Charging Solutions for 120V service

[Pilot1226]

Hi all,

I've posted this months ago on Reddit and other EV related forums, but now that I am getting more serious about ordering a Model Y, I need to figure out if I can run with this...

I am considering the LR AWD Model Y with the basic 19" Gemini wheels when my lease ends on my current ICE car. That will happen sometime around now (summer) next year, but could be sooner depending on lease buyback/trade-in offers. At the very latest, it will be returned December of 2021. Other options I might add include the trailer hitch for a bike rack, and possibly changing to Black or MSM paint.

I drive around 20 miles for work (round trip), which is a mix of city and highway. I am expecting, pessimistically, around a 300 Wh Mile, and hoping to be surprised closer to a 250 Wh Mile. I have two kids that are involved in town sports, which usually adds less than 5-10 miles to the day's total a few (2 or 3) nights per week.

During the summer, I'll find myself driving to the shore areas around once a week, occasionally commuting from there, which is about 60 miles each way. There are lots of Supercharging options both near work and on the way between that are convenient enough that I won't be annoyed if I had to stop there for a few minutes. I'll also have destination charging (120V15A outlet) available at all points if I'm in a pinch.

My house is nearly 100 years old, and while the electrical panels and wiring have been upgraded over the years, it would require another panel replacement to allow 240V charging - which I've checked with 3 different electricians. The panel install estimate is somewhere in the mid to high teens ($1500 was low, $1800 was highest) but did also include a 14-50 circuit run of about 30 feet plus the outlet. I would probably consider going for the HWC if I went this route, which would then add an additional $500.

I'm looking at either having a 120V20A 5-20 or a 120V30A TT-30 circuit & outlet installed. The cost is expected to be somewhere around $300 to do so. In my garage, I have a 120V15A outlet (5-15) that I'd plan to just use in the interim. I'd probably have to figure out a way to use a halved PVC pipe to protect the wire from the garage door, or I'd have to figure out a way to drill a hole large enough for the cord to extend through with some type of escutcheon plate to stop critters from having easy access.

I work shift work, which has the benefit of it literally being an 8 hour work day. I will have the means to charge at minimum 12 hours between commutes. I park in a 2x2 (4 car) driveway, we do not have a large enough garage for anything bigger than a motorcycle due to home layout.

Also, I don't have "time of use" pricing from my utility. We've got tiers of pricing based on how much you use, divided into supply and delivery components. I pay roughly 17 cents per kWh, and with increased use it does jump to about 18 cents per kWh with rounding.

Thoughts:
*I am assuming 20% efficiency loss for the 120V circuits, though my understanding is that this overhead is fixed and decreases with an increase amperage, and again, I am "pessimistically" assuming a 300 Wh mile.

1. 120V15A Outlet in Garage - 120V*12A = 1440 W * .80 = 1.152 kW = 3.84 miles range per hour

• benefits: already installed, no extra cost here, adapter comes with car.
• negatives: have to figure out a way to get the cord from garage out of garage.
• slow charging - gains of 46 miles per day with 12 hours charging.

2. 120V20A Outlet near garage - 120V*16A = 1920 W * .80 = 1.536 kW = 5.12 mrph

• benefits: significantly faster charging, would be easier to access since installed outside
• negatives: installation cost, adapter needed for purchase
• better charging - gains of 61 miles per day with 12 hours charging

3. 120V30A Outlet near garage - 120V*24A = 2880 W * .80 = 2.304 kW = 7.68 mrph

• benefits: fastest 120V charging I can get, no electrical panel upgrade needed
• negatives: third party EVSE adapter needed, installation costs.
• better charging - around 90 miles per day with 12 hours charging

So, I'm a little torn here. Part of me wants to just run off of the standard 5-15 outlet, and if for some reason the garage plug gets frustrating, I could either hire an electrician to run an exterior outlet or I could try to do it myself and expand the existing outlet. I only drive 25 miles per day around 5 days a week, so over the course of a whole week:

25 * 5 = 125 miles driven weekly; charging 12 hours @ 120V*12A for 7 days would replenish 322 miles of range.

