No, it is not free, but most reviews say it can be up to 50% cheaper than public charging stations. It all depends on what you are being charged per KwH at home versus what the charging station charges you per KwH. You hunt around to get the best price you can at home from a supplier on contract, but are at the mercy of what a charging station wants to charge,
The formula to work it out at a basic level is: EV Battery Size (kWh) x Electricity Rate ($ per kWh) = Charging Cost ($).
So a 60kWh battery and an electricity rate of $0.50 per kWh, you would be looking at charging your EV at a total cost of $35.75.
Your costs are also reduced if you have rooftop solar installed and if you charge your EV when rates are low, through the early hours of the morning, for example.
One thing they don't mention is that it costs $1000 - $2000 to get a charging station installed at your home. Then there is the higher cost of the car and replacement battery (every ten years - necessary to even sell it then), the cost of getting the replacement battery installed after 8-10 (say $1500) and a state tax per km to replace the fuel excise. Other issues include a drop of up to 30% in battery efficiency over 8 years, the fact that you should not let the battery drop below 15% before recharging. Probably still cheaper than hydrocarbons, but not so much as they claim, and dependent on your km driven per year (your battery is still dying over time regardless of km driven). And art the moment not so great for regular long trips.
This is why I say I want to see an accurate TOTAL cost - dealers, greens and governments are pushing them without giving overall costs. Which is why I am holding off as long as practicable before deciding to replace our little runabout.