Both factory batteries are Enhanced Flooded Battery (EFB) chemistry. They sit in between standard lead acids and AGM.
@MK898 posted a copy of the question he asked Ctek at post #484 specifically for his case where he has swapped out the auxiliary battery for a lithium battery. It's a bit confusing because he posted his question and Ctek's response separately. You need to read #484 and #485 together.
Ctek have reconfirmed the status of the red wire at the Smartpass 120S (where fitted). Connect it for lithium batteries. Leave it disconnected for lead acid batteries.