I was actually glad I put in an 80amp HPWC... one time in 4 months

[BrettS]

So I got my 2015 Model S about 4 months ago and it came with dual chargers. I decided to put in an HPWC and went back and forth about how much power to give it. I didn’t want to overspend, but I also wanted to take advantage of the dual chargers since they were there. In the end it wasn’t significantly more to put in a 100 amp circuit to be able to charge at 80 amps, so that’s what I did.

As people predicted, I usually charge at night and I really would have had no problems with a lower amperage connection most of the time, but today I got in the car and started to run an errand and I was a bit shocked when I looked at the navigation screen and saw that it was precicting that I would arrive at my destination with 22% left. I looked down and realized that I only had a 35% charge because apparently I had completely forgotten to plug the car in last night.

I made it to my destination and back home with 7% left and I only had an hour before I needed to take another 50-60 mile round trip. Luckily with my 80 amp HWPC I was able to get enough charge in during that hour to make me feel comfortable about making that second trip without having to change my plans at all.

For those of you trying to make that decision it’s probably worth noting that I really only needed all 80amps once in the four months that I owned the car (and if I had actually remembered to charge last night I wouldn’t have needed it at all), but in this once case, at least, it was nice to have.

 

[thecloud]

Was the supercharger (Turkey Lake) too far out of the way to be an option?

 

[X Fan]

^^^^
don't know his specifics, but Orlando's a huge geographical city with often SoCal like traffic patterns and the SC is located on the limited access Turnpike.....exiting FL, I make a point to bypass Orlando.....

 

[BrettS]

Was the supercharger (Turkey Lake) too far out of the way to be an option?

Well, the long version was this: My first trip was up to daytona to buy some fish for my fish tank, then I needed to go home and take about an hour to acclimate the fish and get them in the tank, then my second trip was to the theater to see a movie, so I had a specific time I needed to be there.

I was actually maybe 5 or 10 minutes from the port orange supercharger while I was in Daytona, so I could have used that if I was desperate, but I wouldn’t have had time to get home and get the fish in the tank, then make the movie if I had.

In the end it wouldn’t have been the end of the world if I had to go to a later movie and charge longer at home or hit the supercharger for a bit, but it was nice to have the power at home to get the charge I needed in the time I had.

 

[Lasttoy]

Orlando is bad. I accidentally got low, went to SC. Lady was jerk. But she agreed to charge it enough for me to get home.
Tourist mecca of FL and no chargers. Just plain stupid.

 

[EV-lutioin]

Orlando is bad. I accidentally got low, went to SC. Lady was jerk. But she agreed to charge it enough for me to get home.
Tourist mecca of FL and no chargers. Just plain stupid.

I see three new Superchargers on tap for Florida, hopefully that will help a little.

 

[aesculus]

Usually the incremental cost for 40 to 80 is just the cable. Everything else is a wash or a small amount of money. Breakers are cheap and the HPWC is the same.

So if your cable run is not too long and you have the ability to put in the larger breaker in the panel, it's generally a no-brainer IMHO.

 

[BrettS]

Orlando is bad. I accidentally got low, went to SC. Lady was jerk. But she agreed to charge it enough for me to get home.
Tourist mecca of FL and no chargers. Just plain stupid.

For what it’s worth, the Orlando service center is where I go for work on my car. I’ve only been there a few times, but everyone I’ve delt with there has been very nice and helpful. They don’t have any public superchargers at the service center, so it sounds like they did you a favor by charging your car. I’m not sure I’d speak badly about the people who took time out of their day to help get your car charged and get you on your way.

Depending on which way you were going you could have gone to the turkey lake super charger that’s about 20 miles south of the service center or the Port Orange supercharger that’s 50 miles north, or any number of public L2 chargers in the Orlando area if you were really desperate.

 

[electracity]

Usually the incremental cost for 40 to 80 is just the cable. Everything else is a wash or a small amount of money. Breakers are cheap and the HPWC is the same.

So if your cable run is not too long and you have the ability to put in the larger breaker in the panel, it's generally a no-brainer IMHO.

Putting a new 100amp breaker on a typical existing 200 amp service is going to be way outside NEC guidelines. The only exception would be homes that didn't need 200 amp service in the first place (1 AC, gas stove/dryer/heat).

 

[sandpiper]

So I got my 2015 Model S about 4 months ago and it came with dual chargers. I decided to put in an HPWC and went back and forth about how much power to give it. I didn’t want to overspend, but I also wanted to take advantage of the dual chargers since they were there. In the end it wasn’t significantly more to put in a 100 amp circuit to be able to charge at 80 amps, so that’s what I did.

As people predicted, I usually charge at night and I really would have had no problems with a lower amperage connection most of the time, but today I got in the car and started to run an errand and I was a bit shocked when I looked at the navigation screen and saw that it was precicting that I would arrive at my destination with 22% left. I looked down and realized that I only had a 35% charge because apparently I had completely forgotten to plug the car in last night.

I made it to my destination and back home with 7% left and I only had an hour before I needed to take another 50-60 mile round trip. Luckily with my 80 amp HWPC I was able to get enough charge in during that hour to make me feel comfortable about making that second trip without having to change my plans at all.

For those of you trying to make that decision it’s probably worth noting that I really only needed all 80amps once in the four months that I owned the car (and if I had actually remembered to charge last night I wouldn’t have needed it at all), but in this once case, at least, it was nice to have.

That's the sort of thing that happens to me once every 5-6 months - moreso in the winter. I'll have run down the car during the work day, need to leave on a long trip after work, and need to charge up to reach the first SC. I can get the 150 km I need in an hour and a half with my 80 amp charger. With the 32, I'd be waiting 4 hours and so I couldn't make the drive that day.