What's the best way to weatherproof the adapter itself? I am expecting a Taymac plastic box for the outlet itself if installed outside, but what solutions can I use for an enclosure for the MC? Ideally I'd like to have some type of plastic or wooden "box" that's waterproof and mounted to the side of the house for the MC to stay in and be sheltered, and large enough I could hang the cord underneath it as well.

I have an electrify america station nearby that has a Chademo, but I'd need to buy the adapter. I also could use Superchargers as needed, as well...

Thanks, all.

 

[gfunkdave]

I think you're waaay overthinking this. If you live in a place with cold winters you should probably get some kind of 240V outlet installed because the battery heaters take about as much power as a 5-15 outlet (120V, 15A) can provide. If not, you should be fine with standard 15A charging especially if you're happy visiting Superchargers from time to time.

If the outlet is not the only thing on the circuit being used, then you should probably get a new circuit of some kind installed. That is, if the garage outlet shares a circuit with the outlets in the kitchen or living room or something, you'll probably want a new circuit. If it's just shared with the garage door opener then that's fine since the opener doesn't run for more than a few seconds at a time.

If the $1500 to put in a new panel and 14-50 outlet isn't a deal breaker, that's probably the best option. Though I think it's better to run a 6-50 since you don't need to run the neutral and cars only need the two hots anyway. THis is a topic of much debate 'round these parts. Either way you'll need to buy the correct adapter from Tesla.

Do not put in a TT-30 outlet. Tesla doesn't sell a TT-30 adapter (though third parties do).

I'd suggest sticking with the current 5-15 outlet and Supercharging at first, and then evaluating.

 

[Webeevdrivers]

If the TT30 option was cheap enough I would consider that. We own an RV lot with an available TT30. (Coach plugs into a14-50). You’ll get about 3kw from a TT30 so about half a charge overnight. Literally twice as fast as a standard 15 amp socket. 95 percent of the time that is adequate for us as we tend to always operate on the top half of the “tank”. The aftermarket TT30 works fine.

JMHO

 

[LevelHeaded]

Hi all,

I've posted this months ago on Reddit and other EV related forums, but now that I am getting more serious about ordering a Model Y, I need to figure out if I can run with this...

I am considering the LR AWD Model Y with the basic 19" Gemini wheels when my lease ends on my current ICE car. That will happen sometime around now (summer) next year, but could be sooner depending on lease buyback/trade-in offers. At the very latest, it will be returned December of 2021. Other options I might add include the trailer hitch for a bike rack, and possibly changing to Black or MSM paint.

I drive around 20 miles for work (round trip), which is a mix of city and highway. I am expecting, pessimistically, around a 300 Wh Mile, and hoping to be surprised closer to a 250 Wh Mile. I have two kids that are involved in town sports, which usually adds less than 5-10 miles to the day's total a few (2 or 3) nights per week.

During the summer, I'll find myself driving to the shore areas around once a week, occasionally commuting from there, which is about 60 miles each way. There are lots of Supercharging options both near work and on the way between that are convenient enough that I won't be annoyed if I had to stop there for a few minutes. I'll also have destination charging (120V15A outlet) available at all points if I'm in a pinch.

My house is nearly 100 years old, and while the electrical panels and wiring have been upgraded over the years, it would require another panel replacement to allow 240V charging - which I've checked with 3 different electricians. The panel install estimate is somewhere in the mid to high teens ($1500 was low, $1800 was highest) but did also include a 14-50 circuit run of about 30 feet plus the outlet. I would probably consider going for the HWC if I went this route, which would then add an additional $500.

I'm looking at either having a 120V20A 5-20 or a 120V30A TT-30 circuit & outlet installed. The cost is expected to be somewhere around $300 to do so. In my garage, I have a 120V15A outlet (5-15) that I'd plan to just use in the interim. I'd probably have to figure out a way to use a halved PVC pipe to protect the wire from the garage door, or I'd have to figure out a way to drill a hole large enough for the cord to extend through with some type of escutcheon plate to stop critters from having easy access.

