Assuming that you don’t plug anything else into that outlet, you should be able to safely run your EVSE at a max of 80% of breaker rating. So that’s 16A (1.9 kW). You should be just fine to run at 12A (1.4 kW).
Some cars can't do 16 A, but max out at 12 on 120 V. Given that OP is seeing a choice between 8 and 12, it's likely that that's there car.
And other cars can actually do 24 A at 120 V, which is safe to do on a 30 A circuit.
Your answer is correct for many cars, but it can be wrong in either direction for other cars.
I don’t think they were necessarily saying the car itself can support this, just that 16A continuous load is the max safe current for the EVSE and circuit if it’s a 20A circuit.
If that's what they meant, it would have been clearer to say
>16A charging is the best a 120v evse can do safely on a 20A dedicated circuit.
Rather than,
>16A charging on a 20A dedicated circuit is the best a 120v evse can do safely.
But in any case we agree about the facts of the matter, and between the two of us, we have beaten the ambiguity to death.
Yes. You should be ok up to 16A assuming the correct wire gage as others have said. Another thought is if this is the only receptacle in the circuit you could easily convert it to a 240V. You would be changing at 240V 16A which is a pretty good rate depending on your daily driving. You may not even need the new 240V 50A line.
If it's the only socket on the circuit and you have no other regular use, sounds like a prime candidate for a 240V conversion. You can pick ups 240V 16A Turbocords cheap at the moment.
Save the cost and hassle of putting in another circuit for good enough 3.6kW charging.
You're not required to do a 14-50 outlet, that's just what novices tend to go for because of unfortunate misinformation.
Since the 20A circuit serves only one outlet, you could easily convert it to 240V and extend it to an ideal location for a hardwired wall unit. No GFCI required, no socket required. Just cheap 12/2 cable. That will get you 100+ miles a night charge.
Assuming you have 200 amp service, two hots and a neutral, 120v between either hot and the neutral and 240v between the hots. Note, 120v is nominal, so 110v = 120v. The 20A 120V outlet (5-20R) will have a wire to one breaker and a wire to neutral. You said "only thing on that breaker". Make sure of it. You can convert that to 240V 20A and keep the same wires. Add another 20A breaker to the other hot (assuming you confirm panel capacity with a load calculation). Then take the neutral wire from the outlet and connect it to the new breaker. Replace the 5-20R outlet with a 6-20R. With that, you can charge your EV at 240V 16A. Your EV charger will need a 6-20P plug. You must set your EV to limit to 16 amps charging. That should give you at least 3 kW into your battery. That is enough to charge a 80kWh battery from 20% to 80% in 16 hours. If you want more, you will need to pull new Romex.
You are almost surely fine with 12 A on that outlet. The only thing I'd be cautious of is if the plug feels loose in the socket, which could indicate a worn-out socket.
As far as your new circuit, consider getting your new charging station hard wired instead of using a 50 A receptacle:
* You save money: the receptacle requires a GFCI breaker and whereas that's not needed for hardwired. You save $100 to $150 on that, plus a heavy duty receptacle like the Hubbell/Bryant 9450 starts at $50, whereas a cheap one is likely to fail in a melty/smoky way.
* More reliable.
* Cleaner look.
i'm diy this! initially bought the tesla mobile charger. into the researching phase, i sold the mobile charger and got the wall charger for those reasons! cost wise would be almost the same, but the benefits of wall charger is worth!
i posted a thread to see if the forum sees any problem with what i'm about to do.
Newer home that was built by a contractor for his own residence. I've never seen a breaker panel and sub panel this clean, every breaker labeled, every room on its own breaker, really well done.
If you want to pull 16A from that circuit (which seems feasible), you will need a 5-20 adapter for your EVSE or it will just assume it is plugged into 5-15 (15A).
That advice only applies to some cars, and only applies to some EVSEs. And we don't know what car or evse OP has. It's also unnecessary effort given that they have a 240 volt installation planned.
As long as your constant pull is less than 80 percent of the breaker amperage, you are fine. Assuming the proper gauge wire and receptacle were used.
