I can see the day when there are two batteries, one can be taken...

I can see the day when there are two batteries, one can be taken from an Electric Vehicle and swapped to be charged at home.

The second battery can be already charged and be placed in the car, (similar to a mobile phone).

Then that charged battery, (at home) could go onto and act as a power storage for the house if required, as well as replace the depleted battery in the car.

So, both batteries could be charged and power both the car and/or the house when required.

So, also at the end of the batteries life cycle, the batteries could be sent for recycling and replaced with new batteries and/or recycled batteries, saving costs on not having to replace the whole car.