Lithium battery???

[MiniMe]

I have a 2010 TrailMini 18L. We need to replace the lead batteries and I'd prefer to get something where they can still be charged/topped off during storage with the shore power cable so that I don't have to pull the trailer out/open it to refill the water in the battery (read: maintenance free). I considered the sealed/gel type battery, but has anyone used a lithium RV battery? Pros/cons? What brand do you have?

Also, I noticed the lithiums are quite pricey, but if they perform better/last longer then it might be worth the cost?

Thanks!