out the slide so I can get in the camper (this is a truck bed camper = small and tight)

 

[WillnFox]

Something as simple as this will work:

12 Volt Amorphous Solar Panels Twin Pack, 1.5 Watts | Northern Tool

This Solar Panel Twin Pack Battery Maintainers allow you to maintain the 12V battery in your car, SUV, boat, ATV, personal watercraft and more usin...

www.northerntool.com

But you've got to have sun light #1 , but any thoughts on what is draining the battery?

 

[ponykilr]

The harbor freight ones go on sale for under $10 sometimes. I have left it in the rain some and it keeps my wood splitter battery charged with no worries (it stays in the back of my pasture). I’m sure there’s better but at the price they’re great.