I concur, go with this. If you do ever decide to get a second EV, that's when you'd spring for the service upgrade. Your goal should be to get a full charge overnight. From my experience 1.2 kW (120 V 10 A) took more than 12 hours, but 4.8 kW (240 V at 20 A) will be plenty for overnight charging.
For me, all the fancy Amp, Volt, and Kw talk boils down to MRpH (miles range per hour) added to your particular vehicle(s), how many miles you average daily, and how long is available to charge each night.
In Jessie, I drive 65-75 miles, 5 days a week. I am home for about 12 hours on those days, but some are more and some are less (when I'm coaching night soccer games, for instance). 20A/120V adds about 5 MRpH (in either our MINI or Tesla), so even on the long nights, I'd not quite make it to full on average (5×12=60 miles added), and on mornings after games, I'd be way short; so no go. But 20A/240V adds about 15 MRpH, so that is 180 miles per night: GTG.
My wife, in her TM3, only drives maybe 20 miles a day. She could get by, easily, with 20A/120V, or share just a 20A/240V with me.
Naturally, I massively overbuilt. We have two(!) Tesla wall chargers that intelligently share a 60A/240V breaker. That means, when charging alone, either of our car's internal chargers is maxed out, 32A and about 30 MRpH on Jessie, and 48A and about 44 MRpH on the Tesla. Even charging simultaneously, the two cars will go from 20% to their stop points (full in Jessie and 80% in the Tesla) in about six hours.
I did this for a few reasons. In no particular order:
- My wife and I didn't want to have to share a connector. When either of us wants to charge, we plug into our own nozzle. And, they are each physically located in the garage precisely where we don't have to drag cables around or coil them after use; indeed, our cables never even touch the deck.
- I didn't want to worry about simultaneously drawing power and tripping a breaker. No matter what we do, it is impossible for us to draw more than the 48 Amps our connectors are set to share.
- If one of the connectors fails, we have a spare.
- We can host EV guests easily.
- Because of the quick charges, I can take full advantage of the night time electricity rate. I pay about $0.08 per kWh (all hail Texas!) out the door between 0000 and 0600, so setting my timers on both cars to begin at midnight means they are all done inside the window.
- Although the case I presented for 20A/240V is completely doable, it is on the thin side of doable; it requires a bit of foresight and doesn't allow for deviations very well. Having a couple of flamethrowers in my garage means, say, if I forget to plug in one night, catching my mistake at 0630, will give me an hour on the charger at 30 MRpH, enough charge to get to work and home again (including the 40 to 50% already in the tank).
- Having full charging power available is occasionally nice for a weekend Tesla road trip top off. We arrive home after work on Friday, and while we pack and get ready, the Tesla will charge from 75% to 95% or more, before we push out for the trip.
- Similarly, returning from a road trip in the Tesla on a Sunday night at 5% garners no worry for my wife, if we have 48A available to charge her car to full by the morning.
