I have Lithium batteries. Did a lot of research on this. My converter is a
Progressive Dynamics, model PD4575K18LS8.
It will work on lithium batteries BUT I will not get a 100% 13.6vdc charge. I can live with that.
https://www.etrailer.com/RV-Converte...575K18LS8.html
Works on LiFePO batteries also
https://www.etrailer.com/question-354675.html
Lithium converter PD4575(LI)
https://www.progressivedyn.com/lithi...acement-units/
Here is a good article on Lithium batteries
How to find happiness with lithium batteries
https://www.solacity.com/how-to-keep...tteries-happy/
Your converter model number will be on a label inside the fuse panel