I work shift work, which has the benefit of it literally being an 8 hour work day. I will have the means to charge at minimum 12 hours between commutes. I park in a 2x2 (4 car) driveway, we do not have a large enough garage for anything bigger than a motorcycle due to home layout.

Also, I don't have "time of use" pricing from my utility. We've got tiers of pricing based on how much you use, divided into supply and delivery components. I pay roughly 17 cents per kWh, and with increased use it does jump to about 18 cents per kWh with rounding.

Thoughts:
*I am assuming 20% efficiency loss for the 120V circuits, though my understanding is that this overhead is fixed and decreases with an increase amperage, and again, I am "pessimistically" assuming a 300 Wh mile.

1. 120V15A Outlet in Garage - 120V*12A = 1440 W * .80 = 1.152 kW = 3.84 miles range per hour

• benefits: already installed, no extra cost here, adapter comes with car.
• negatives: have to figure out a way to get the cord from garage out of garage.
• slow charging - gains of 46 miles per day with 12 hours charging.

2. 120V20A Outlet near garage - 120V*16A = 1920 W * .80 = 1.536 kW = 5.12 mrph

• benefits: significantly faster charging, would be easier to access since installed outside
• negatives: installation cost, adapter needed for purchase
• better charging - gains of 61 miles per day with 12 hours charging

3. 120V30A Outlet near garage - 120V*24A = 2880 W * .80 = 2.304 kW = 7.68 mrph

• benefits: fastest 120V charging I can get, no electrical panel upgrade needed
• negatives: third party EVSE adapter needed, installation costs.
• better charging - around 90 miles per day with 12 hours charging

So, I'm a little torn here. Part of me wants to just run off of the standard 5-15 outlet, and if for some reason the garage plug gets frustrating, I could either hire an electrician to run an exterior outlet or I could try to do it myself and expand the existing outlet. I only drive 25 miles per day around 5 days a week, so over the course of a whole week:

25 * 5 = 125 miles driven weekly; charging 12 hours @ 120V*12A for 7 days would replenish 322 miles of range.

What's the best way to weatherproof the adapter itself? I am expecting a Taymac plastic box for the outlet itself if installed outside, but what solutions can I use for an enclosure for the MC? Ideally I'd like to have some type of plastic or wooden "box" that's waterproof and mounted to the side of the house for the MC to stay in and be sheltered, and large enough I could hang the cord underneath it as well.

I have an electrify america station nearby that has a Chademo, but I'd need to buy the adapter. I also could use Superchargers as needed, as well...

Thanks, all.

Make sure to account for
1. Range loss due to season (driving in cold and heating battery during while parked during winter, cooling battery while parked during summer).
2. Charging efficiency loss due to season (heating/cooling of battery prior to/while charging)

Note that these are amplified if vehicle is not garaged, and I think their effects may be greater than your MOST pessimistic calculation of 300 wh/mi and 80% charging efficiency. I’d calculate all your options at a bigger handicap.

 

[SSedan]

A TT30 would be great if you never see freezing temps.
If you see modest freezing temps a 14-30 240amp dryer outlet might be good enough, if your weather gets down to 0f then I would consider a 14-50 necessary.

Cold dramatically increases consumption, short trips make it worse because of repeated cabin warming cycles.

 

[Jbuntz]

Hi all,

I've posted this months ago on Reddit and other EV related forums, but now that I am getting more serious about ordering a Model Y, I need to figure out if I can run with this... I would consider converting a 15A Outlet to 240v.

I am considering the LR AWD Model Y with the basic 19" Gemini wheels when my lease ends on my current ICE car. That will happen sometime around now (summer) next year, but could be sooner depending on lease buyback/trade-in offers. At the very latest, it will be returned December of 2021. Other options I might add include the trailer hitch for a bike rack, and possibly changing to Black or MSM paint.

