Hi folks, just trying to understand what I saw here
https://www.victronenergy.com/live/ac_coupling:start
That minimum battery would be 4.8kWh of 48v LiFePO4 battery per 1.5kWp PV?
so for 20x435w panels = 8.7kWp
that's (8.7/1.5)x4.8 = 27.8 kWh
So need 6 x 4.8kWh pylon us5000?
I would like my system to run from solar and/or battery during a power cut.
Thinking of RS450/200 with Multiplus 10k,
I have single phase utility supply
I think you may be confusing ac with dc coupling. Your link is for an ac inverter, yet your preference is a 450/200 charger. Both have their pros & cons, and can even be mixed. Depends on your setup as a whole, and maybe even your overall aims.
There's a little here about sizing Pylons (not your model, but should convert ok with capacity).. https://www.victronenergy.com/live/battery_compatibility:pylontech_phantom
This won't accurately match your link, but it isn't really considering the frequency-fiddling/buffering needs of full ac.
There's lots of reading available on the Victron website. This one is indicative of the different ways you might configure kit.. https://www.victronenergy.com/upload/documents/Booklet-Off-Grid-System-EN.pdf
Have fun choosing. But don't spend before you're absolutely sure.
Thanks for the links @JohnC, will take a look.
Because of potential build having 10 panels East, 10 panels West and a possible future expansion to add 9 on a south wall I had been thinking of using the 450/200 to provide MPPT capability for panels with ~40V Voc. I'm trying to get my mind around the victron way of doing things and how the many different component choices make sense and stand a chance of at least half-understanding any quotes I receive!
As @JohnC says, some of the constraints do not apply if you are connecting the panels on the DC side bc the inverter can throttle the power produced by the MPPT. E.g. I have got 6.9 kW of panels, split between an AC inverter on AC-Out and a DC MPPT and this does not violate the 1:1 rule.
Also some of the proportions are intended for mainly off-grid installations. A good way of sizing batteries for a grid connected system (with coverage of occasional power cuts) is to allow for a min of 2 hrs duration at max nominal inverter output. So I have got 10.65 kWh of Pylons on a Multi 5k which is enough for a medium-sized house.
