Replace factory second battery to DC/DC

[roadtripper]

Would that include a BM2 monitor?

It would be best to follow best practices with that as well if practical, but a more important reason not to wire them directly across the battery terminals as delivered with the usual BM2 units is making sure they are fused.

Otherwise you have two unprotected wires uncomfortably close to each other right across the battery.

 

[jgm0]

I'm part way through doing exactly what you are looking to do. I've already got the Victron Orion XS 50 DC to DC charger in and working in place of the split charge relay. I've just replaced the mains charger I had which wasn't lithium compatible with a Victron IP67 one. My new Fogstar 100Ah lithium battery, smartshunt and various fuses and connectors are in a box ready to be installed as soon as I get a chance. I would say though, my T6.1 had the VW factory second battery but did not have that shunt device on the neg battery terminal, and didn't have anything on the 100A fuse on the battery fuse box. See pic of how I installed the DC to DC just before I cut out the SCR and transferred connections across. I'm planning to use in-line midi holders / fuses in place of what's on the battery mount fuse box. I'll post more photos of the install when I get the battery installed in the next few days.

View attachment 281500

Mind sharing a simple step by step on getting the DC-DC in, instead of the split charge?