I drive around 20 miles for work (round trip), which is a mix of city and highway. I am expecting, pessimistically, around a 300 Wh Mile, and hoping to be surprised closer to a 250 Wh Mile. I have two kids that are involved in town sports, which usually adds less than 5-10 miles to the day's total a few (2 or 3) nights per week.

During the summer, I'll find myself driving to the shore areas around once a week, occasionally commuting from there, which is about 60 miles each way. There are lots of Supercharging options both near work and on the way between that are convenient enough that I won't be annoyed if I had to stop there for a few minutes. I'll also have destination charging (120V15A outlet) available at all points if I'm in a pinch.

My house is nearly 100 years old, and while the electrical panels and wiring have been upgraded over the years, it would require another panel replacement to allow 240V charging - which I've checked with 3 different electricians. The panel install estimate is somewhere in the mid to high teens ($1500 was low, $1800 was highest) but did also include a 14-50 circuit run of about 30 feet plus the outlet. I would probably consider going for the HWC if I went this route, which would then add an additional $500.

I'm looking at either having a 120V20A 5-20 or a 120V30A TT-30 circuit & outlet installed. The cost is expected to be somewhere around $300 to do so. In my garage, I have a 120V15A outlet (5-15) that I'd plan to just use in the interim. I'd probably have to figure out a way to use a halved PVC pipe to protect the wire from the garage door, or I'd have to figure out a way to drill a hole large enough for the cord to extend through with some type of escutcheon plate to stop critters from having easy access.

I work shift work, which has the benefit of it literally being an 8 hour work day. I will have the means to charge at minimum 12 hours between commutes. I park in a 2x2 (4 car) driveway, we do not have a large enough garage for anything bigger than a motorcycle due to home layout.

Also, I don't have "time of use" pricing from my utility. We've got tiers of pricing based on how much you use, divided into supply and delivery components. I pay roughly 17 cents per kWh, and with increased use it does jump to about 18 cents per kWh with rounding.

Thoughts:
*I am assuming 20% efficiency loss for the 120V circuits, though my understanding is that this overhead is fixed and decreases with an increase amperage, and again, I am "pessimistically" assuming a 300 Wh mile.

1. 120V15A Outlet in Garage - 120V*12A = 1440 W * .80 = 1.152 kW = 3.84 miles range per hour

• benefits: already installed, no extra cost here, adapter comes with car.
• negatives: have to figure out a way to get the cord from garage out of garage.
• slow charging - gains of 46 miles per day with 12 hours charging.

2. 120V20A Outlet near garage - 120V*16A = 1920 W * .80 = 1.536 kW = 5.12 mrph

• benefits: significantly faster charging, would be easier to access since installed outside
• negatives: installation cost, adapter needed for purchase
• better charging - gains of 61 miles per day with 12 hours charging

3. 120V30A Outlet near garage - 120V*24A = 2880 W * .80 = 2.304 kW = 7.68 mrph

• benefits: fastest 120V charging I can get, no electrical panel upgrade needed
• negatives: third party EVSE adapter needed, installation costs.
• better charging - around 90 miles per day with 12 hours charging

So, I'm a little torn here. Part of me wants to just run off of the standard 5-15 outlet, and if for some reason the garage plug gets frustrating, I could either hire an electrician to run an exterior outlet or I could try to do it myself and expand the existing outlet. I only drive 25 miles per day around 5 days a week, so over the course of a whole week:

25 * 5 = 125 miles driven weekly; charging 12 hours @ 120V*12A for 7 days would replenish 322 miles of range.

What's the best way to weatherproof the adapter itself? I am expecting a Taymac plastic box for the outlet itself if installed outside, but what solutions can I use for an enclosure for the MC? Ideally I'd like to have some type of plastic or wooden "box" that's waterproof and mounted to the side of the house for the MC to stay in and be sheltered, and large enough I could hang the cord underneath it as well.

I have an electrify america station nearby that has a Chademo, but I'd need to buy the adapter. I also could use Superchargers as needed, as well...

Thanks, all.