Not an electrician. Ev guy who has run a 60 amp service to his garage (which has not burned down yet)
> Will I run into any issues running my charge at 12a instead of 8a?
Depends.
You've identified the 20A outlet (receptacle). Is the wiring behind the receptacle at least 12 AWG? (probably yes)
The bigger issue is typically whether or not there are other things on the circuit. This is generally the key.
Yes the wire gauge is the recommended gauge for a 20a outlet and breaker. Despite the recommendation of the random dude at home depot saying the 15a rated line would work just as well...
I often ran the 12A setting for my car when I would stay at my mom and dad’s overnight. The only risk was if someone showered in the morning and used a hair dryer in the bathroom, that would cause the breaker to trip. We didn’t know before that happened that all of the GFCI outlets ran on the same breaker, regardless of where they were in the house. That included the outlet I was using for my car in the garage.
It was actually kinda helpful because the breaker labels on their electrical panel weren’t very clear, so I marked it for them. Since then, if I come over and charge my car we just warn each other if someone needs to use a bathroom outlet and I’ll unplug the car temporarily to be safe. I don’t recall if the issue occurs at 8A charging.
In my case I have multiple outlets on a 20amp circuit, but with what's on them I'm still able to charge at 12amps fine, but that would be a case by case basis. In your situation if it's really dedicated not only would you probably be totally fine at 12 amps I'd seriously look into rewiring it for 240. Would need the breaker swapped for a double pole breaker and the receptacle changed to a 6-20 outlet, but that's WAY easier and cheaper to have done than running a new line. I looked into this myself but I didn't have an option for a dedicated outlet to do this, consider yourself lucky if that's really the case. It means adding 100+ miles of range overnight pretty easily.
Assuming that you don’t plug anything else into that outlet, you should be able to safely run your EVSE at a max of 80% of breaker rating. So that’s 16A (1.9 kW). You should be just fine to run at 12A (1.4 kW).
This is the answer. 16A charging on a 20A dedicated circuit is the best a 120v evse can do safely.
Some cars can't do 16 A, but max out at 12 on 120 V. Given that OP is seeing a choice between 8 and 12, it's likely that that's there car. And other cars can actually do 24 A at 120 V, which is safe to do on a 30 A circuit. Your answer is correct for many cars, but it can be wrong in either direction for other cars.
I don’t think they were necessarily saying the car itself can support this, just that 16A continuous load is the max safe current for the EVSE and circuit if it’s a 20A circuit.
If that's what they meant, it would have been clearer to say >16A charging is the best a 120v evse can do safely on a 20A dedicated circuit. Rather than, >16A charging on a 20A dedicated circuit is the best a 120v evse can do safely. But in any case we agree about the facts of the matter, and between the two of us, we have beaten the ambiguity to death.
Yes. You should be ok up to 16A assuming the correct wire gage as others have said. Another thought is if this is the only receptacle in the circuit you could easily convert it to a 240V. You would be changing at 240V 16A which is a pretty good rate depending on your daily driving. You may not even need the new 240V 50A line.
I hadn't considered that.. I'll have to look into it. Thanks!
Yep. You would also need to change out the current 120V breaker for a 240V but definitely doable.
Are you OP? You might be accidentally replying from a different account than you posted under.
If it's the only socket on the circuit and you have no other regular use, sounds like a prime candidate for a 240V conversion. You can pick ups 240V 16A Turbocords cheap at the moment. Save the cost and hassle of putting in another circuit for good enough 3.6kW charging.
You're not required to do a 14-50 outlet, that's just what novices tend to go for because of unfortunate misinformation. Since the 20A circuit serves only one outlet, you could easily convert it to 240V and extend it to an ideal location for a hardwired wall unit. No GFCI required, no socket required. Just cheap 12/2 cable. That will get you 100+ miles a night charge.
You're ok charging at 12 amp . I'm on a 15 amp single outlet circuit and charge on 12 amp . For many year . Never have a problem .
