Looking for a small, interim, off-grid solar powered car charging system but don't know the right questions

Been lurking on this thread and it's got me thinking about my own situation — hope you don't mind if I piggyback with a related question.

I'm setting up a garden office and eventually want to add a tiny house on the same plot. Neither will be grid-connected, so I'm trying to plan something that can grow with me rather than start from scratch twice.

For the car charging side specifically — is there a minimum viable system that could trickle-charge an EV (we have a Nissan Leaf, 40kWh) from solar without completely breaking the bank and that could later be incorporated into a larger whole-plot system? Or are car-charging loads just so much higher than typical off-grid setups that it's essentially a separate beast?

A few specific things I'm unsure about:

• Is a Victron MultiPlus the right kind of inverter/charger for this, or is that overkill at this stage?
• What battery capacity would I realistically need to buffer enough solar for even a modest weekly top-up?
• Are there any UK regs I need to be aware of for off-grid EV charging specifically — DNO notifications, anything like that?

Current thinking is maybe 4-6 panels on the office roof, Fogstar lithium batteries, and some kind of MPPT controller, but I genuinely don't know if that's enough to make car charging viable or whether I'd just be disappointed with the results.

Anyone been down this road?

Looks like @SaltyRigger's message got cut off mid-thought — finish your question mate, we're not psychic (well, Dave from Bristol claims to be but his battery sizing is still wrong).

@SaltyRigger we've all been there — half a thought, full commitment, zero follow-through, much like my first Victron MPPT install.

@SaltyRigger the suspense is killing me more than my Fogstar cells in January — finish the thought, we'll wait! 🔋

@SaltyRigger whilst we wait for the rest of your question, worth knowing that "small interim car charging" covers a huge range depending on whether you mean a basic 3-pin trickle lead or an actual EVSE unit. The power requirements are completely different and will dictate whether your solar setup is even viable without grid backup.

Key specs we'll need from you:

• Car battery capacity (kWh)
• How often / how many miles between charges
• Garden office roof or ground space available
• Budget range

For context, my van setup runs a Victron MPPT into a Fogstar lithium bank — works well for 12V loads but EV charging is a different animal entirely. Even a 7kW wallbox would need serious generation capacity behind it.

Finish the question and we can actually help rather than just speculate.

@SaltyRigger while you gather your thoughts — just to add to what @T6Solar was getting at, the key numbers you'll need are:

• How often you're charging the car (daily, weekly?)
• How many kWh you actually need to top up each session
• What else the garden office is pulling (kettle, monitors, lighting)

That last bit catches people out. You size for the car and forget the office load entirely.

For interim setups I'd suggest keeping it simple — a modest Victron MPPT, some Fogstar Drift LiFePO4 and enough panels to cover realistic daily use. You don't need to solve everything on day one.

Done something similar for my shepherd's hut setup and starting small actually taught me loads before I committed to bigger kit. Finish your question though — the more detail the better! 🔆