The high power charger is of no value until the day that you need it. I'm very happy that I got it.

 

[ReturnZero]

Putting a new 100amp breaker on a typical existing 200 amp service is going to be way outside NEC guidelines. The only exception would be homes that didn't need 200 amp service in the first place (1 AC, gas stove/dryer/heat).

Where can you find this out? Is there a limit to the total of the breakers on a 200 amp service panel? Or is it another limitation?

 

[BrokerDon]

Putting a new 100amp breaker on a typical existing 200 amp service is going to be way outside NEC guidelines. The only exception would be homes that didn't need 200 amp service in the first place (1 AC, gas stove/dryer/heat).

Actually connected loads can routinely exceed main service panel capacity. I see this all the time in the industrial buildings I've sold or leased in the past 36 years as a commercial real estate broker... and the homes I've owned. If your electrician does a "load calc" of all your existing loads adding a 100A breaker onto a 200 amp service will meet electrical code, pass electrical inspection. It will also work without a hitch as long as you don't turn on a bunch of other heavy loads while your Tesla is charing at 80A. Typically this isn't a problem since our Tesla charges overnight when all our other electrical loads are completely off or intermittent (HVAC). Using a "load calc" is how our 80A gen1 Tesla HPWC got installed 2 years ago on a 100A circuit breaker through a 100A sub-panel by a Tesla recommended electrician with electrical permits and inspection.

Like the OP, we've only charged at 80A twice: once when we forgot to plug in when we got home and another time when we had to leave unexpectedly after coming home with a mostly depleted battery. The rest of the time our dual charger equipped P85D recharges overnight at 50A or 60A which keeps the HPWC handle & Tesla charge port from getting really warm like it does at 80A. Cooler should equal longer electrical component life for our HPWC, cable, and P85D's dual chargers.

 

[electracity]

Where can you find this out? Is there a limit to the total of the breakers on a 200 amp service panel? Or is it another limitation?

Number of breaker is not an issue, AFAIK.

Many sources available. Google "residential electrical load". There are probably free apps that do the calc.

Personally I would not worry about going a little over the recommended max.

Installing a 100 amp circuit but throttling the charger (max amps is settable by dial in the charger) is an option. Active load control of AC units may be doable later if the full 80 amps is needed some day.

 

[SarahsDad]

I agree with the original poster - I have an 80A HPWC and rarely 'need' that extra charging, but one fall Saturday I took a drive up to the Blue Ridge Parkway and arrived back late that afternoon with about 40 remaining miles only to be reminded that we had dinner reservations in Charlotte in an hour, about 30 miles away. Would never had made it without the 80A HPWC…

 

[ReturnZero]

Number of breaker is not an issue, AFAIK.

Many sources available. Google "residential electrical load". There are probably free apps that do the calc.

Personally I would not worry about going a little over the recommended max.

Installing a 100 amp circuit but throttling the charger (max amps is settable by dial in the charger) is an option. Active load control of AC units may be doable later if the full 80 amps is needed some day.

Yeah I know the number of breakers isn't an issue (as long as they fit in the panel) I just wasn't sure what the actual allowable load would be. Can you only have 250 amp max theoretical load on a 200 amp breaker? Less? More?

I'll search for a calculator like you suggested, perhaps I'll be able to find one that does the math automatically.

 

[ReturnZero]

Basically all the calculators I've found in the past are for figuring out how big of service you need for your house. What I want to know is how far over the 200 amp service you're allowed to have breakers for. Perhaps it's just not that easy though.

 

[Rocky_H]

Basically all the calculators I've found in the past are for figuring out how big of service you need for your house. What I want to know is how far over the 200 amp service you're allowed to have breakers for. Perhaps it's just not that easy though.

It's not just an exact number you can state, because it all depends on what types of loads they are. Every load calculation is specific to each situation. Are they loads that only come on a certain times, that can be offset from the times of other loads? Are they lighting circuits? How much is the square footage of the house to calculate for the lighting and wall outlets? There are a lot of factors like that.

 

[davewill]

Basically all the calculators I've found in the past are for figuring out how big of service you need for your house. What I want to know is how far over the 200 amp service you're allowed to have breakers for. Perhaps it's just not that easy though.

It's the same calculation. It is not based on the breakers, it's based on the actual appliance loads you have. Put all your current loads plus the proposed charging circuit into the calculator. If the calculation comes in at 200a or less, you just need to find a place to add the breaker. It it's >200a, you either need to try a smaller charging circuit, eliminate some existing load(s), or upgrade the panel and/or service.

 

[animorph]

The load calculation is formalized, with standard approximations and assumptions, one of which is that not everything will be on and drawing maximum current at the same time. You can do it fairly well by yourself using an online calculator, but it would also be part of getting an electricians estimate. You do the calculation with your HPWC included and if it comes in at under 200A (or whatever your service is rated at) you're good to go. Or, with the HPWC you can adjust its current draw to whatever fits.

We have 200A service and were able to fit in a 100A HPWC circuit. It took the place of an unused 50A cooktop circuit. We have gas for that, the dryer, and the water heater, leaving enough for a full powered HPWC. Hopefully two HWPC's sharing the same 100A circuit when we get a Model 3.

 

[aesculus]

FWIW I was originally going to put in a dedicated meter for the HPWC. I applied for the permit and filled out a request to my utility (PG&E). They actually ran the load calcs for me based on times and noted when and how much my power consumption was. They noted that if I charged off peak (their EVA rate plan) I would never come close to maxing my 200 amps. So my electrician and I decided to manage it that way.

If I ever bake a turkey, run the spa, my two heat pumps and charge the car at the same time, I could be in jeopardy. But I am cognizant of that fact so whenever all those other items are in play, the car will not get charged.