240 Volt charge what amperage to install?

The wiring, circuit breaker and outlet are all likely to be less expensive on a 20 amp circuit. I charge my prime off a 20 amp 220v circuit. The charger that is built into the car determines how many amps it draws from the house.

You won't need a higher amp rating unless you drive a lot every day. A 16 amp at 220V charger will replace the energy needed to drive 14 miles each hour that it ins charging. That's roughly true for the Tesla too. It's easy to get into the "bigger is better" when charging EVs but the reality is that you will do fine as long as the nightly charge replaces the energy that you use each day.

In my case, I seldom drive more than 25 miles in a day. because of that, all of the currently available BEVs and PHEVs, all of them would finish recharging overnight on my 20 amp circuit.

Dan

 

Regardless of the current capacity of the line you plug into, the equipment will only draw what it NEEDS.
That is assuming that the voltage is right for the device.
You could install a 1000 Amp circuit and it still would be fine.

 

All of these folks are giving you good advice, I have one further piece of advice, which might be good.

Lets dream that you want a 14-50 outlet, it is very common and about as much 240v power before you need to hardwire the EVSE in, rather than use a plug. if you have a 50 amp plug, it should be backed by 50 amp wiring, for safety.

But while you 'just' have a Prius Prime, the 20 Amp breaker is safest. any unusual draw will protect the car and the house.

Then, in the future, when you want more Amps, you only have to upgrade the breaker as the circuit is 50 Amp ready. (40 amp if you new car draws 32 Amps) A 50 Amp breaker will safely power a 40 Amp EVSE.

Sample 40 Amp EVSE, which will not be any faster than a 16 Amp EVSE on a Prius Prime. Lectron 40 Amp Electric Vehicle (EV) Level 2 Charger 240V NEMA 14-50

Sample 16 Amp EVSE with a 14-50 plug http://www.amazon.com/Megear-Charger-Portable-Electric-Charging/dp/B08BCGSQQS

 

40-amp line (which supplies 32 amps sustained) will provide roughly 200 miles of EV range in 8 hours.

That rule-of-thumb gives you a general idea of where some type of mainstream expectation will settle. It's the "7.2 kW" rate often sighted. The next larger gauge wire (6 instead of 8) will support a 50-amp line, the maximum for NEMA 14-50 outlets. That would bump rate up to 10 kW. There wouldn't be any benefit if your future vehicle isn't designed for faster though. The rate itself can be even higher, but to support that the EVSE (charging unit) must be hardwired rather than using an outlet.