In this case a B2B charger will work fine. There are three key features to look for the charger:
1) Output of charger should provide a dedicated characteristic for charging lithium batteries.
2) Input of charger needs a detection circuit (wake up) to start charging, if there is energy available (from solar or alternator).
3) Sufficient charging power to bring the lithium battery up to full charge in time (this is depending on your energy demands drawn from your lithium batt/Inverter and the time when additional energy is available, no matter from which source )
For example a Victron Orion should do that job well, but there are other brands on the market too.
To provide proper function a diligent installation and setup of the charger is key.