Hi all,

I've posted this months ago on Reddit and other EV related forums, but now that I am getting more serious about ordering a Model Y, I need to figure out if I can run with this...

I am considering the LR AWD Model Y with the basic 19" Gemini wheels when my lease ends on my current ICE car. That will happen sometime around now (summer) next year, but could be sooner depending on lease buyback/trade-in offers. At the very latest, it will be returned December of 2021. Other options I might add include the trailer hitch for a bike rack, and possibly changing to Black or MSM paint.

I drive around 20 miles for work (round trip), which is a mix of city and highway. I am expecting, pessimistically, around a 300 Wh Mile, and hoping to be surprised closer to a 250 Wh Mile. I have two kids that are involved in town sports, which usually adds less than 5-10 miles to the day's total a few (2 or 3) nights per week.

During the summer, I'll find myself driving to the shore areas around once a week, occasionally commuting from there, which is about 60 miles each way. There are lots of Supercharging options both near work and on the way between that are convenient enough that I won't be annoyed if I had to stop there for a few minutes. I'll also have destination charging (120V15A outlet) available at all points if I'm in a pinch.

My house is nearly 100 years old, and while the electrical panels and wiring have been upgraded over the years, it would require another panel replacement to allow 240V charging - which I've checked with 3 different electricians. The panel install estimate is somewhere in the mid to high teens ($1500 was low, $1800 was highest) but did also include a 14-50 circuit run of about 30 feet plus the outlet. I would probably consider going for the HWC if I went this route, which would then add an additional $500.

I'm looking at either having a 120V20A 5-20 or a 120V30A TT-30 circuit & outlet installed. The cost is expected to be somewhere around $300 to do so. In my garage, I have a 120V15A outlet (5-15) that I'd plan to just use in the interim. I'd probably have to figure out a way to use a halved PVC pipe to protect the wire from the garage door, or I'd have to figure out a way to drill a hole large enough for the cord to extend through with some type of escutcheon plate to stop critters from having easy access.

I work shift work, which has the benefit of it literally being an 8 hour work day. I will have the means to charge at minimum 12 hours between commutes. I park in a 2x2 (4 car) driveway, we do not have a large enough garage for anything bigger than a motorcycle due to home layout.

Also, I don't have "time of use" pricing from my utility. We've got tiers of pricing based on how much you use, divided into supply and delivery components. I pay roughly 17 cents per kWh, and with increased use it does jump to about 18 cents per kWh with rounding.

Thoughts:
*I am assuming 20% efficiency loss for the 120V circuits, though my understanding is that this overhead is fixed and decreases with an increase amperage, and again, I am "pessimistically" assuming a 300 Wh mile.

1. 120V15A Outlet in Garage - 120V*12A = 1440 W * .80 = 1.152 kW = 3.84 miles range per hour

• benefits: already installed, no extra cost here, adapter comes with car.
• negatives: have to figure out a way to get the cord from garage out of garage.
• slow charging - gains of 46 miles per day with 12 hours charging.

2. 120V20A Outlet near garage - 120V*16A = 1920 W * .80 = 1.536 kW = 5.12 mrph

• benefits: significantly faster charging, would be easier to access since installed outside
• negatives: installation cost, adapter needed for purchase
• better charging - gains of 61 miles per day with 12 hours charging

3. 120V30A Outlet near garage - 120V*24A = 2880 W * .80 = 2.304 kW = 7.68 mrph

• benefits: fastest 120V charging I can get, no electrical panel upgrade needed
• negatives: third party EVSE adapter needed, installation costs.
• better charging - around 90 miles per day with 12 hours charging

So, I'm a little torn here. Part of me wants to just run off of the standard 5-15 outlet, and if for some reason the garage plug gets frustrating, I could either hire an electrician to run an exterior outlet or I could try to do it myself and expand the existing outlet. I only drive 25 miles per day around 5 days a week, so over the course of a whole week:

25 * 5 = 125 miles driven weekly; charging 12 hours @ 120V*12A for 7 days would replenish 322 miles of range.

