I have been researching options for providing power to a detached building, but there are a few things I'm unclear about, and would like some suggestions from those who might have more experience with the products Victron offers.
I am in NA and will need 120-0-120V split phase. I plan to use solar as my primary source, with a large battery bank -- looking at the LiFePo4 Smart 12V 330AH cells in a 48V series configuration, likely a couple strings in parallel.
At the moment, I have a single 15A 120V run to the building, which COULD be upgraded to 240V (using the two phases from the main building panel), but it wouldn't be trivial. I would like to have the option of using either 120/240V, and would rather use it as sparingly as possible -- perhaps something like a configurable (5A?) current limit to avoid consuming grid power all night to cover the load AND fully charge the batteries, and leaving solar energy on the table all day. (Obviously this will cycle the batteries more, and may be a compromise I decide to tune over time.)
I have looked at the MultiPlus, Quattro, and Phoenix inverter/charger units, which have PowerAssist, and that seems like it does more or less what I want... except it appears to be designed to "boost" the input AC via the batteries, vs. acting as a current-limited charger paired with an always-on inverter, which is more what I'm aiming for. I don't know if the difference is significant, re: duty cycles and so on, and there seems to be more emphasis on the "transfer switch" capability, whereas inverter + charger wouldn't use a physical disconnect at the AC input at all. It seems like my strategy might be more of an abuse of this feature than an intended use.
While I'm on the topic of topology, my personal philosophy has always been to prefer a modular system, both for growth flexibility and to avoid "all eggs in one basket" in case of unit failure. I had planned to start with one inverter (or two, as necessary for split-phase, preferably without an external transformer), and perhaps add additional units for fault-tolerance and load sharing. If I select one of the bespoke inverters (no charger, no grid connection) I could then add separate MPPT and grid charge controllers on the DC side. This strikes me as a fine solution, but it seems the all-in-one units are far more sophisticated, and I'm not sure the separate boxes would have the connectivity with each other and compatible controller solution(s) to maintain the battery SoC, load/charger disconnect, and monitoring. Or at least not as effectively.
Which brings me to my next quandary. VE.bus, VE.Can, VE.Net, VE.Direct... I feel like I need a matrix of what can talk to what, and which interfaces allow for what integration features. It seems like maybe VE.bus is required for paralleling inverters, but I'm honestly not sure, and not even totally positive that some of these aren't the same thing.
A little nudge in the right direction would be appreciated.
