Charging Question at 120v

It may take up to 8 hours to charge at 8 amps. I wouldn't install a 20 amp receptacle. I'd use whatever is available including running an extension cord. If I were to install something, I would install something more future proof for a full on BEV as recommended above.

At the very least do nothing at all until you get the cars. Given that you live in CA, you may find an additional ~15 kWh of daily usage will push your electricity cost to an expensive tier. You may decide to go solar requiring a completely different electrical box or decide not to charge at all as gasoline costs less. You not like the cars. You may move. You may decide to do the EVSE upgrade and use a dryer outlet for L2 charging.

My sister has a Leaf and a Volt. She charges from the regular 120v outlet and takes turns. The Leaf gets priority obviously. Just consider that there may be no need to upgrade anything.

 

A 15 amp cord is cutting it a little close. I'm more comfortable with 10 gauge for the extension cord. They do get pricey at that size, though. Maybe you can borrow one and see if it gets warm?

 

It's interesting that the #12 and the #10 both say 15 amps. Must be a difference in either insulation or plug. If it was me, I'd be more comfortable with #10, though, especially at 15 feet. Mine is only 10 feet long and stays nice and cool. Sometimes I wish I'd gotten a 25 footer and may still give that a try. My EVSE won't reach the only outdoor outlet at church. There's just one spot where I can reach with the 10 foot extension.

 

Sorry, I was assuming you'd use a dual outlet. It would be a violation with a single outlet.

 

I don't think that matters. What matters is whether or not the smaller outlet has a pass-through current rating that can handle the circuit breaker trip rating. Trouble arises when an outlet starts overheating and melting at a current too small to trip the breaker.

15A and 20A parts seem to be a special case, with certain degrees of interchangeability that generally don't generically apply to components at higher currents.

Some webpages I found pointed to a specific NEC section that would be violated by the preceding proposal. I don't have a full copy to verify, only the portions relevant to my DIY home PV installation.

 

Phil, switch off those breakers that you think connect to nothing. Live with that for a few days and see if anything isn't running that ought to be. If indeed those are unused breakers, then your source problem is solved. Two new 20 amp circuits to the garage can come from those unused breakers.

That paired 20 amp is supplying 240 volts to something--or nothing. What appliances or heaters do you have that require 240 volts? Something you're just not using today, or something removed long ago?

It is always good to label the breakers...furnace, refrigerator, living room lights, spare, etc.

 

In fact, it is a requirement under modern electric codes.

Upgrade -- put your own labels on, next to the breakers!

 

Correctimundo! The breaker is there to protect the wires and the outlet, not necessarily the device plugged into it. If you plug a 28 amp load into a 15 amp receptacle on a 30 amp breaker, the receptacle will melt and possibly ignite regardless of if it's a solo or tandem outlet.

 

I am not an electrician. I am an idiot on the internet. Don't listen to what I say.

My owners manual for a PiP says Toyota doesn't recommend using an extension cord period. On Priuschat here, most say use minimum 12 gauge. 10 would be safer. The EVSE has a button that tests the outlet to see if you can use it. I use that button.

I've read a couple of horror stories here where the circuit is shared or there is shoddy electric lines. For me, I considered it using a space heater. I try to make sure nothing else is plugged into the same circuit. If something trips the breaker I reset it and find the culprit and remove it. I lived in a home built in the 60's. I already know the outlets in the kitchen are not up to code. So just like a space heater I proceeded cautiously. I plugged in only while I was awake the first few days just so I don't get caught off guard. I found out out the living room outlet where the television was plugged in shared the garage outlet. That was enough to trip the breaker. After doing some switching around, I was good.

 

What is an *extension cord?* To some people it is a length of skinny zip cord with a 2-prong plug and connector dangling from too-long stripped ends and a wrap of tape around the bare spot the puppy chewed. To other people it is an industrial heavy duty #12 or #10 portable cable with molded 3-prong ends.

The charger only pulls 12 amps. A #14 3-wire cord is adequate. A #12 is better. That's what I use. A #10 is overkill, but nothing wrong with that. Don't buy one longer than necessary.

Upgrading the receptacle to a $2.79 commercial duty receptacle is a good idea, better than the 59¢ version most of us have in our houses.