What's the best way to weatherproof the adapter itself? I am expecting a Taymac plastic box for the outlet itself if installed outside, but what solutions can I use for an enclosure for the MC? Ideally I'd like to have some type of plastic or wooden "box" that's waterproof and mounted to the side of the house for the MC to stay in and be sheltered, and large enough I could hang the cord underneath it as well.

I have an electrify america station nearby that has a Chademo, but I'd need to buy the adapter. I also could use Superchargers as needed, as well...

Thanks, all.

I would consider converting a 15A Outlet to 240v.

 

[MikeHolliday]

Why not simply take the money you save with the new $3,000 price drop and run a 60 Amp Circuit to the location. The Tesla Wall Connector is 100% waterproof or install a NEMA 14-50 until you decide if you want a Gen3 Wall Connector...

 

[MY-Y]

Look up tandem breaker. You can also likely combine two existing circuits on a single beeaker depending on the load.

 

[MikeHolliday]

MY-Y, I believe what he stated is that he had more than one Electrician look at the system. You cannot just simple put an additional circuit into a Load Center (Breaker Box). For example, if you have a 100 Amp supply to your house and you have Air Conditioning and Electrical Applicances there will not be enough spare Amps to safely add an additional 240 volt circuit. Just because there is space in the Box for more breakers does not mean that they can be added. The reason that we have building codes is so that people don't do something that jeopardizes the safety of their home...

 

[MY-Y]

I agree about the code and safety, but don't agree adding a circuit will cause a safety issue. If you overload a panel, it will just trip the breaker. I have well over 2x my panel capacity in breakers, yet draw less than 15% of my panel capacity most of the time.

 

[Pilot1226]

Hi all, just got out of work and had a chance to read over your replies.

I live in northern NJ, about 10 miles west of NYC. We are very suburban - highways and paved roads everywhere.

We do get snow over the winter, but typically temperatures don’t get below freezing until January and get warmer near the end of February. It’s a very rare event to be below 0F.

I’ve watched several YouTube videos by Evan Michiels(?) who has done tests in the mountains of NC with temperature in the teens and 20’s. He still managed the normal 120V15A socket to generate 4-5 miles of range per hour over night, but it did slow from time to time to heat the battery before adding range.

As discussed in my original post, I can’t add tandem breakers. I have no slots left to add new circuits. I can’t combine any. My choices are to decommission and replace that 20A circuit used for the house fan or replace the whole panel.

Since I have access to Superchargers I think I’m going to see what the 120V15A (@12A) gets me. No sense in making mountains out of molehills. I did have a load test done on the amperage and even though I have 100A service, my central air uses around 28-30 continuous and I have all gas appliances... My lights are entirely LED’s and I have a significant amount of available amperage for charging. I think the 5-20 would be enough per the TeslaTap despite the colder weather. It would be less inconvenient and less stress than making sure I am connected and charging as much as possible but I am pretty sure the 5-15 would be “okay” but not “great”...

I can post some photos of the breaker box and subpanels over the next day or two.

 

[GWord]

How old is your current panel board? Tandem breakers may be an option to make some space, if it’s new enough. Otherwise I would strongly consider converting an existing circuit to 6-20 for a decent charge rate. That would insure you could always get full overnight, if needed.

 

[Uncle Paul]

Your AC may only use 28-30 amps continous, but it may use over twice that in surge to start.

Homeowners tend to look at a best case scenario for putting as much as possible in place, while electricians and code wants to look at the worst case possible and protect that from burning down your house and neighborhood.

Tesla on a 240V line flows tremendous amounts of current for very long periods of time. If it is drawing 40 amps, your home draws it's normal load, the dish washer or washing machine kicks on and your refrigerator surges to a start...One of your old circuit brakers falis...

 

[Pilot1226]

Hi, here's some photos of the breakers for reference. I'll check this again after work today with some more thoughts.

The third picture on slot 7 on the left side is the 20A breaker that corresponds to the "whole house" fan I will remove to make room for a 120V 30A or 20A circuit. The run will be about 5 feet to the outside for the outlet.

