There are some things called alternator to battery chargers that can do this but I have no experience of them, Victron do not make one and all my experience is with Victron kit. The Victron Orion units are battery to battery (B2B) chargers so you need to keep a lead acid on the alternator output. Reports from people who have tried to use one direct from an alternator report large voltage and current cycles as the alternator regulator has nothing to dampen / buffer the system and the B2B starts cycling aswell. The only way to reliably charge direct from an alternator to a lithium battery is using an external alternator controller such as a Wakespeed WS500 or Arco Zeus, quite involved and expensive. However, with batteries such as Fogstar with a built in BMS, if the BMS shuts off charge a voltage spike can occur (load dump), doing this is best with a battery system that communicates to the alternator controller to shut the alternator down several seconds before the BMS isolates the battery. Things become expensive with that type of battery, such as the Victron NG batteries and Voctron Lynx NG BMS. Going with the above post from @Jen-in-Wellies consider getting a battery with CAN Bus communication, a Victron Cerbo GX and Victron Orion B2B charger and Victron SmartSolar and you will be getting towards a system per the guidance note. The battery tells the Cerbo what charge voltage and current is required and set up correctly, the Cerbo controls the chargers to match what the battery calls for.
