In this reference design and this other design the positive from the MultiPlus/charger and the positive of the MPPT solar charger are not permanently connected - they are separated by the Cyrix Li Charge. Is the Cyrix necessary to separate these parts, or could they be permanently connected?
From the docs
The Cyrix-Li-Charge will connect a battery charger with 3 seconds delay:
- if the Charge Disconnect output of the VE.Bus BMS is high, and
- if it senses 13,7V (resp. 27,4V or 54,8V) or more on its battery charger connection terminal, and
- if it senses 2V or more on its battery terminal (the Cyrix will remain open, if not connect to the battery)
#1 requires an input from VE.Bus, which AFAIK is incompatible with non-Victron batteries (which I hope to use). So if the Li-Charge is not necessary, I would remove it. Is it necessary? What goal does it achieve? And why would it be a good idea to disconnect the MPPT and Orion, but not disconnect the MultiPlus?
If the Cyrix is necessary then I could drive it from a relay using some other logic, though my goal would be to allow the generator to charge the batteries (via the MultiPlus) at the same time that the PV/solar charges the batteries.
This design does that, but makes no reference to a generator, but presumably the MultiPlus would accept that AC input.
I see there are other designs that permanently connect a Smart Charger to an MPPT (not MultiPlus).
Tangential question: Are the 'Main Switches' (1, 2, 3) in these designs intended to be isolation switches (to be placed in open position for servicing, repair, storage, etc)? Or do they exist to allow the user to 'change modes' of their system? E.g. from one charging source to the other? (and by extension may require such user interaction). I assume the former, but would be good to get confirmation.
Thanks!