 

[LevelHeaded]

IMO, if you’re going all-in on BEV technology (i.e. forking the $60k over to get the vehicle), you should budget the inclusion of an adequate home charging setup (240V/30+A). Not necessarily right away if you can’t swing it or for some other reason, but it should be part of the mid/long term plan.

Context: I had only 15A service for about a year with my M3 in a rental in Seattle (more temperate than your location by the sounds of it), and it became clear that investing in a BEV without the proper charging setup is like building a house in Phoenix, AZ and not installing an air conditioner.

edit: also, upgrading your panel isn’t without upside. Home buyers love to see modernized electric service.

 

[M3BlueGeorgia]

Hi, here's some photos of the breakers for reference. I'll check this again after work today with some more thoughts.

The third picture on slot 7 on the left side is the 20A breaker that corresponds to the "whole house" fan I will remove to make room for a 120V 30A or 20A circuit. The run will be about 5 feet to the outside for the outlet.

View attachment 564130 View attachment 564131View attachment 564134 View attachment 564136

Also consider a 6-20 outlet (240v/20A), sometimes called a "welder" outlet. Better than 120v/30A, plus its a standard supported outlet by Tesla.

I think you need to add up your existing amperage usage and figure out the most you can fit, and if you are leaning towards 120/30, see if you can, instead, go to 240/20. If you are hard limited, go to (6-15) 240/15 instead of 120/30.

 

[Pilot1226]

The limitation I have isn’t the available amperage, it’s the breaker slots. I cannot add a 240V to this setup.

 

[Puma2020]

Your plan to start with 120V 15/20/30A is feasible especially with Superchargers nearby. I'd skip the Chademo adapter as EA will charge a LOT more than the Superchargers. So that saves $500 plus EA expensive charging costs. Once you get an idea how many times you have to supercharge, you'll know whether to upgrade your electrical. Adding an EV port may help sell the house later, but probably not much.
Superchargers will charge roughly $0.28/kWh. Not sure what you home rate is, but let;'s use $0.14/kWh as an example and it makes the math easier. If you find yourself supercharging 100 kWh each week, that means re-doing the home electrical would save you $14 each week. I think that's correct. $1500 for the rework / $14 per week would mean about 107 weeks to break even. After those 2 years, you would continue to save over supercharging. However, your initial plan gives you time to experience what you need and WHERE you are going to park so you know where to install the plug.
If you go for the electrical upgrade, also plan on if you add solar (even if you never get to it). Battery systems for solar do not want high amp loads on the battery system. So you'd want to re-do the electrical (since you are doing it anyway) so most of the house could be tied to a battery system and the big loads (A/C, Electrical Dryer, etc...) are on a different panel.

 

[SilverSp33d3r]

Use NJ tax credits/ rebates and get 240v charging.

 

[Pilot1226]

Yes, the state does give a one-time credit or rebate up to $500 towards EVSE installations. I’m factoring this into the decision as well. I don’t think solar is in the cards for us due to expense and discontinuation of some state incentives (SREC’s helped reduce the cost by about $200 per month for 10 years) ...

I don’t disagree that the 6-20 should provide nearly all the energy I would need.

I was hoping to use the $500 down the road towards the HPWC, but as you see, I’d have to upgrade it to 240V regardless first.

@Puma2020 My home electric rate is about $0.17-0.18 per kWh for the combined supply and demand cost, without time of day (they don’t offer it)...

I am expecting to charge maybe 100 kWh per month at most. Probably closer to 25-50 kWh per month and literally 0 outside of summer with the longer shore commutes. So, figure probably around 600 kWh per year at SC’s, which at 28 cents would cost around $75-80 per year more over home charging costs. That would take a long time to make up for the panel install, for sure.

Like, 18.75 years. I’m probably not going to be in that house anymore.

Again with 120, everything is wholly depending on how the charging does in winter. Everything I have seen for the NYC area suggests that it will gain charge overnight in winter. So, will have to play it by ear until I hear something else.