Best option with only 120v outlet (for now)?

[bluedevl]

I really appreciate all the information and guidance I've gotten from this forum since beginning my i3 research. My new guy (2014 Laurel Gray REx w/Tera) was a good deal so I jumped on it. He's in the process of being shipped to me so it's time to work out the details

My underground parking garage with deeded parking isn't ideal for installing a L2 EVSE and the potential expense/HOA hassle involved is still being evaluated. There are, however, multiple 120v outlets that I can use until that is sorted. I also have a few convenient locations near my building to charge quickly so I'll definitely be able to make do for a while.

What I'm wondering is if any of the EVSE cables that claim to provide higher-speed charging (L1.5, etc.) from a 120v outlet are safe and if others had any experience using them. Since charging at work may be an option, I may be tempted to use a reasonable 120v solution at home for a while if I can find something that will give me a reasonable overnight charge.

 

[jadnashuanh]

120vac receptacles generally are on either 15A or 20A circuits (and you CAN use a 15A receptacle on a 20A circuit, but not the other way around - you might have 20A available, but to get it might have to swap the receptacle to a suitable one). USA electrical code requires a device that can run more than 3-hours (I think that's the number...IOW, not a short duration thing like a toaster) to only use 80% of the maximum load. So, on a 15A circuit, you can only use 12A, and on a 20A circuit, that would equate to 16A. A device would need a 20A receptacle to utilize that 16A, which has a different plug...one of the leads is 90-degrees to the other. If you look at a 20A receptacle, one of the slots will be a T-shape...that indicates it is a 20A device. Either 'normal' plugs with parallel prongs or a 20A plug will fit into it.

So, it really depends on what's available to you. The EVSE that comes with the i3 in North America is rated at 12A so that it can fit into any 120vac receptacle. If you bought one rated at 16A, it would only plug into a 20A receptacle if it were to meet the electrical code.

Note, sometimes when they run 120vac circuits, they'll run a 3-wire cable that can support two separate 120vac branches that share a neutral. IF that's the case, it's easy to swap the plug and rewire things for 240vac. Since power=volts*amps, doubling the voltage means doubling the power. Because of the phasing, the neutral cannot be overloaded on this type of circuit because it can never be more than one branch at it's max. Any current on the other branch cancels the current in the neutral. The most common cable would then have white/black/red and safety ground...you'd only use the black and red and safety ground to get 240vac. So, you might be able to get 240vac where there's a 120vac receptacle. This requires the double circuit breaker to be ganged...i.e., if one branch trips, it opens the other side as well.

FWIW, the EVSE levels (1 or 2) indicate the input voltage level, not their maximum charging rate. While it's true a level 2 unit GENERALLY will support higher current, that is not a certainty. It depends on how it was designed. There are some aftermarket EVSE's that can operate at either 120 or 240vac.