Starter battery from the house battery

Hello,

I have a lithium battery in my campervan and then starter battery (acid). I want to charge my starter battery with my second battery when the voltaje of the starter battery drop below 12v.

my current setup is the following.

  • 2 x Lithium batteries non-victron brand
  • Victron Phoneix inverter 2000V
  • Victron MPPT
  • Victron Filax II
  • 3 x booster non victron brand
  • 12V charger non-victron brand

Then I have cerbo monitoring everything using Victron smarthunt.

what do you recomment to charge the starter battery? victron XS or Victron Orion-Tr Smart DC-DC?

Will it be possible to connect to the cerbo? will it be possible to set it up to charge the starter battery when the voltaje drop 12v? Thanks!