Just a couple of questions 

both Victron and Pylon need to be kept indoors and have you thought where?

for your FIT system you need an AC inverter to your battery for it to all operate together but your garage system could be a hybrid (and hence more efficient). Have you considered that? And to be most effective they should be managed together with an appropriate app, do your chosen products have that?

There’s no SEG anymore so it just on your electricity supplier’s term on ROI , usually good on solar. A house can have anything you want as long as you don’t touch the FIT system monitoring aspects.

just more to consider I’m afraid!

In my rush to TRY and make me first post NOT TOO LONG (failed miserably)

I forgot to mention two batteries that could be possibilities and that i am/was considering using.

The Fogstar rack mounted batteries look like a cheaper (about 30% cheaper) and are a UK supplier and look much the same as the Pylontech offering

QUESTION I think the Pylontech batteries US5000 have only 15 cells not 16?

I would have thought that this could possibly result in the batteries being overcharged, though I understand that the VE equipment works well with Pylontech batteries whereas the Fogstar rack mounted batteries have 16 cells so in my world they are spot on for a 48V battery, in the marine world I use four cells per 12V battery

Also the DIY Seplos Mason 280 kit also looks interesting {though I was looking for a recognised plug and play solution, NOT building another battery system}

Posted by: @judith

↑

Just a couple of questions 

both Victron and Pylon need to be kept indoors and have you thought where?

for your FIT system you need an AC inverter to your battery for it to all operate together but your garage system could be a hybrid (and hence more efficient). Have you considered that? And to be most effective they should be managed together with an appropriate app, do your chosen products have that?

There’s no SEG anymore so it just on your electricity supplier’s term on ROI , usually good on solar. A house can have anything you want as long as you don’t touch the FIT system monitoring aspects.

just more to consider I’m afraid!

This house has a full height cellar, so no issues with finding a good location for the new kit

Also is a Chalet Bungalow and the Solar Edge inverter is simply installed in the corner one of the rooms (loft Space) 

The SE FIT Inverter might get relocated so that all the solar kit is in the one location BUT that could mean running DC cable in the house (from the roof to the cellar) (external high strength plastic conduit is always an option here) which i think is not something that is highly recommended 

A VE Multiplus II will do the job and can take a solar input at a later date (maybe some nice panels {say ten 8.33 430 panels} on a ground mount attached to the house {instant CarPort}) (then it would be easy to include the SE FIT DC cable in this external cable run) so that it will not only be the FIT installation and the Grid that is being used to charge the batteries

This inverter could even be connected to the proposed garage roof solar in the future. And they are easy to add capacity by running two or more in parallel, they just have to be I think, the same model of identically rated inverters.

GOTASOREHEADNOW 🙁

I'm not well-enough informed on Victron products. But I realise that they are high-spec and relatively expensive.
The Aussie equivalent would be Batrium.

I don't see why you have qualms about running DC cables inside the house.
I have 24v feeds from my plant-room to distribution points on each floor, and to the workshops.
That runs 80% of the house lighting, the server-rack, internet router and hubs, telephone, security cameras etc.
I can provide further information on connections and circuit safety if you wish.

1: The cheapest approach to in-home battery storage is to use hybrid inverters, as suggested by @judith above.
The batteries themselves would be built from LiFePO4 cells, either on DIY shelving or in Seplos/Fogstar enclosures.

That approach is sufficiently cheap that it will almost certainly override thoughts of FIT income.

2: The next cheapest option is to buy in rack-mounted batteries with a BMS and fuse already within each box.
Pylontech and Fogstar both have options.
Storage capacity in each enclosure is limited by the weight you can lift under Health & Safety legislation. A 4kWh box typically weighs around 25Kg.

I use the first option. Some of the stored energy is converted up to 240v 50Hz, but off-grid.
That's not synchronised to the 50Hz of the grid, and therefore continues to operate during an outage.

If you don't export back to the grid, then you can install as many solar-panels, inverters and batteries as you like.
You don't need G99 consent from Scottish Power.
Your equipment doesn't require an MCS-approved contractor.
Connections below 75v are deemed SELV and don't require a qualified electrician.

You do still require approval from SWMBO

You are currently constrained by

• your desire to maintain income from the FIT
• the SolarEdge optimisers, which link to the matching Solar-Edge inverter