We did the "Lithium Ready" option two years ago when we ordered our 21C. We had a 19 with the standard dual 6V 220Ah and it worked well, but we were often pushing well past the 50-percent discharge per night and the stock "GoPro" charge controller we had really didn't support Lithium all that well so to convert the 19 would have involved a bit more expense in addition to the batteries.
The Lithium Ready package on our 21C seems to have worked out well. We went ahead and had Escape install two solar panels, and with the package they include the Victron charge controller which is a nice setup. Really, the only thing we found overpriced from Escape were the batteries themselves. If I were to do this again, I would order our batteries from either "Current Connected" or "Renology". Current Connected used to add a few years to the manufacturers warranty, but no longer do. However they do provide excellent customer support. I would not recommend doing what I did, which was ordering SOK batteries direct from the SOK USA website. We had an issue with ours and it was just a real hassle working with the factory rep. We finally got the issues resolved (we think) with our SOK's as the manufacturer installed a new BMS, but it was a real hassle. Next time we need batteries it will be through Current Connected. I did call and speak with them and they are very nice over the phone and knowledgeable.
There are two other issues I should point out if you go the route we did. First, when you get your batteries make sure you charge them to 100-percent prior to installing in the trailer. Second, if you are going to run two in parallel, ensure you follow John from Santa Cruise's wiring diagram. This will ensure that as you draw power you pull from both batteries and not the one closest to the main connection first. We did not do that initially and it may have contributed to some of the battery issues we had.
Overall, the batteries are easy to install. We used some "quicksilver metal corder bead drywall" from Home Depot. It is easy to cut with tin-snips and a 1/4-inch or 3/8-inch drywall screw (into the floor) will hold them in place on each side of the battery. I also purchased a tie-down strap for each one and used my drill to drill-out a slot on each of the corner bead pieces for the strap to loop through. There are probably better ways to do this as a drill bit is not the ideal choice for creating a "slot", but drilling several holes adjacent, then using tin-snips and finally a metal file I was able to easily create the correct sized slots for the straps. It works very well. (
https://www.homedepot.com/p/ClarkDi...er-Metal-Corner-Bead-Drywall-741339/203171469)
I'm not sure what the current options are from Escape, I know they used to offer the option for "pre-wired" solar, the idea being you just have to buy and install your own solar panels. My concern with that is I would think you will need "exact" instruction from Escape about where the pre-wiring is located so you don't have to drill more than one hole to find/connect to them.
Good luck with your decisions!
