For lithium you need to be more specific (li-ion, li-po, lifepo4)...
For vehicle use a safe chemistry to use is LiFePO4 (lithium-ferrous-phosphate). To extend the life you really should be using a DC DC charger that has a lifepo4 charging profile. I use a Wagan unit (25A max charging) that has both Solar (mppt) and Vehicle power inputs in a pretty compact form factor. As above, this kind of charger will automatically charge when the vehicle is running (or solar is present), simplifies wiring, sort of set and forget.
This kind of setup allows the lifepo4 to be fully isolated from the starting battery and can be it can be safely drained (I use an ecoworthy 100AH with built in BMS) thousands of times while maintain good lifespan.
cheers,
george.