By Dave Miller · off-grid sparky · 22 years wiring solar, batteries and sheds in central QLD
“After frying my inverter trying to charge an EV on a cloudy winter morning, I learned off-grid needs double the battery bank I originally planned.”
— Dave. Measure twice, buy once.
ArticlesCalculatorsSite PlannerShopLook, if you're dreaming of charging your EV off-grid in the Outback, forget the hype. It's possible but not for everyone. Here's the blunt truth.
Look, if you're dreaming of charging your EV off-grid in the Outback, forget the hype. It's possible but not for everyone. Here's the blunt truth.
Forget the "5kW solar" sales pitch. Off-grid EV charging needs serious numbers. Your daily EV energy use is 20-30kWh (for a 400km range). Solar must cover that AND your house.
Rule of thumb: 1kWh of EV charge = 3kW of solar panels (due to inefficiencies, weather, battery losses). For a 25kWh daily EV use: minimum 75kW solar array. That's 20-30 panels. Not a backyard setup.
Real talk: Most off-grid homes run 2-3kW solar. You'll be charging your EV at 10% capacity on sunny days. Or you'll need a generator backup. No sugarcoating.
Chademo (Japanese) and CCS (European) are the only fast-charging options. But in Australia, CCS is king. Chademo is dead in the water here.
Why? Chademo chargers are obsolete. Only 30 exist in Australia (mostly in cities). CCS is standard on all new EVs (Tesla Superchargers use CCS, plus Hyundai, Kia, BMW, VW). Buy a CCS charger. End of story.
Australian Supplier: Solar Hub sells CCS chargers. 11kW unit: $3,200 + $1,800 for installation. Total $5k. Chademo? Not worth the effort.
Charging an EV off-grid drains your battery bank like a 1000W kettle on full blast. Lithium batteries (like Tesla Powerwall or Victron) handle it better than lead-acid, but they'll still take a beating.
Example: 25kWh EV charge = 30-40% of a 100kWh battery bank. If you have a 50kWh system, you're using 50-80% of your capacity just to charge the car. Your house runs on fumes after that.
Don't expect to run your fridge, lights, and EV off the same battery. You'll need a second battery bank just for the car. That's $8k-$12k extra.
Step 1: Check your current off-grid system. If it's under 5kW solar or 20kWh battery, forget EV charging. You'll be stuck with a $20k charger and no power.
Step 2: Calculate your actual EV use. Not the manufacturer's claim. Drive it for a month. If you do 100km/day, you need 10kWh/day. That's 30kW solar minimum.
Step 3: Get a quote from a solar installer who does off-grid. Solaris charges $500 for a feasibility study. Worth every cent.
Solar Arrays: 75kW system (for EV charging): $75k-$90k (including panels, inverter, mounting). $75k is the absolute minimum for a 25kWh EV use.
CCS Charger: Solar Hub 11kW: $3,200 + $1,800 install. Victron 22kW: $5,500 + $2,500 install.
Battery Bank: 50kWh lithium (e.g., Tesla Powerwall 3): $15,000. Add another 50kWh for the EV: $15k. Total battery cost: $30k.
Real Cost Summary: $75k solar + $5k charger + $30k batteries = $110k minimum. This isn't "off-grid EV charging" – it's a small solar farm with a car.
Worth a watch: 50 kWh Anker Battery + 56 Solar Panels! My Home Setup Charges My House & EV For Free · The Electric Viking
While many off-grid projects are achievable as DIY, certain situations require licensed professionals:
Always check local regulations and obtain necessary permits before commencing work.