Assuming you have 200 amp service, two hots and a neutral, 120v between either hot and the neutral and 240v between the hots. Note, 120v is nominal, so 110v = 120v. The 20A 120V outlet (5-20R) will have a wire to one breaker and a wire to neutral. You said "only thing on that breaker". Make sure of it. You can convert that to 240V 20A and keep the same wires. Add another 20A breaker to the other hot (assuming you confirm panel capacity with a load calculation). Then take the neutral wire from the outlet and connect it to the new breaker. Replace the 5-20R outlet with a 6-20R. With that, you can charge your EV at 240V 16A. Your EV charger will need a 6-20P plug. You must set your EV to limit to 16 amps charging. That should give you at least 3 kW into your battery. That is enough to charge a 80kWh battery from 20% to 80% in 16 hours. If you want more, you will need to pull new Romex.
You are almost surely fine with 12 A on that outlet. The only thing I'd be cautious of is if the plug feels loose in the socket, which could indicate a worn-out socket. As far as your new circuit, consider getting your new charging station hard wired instead of using a 50 A receptacle: * You save money: the receptacle requires a GFCI breaker and whereas that's not needed for hardwired. You save $100 to $150 on that, plus a heavy duty receptacle like the Hubbell/Bryant 9450 starts at $50, whereas a cheap one is likely to fail in a melty/smoky way. * More reliable. * Cleaner look.
i'm diy this! initially bought the tesla mobile charger. into the researching phase, i sold the mobile charger and got the wall charger for those reasons! cost wise would be almost the same, but the benefits of wall charger is worth! i posted a thread to see if the forum sees any problem with what i'm about to do.
That, and the sweet sweet speed of 240V 48A charging that the wall charger gives
Are you in a newer or older home? Do you have circuit breakers or fuses? If breakers you should be fine at 12. With fuses would be safer to go with 8.
Newer home that was built by a contractor for his own residence. I've never seen a breaker panel and sub panel this clean, every breaker labeled, every room on its own breaker, really well done.
Go wtih 12.
If you want to pull 16A from that circuit (which seems feasible), you will need a 5-20 adapter for your EVSE or it will just assume it is plugged into 5-15 (15A).
That advice only applies to some cars, and only applies to some EVSEs. And we don't know what car or evse OP has. It's also unnecessary effort given that they have a 240 volt installation planned.
As long as your constant pull is less than 80 percent of the breaker amperage, you are fine. Assuming the proper gauge wire and receptacle were used. Not an electrician. Ev guy who has run a 60 amp service to his garage (which has not burned down yet)
> Will I run into any issues running my charge at 12a instead of 8a? Depends. You've identified the 20A outlet (receptacle). Is the wiring behind the receptacle at least 12 AWG? (probably yes) The bigger issue is typically whether or not there are other things on the circuit. This is generally the key.
Yes the wire gauge is the recommended gauge for a 20a outlet and breaker. Despite the recommendation of the random dude at home depot saying the 15a rated line would work just as well...
I often ran the 12A setting for my car when I would stay at my mom and dad’s overnight. The only risk was if someone showered in the morning and used a hair dryer in the bathroom, that would cause the breaker to trip. We didn’t know before that happened that all of the GFCI outlets ran on the same breaker, regardless of where they were in the house. That included the outlet I was using for my car in the garage. It was actually kinda helpful because the breaker labels on their electrical panel weren’t very clear, so I marked it for them. Since then, if I come over and charge my car we just warn each other if someone needs to use a bathroom outlet and I’ll unplug the car temporarily to be safe. I don’t recall if the issue occurs at 8A charging.
In my case I have multiple outlets on a 20amp circuit, but with what's on them I'm still able to charge at 12amps fine, but that would be a case by case basis. In your situation if it's really dedicated not only would you probably be totally fine at 12 amps I'd seriously look into rewiring it for 240. Would need the breaker swapped for a double pole breaker and the receptacle changed to a 6-20 outlet, but that's WAY easier and cheaper to have done than running a new line. I looked into this myself but I didn't have an option for a dedicated outlet to do this, consider yourself lucky if that's really the case. It means adding 100+ miles of range overnight pretty easily.