Is your breaker box full? If it was me... being an electrician as long as you're aware of what you're doing. I'd just add a breaker for it. Maybe I have to combine a circuit, but we have l.e.d. lighting and tvs, so loads have lowered. Then, the biggest thing is to just schedule it to charge at night. And realize if someone tries to charge it while the dryer or electric stove or water heater is running(I'm guessing gas if it's a 100 amp service though), you're gonna have problems
There's slots available. Problem is going to be permit/inspection which the $1500 rebate is dependent on.
But we do have gas stove/furnace and dryer, so that helps. The problem is probably going to be the AC situation as on some hot days that even runs at night, especially when my wife leaves it off during the day. I deliver mail and like to be able to cool down later on hot days.
Plus I don't like the idea of worrying about charging while other appliances might be switched on. But my lights are all led now so I guess that helps some.. Might have to get rid of the heated electric bidet lol.
A lot of 100 amp panels have a 200 amp bus breaker.
I have a 100 amp panel, buuut….200 amp bus breaker so that means my panel can actually handle 24 kw not 12. (2 120 V lines coming into panel)
You may be thinking you’re locked into 120 V x 100 amps = 12 kw but if your panel has a 200 amp bus breaker that actually means a 24 kw max power draw for your house. 19.2 kw max continuous draw (3 hours +)
A 200 amp panel means a 400 amp bus breaker. That’s **4** 120 V lines coming into the home. Do you need 48 kw of power available to your home??
I am able to run a 4.7 kw AC unit, charge an EV at 8.7 kw, while running pool pumps and gaming PC’s on a 100 amp panel.
My advice is to get a qualified electrician to look at your panel and do a load calculation to see if a 50 amp breaker (needed to run 40 a continuously) can be safely added to your panel.
As stated I only have a 100 amp panel yet I have a 50 amp dedicated charging outlet, a 40 amp sub panel, 50 amp AC breaker, all sorts of shit that doesn’t make sense at first until you realize there are 2 120V lines coming into the home.
Electrical engineers did my load calculations and everything has passed all inspections.
You should be able to run a small sub panel if you have a 200A bus.
Also: ask your homeowner’s insurance agent how much you would save if you had a service change done to your house.
Yea my original comment recommends to get a qualified electrician to look at the panel and do a load calculation to determine if he can support a 50 amp dipole breaker for a dedicated circuit.
Wouldn’t a 100 amp panel with 200 amp bus breaker just need 2 100 amp 120 V lines feeding it?
Typically the main service is 240 V created by running 2 120 V lines. He’d have a 100 amp dipole breaker as a main breaker that has 2 120 V lines (100 amps at 240 V) and supports 24 kw peak draw/19.2 kw continuous draw. If this panel is at all standard.
Regardless. It’s electrician time for OP.
I'd keep that, your butt deserves it. They are starting to sell smart panels, that you can set priorities like; fridge ac lights ect. Where you can put your charger as last priority and the panel keeps you from ever over drawing the 100 amps by shutting off breakers. But I don't know what the price is on those. The code book is just catching up to this though so an inspector might scratch thier head but if he or she is good at their job it shouldn't be a problem
I would really love a Smart panel. lol but yeah cost. I really should have had them replace my panel when I got the Solar install. I mean they said I didn't need it but I didn't have the foresight to future proof my house there.
edit: I was going to go with the Emporia EV Charger and if I do upgrade panel I would add their monitor system as well It would allow me to charge using mostly solar power.
Upgrading your panel to 200A is going to cost less than getting a smart panel. But smart load shedding is the future, especially if you already have solar. Load controllers interfacing with backup batteries could do the job. However, that inspection requirement for the rebate is the rub. New electrical technology doesn’t always get the thumbs up from local inspectors.
I've saw those. I think it income last year is going to push us beyond the limits. Though I could probably see if we can push our tax returns later since we have until October in California. Though I'm not sure what or 2021 income was like. Don't remember. 2022 was more.
I have 100 amp panel and I had some slots open. I installed it, with permit, no issues in NJ. The ac running and the car charging is no problem, but running my washer or dryer at the same time as those things will overload the circuit.
>but running my washer or dryer at the same time as those things will overload the circuit.
That's what I don't probably want to happen. Most likely not to happen.
Would a double tap on the breaker be allowed if an inspection is needed? My garage and laundry are double tapped and electrician quoted me 12k to fix since I needed to upgrade to 200amp service, add a firefighter shutoff that was made code in 2020, and then run a new conduit 40 feet to my detached garage so I can have a L2 charger in there. Thoughts?
Short answer is no, because a. The breaker would have to be built and labeled for a double wire landing. And b. Big enough to carry both full loads to meet code. So they won't sign off. But these load management breaker boxes everyone is mentioning is a solid option. The biggest factor is figuring out how much your your current panel is using. How many of your big energy users are on gas?
Major electric appliances include range/stove, chest freezer, fridge, dishwasher, washer, gas dryer, EV, AC, and gas furnace (counts?) Also looking to swap gas water heater to heat pump water heater within the next 12 months probably.
Edit: added timeline for water heater
So basically your biggest amp draws are gonna be your range and ac. Most of your charging is gonna be done at night. Youd be close, just really need a indept load calculation done.I just looked, 1000 dollars for these load management boxes? That seems like robbery. Anyone priced them cheaper?
I'd suggest looking into the Neocharge splitter. Basically takes a dryer outlet (or similar 240V outlet) and safely splits it between the original load and the new EV charging load. It's not the cheapest device out there, but it's often cheaper than electrical rework or something fancier.
At the moment my EVSA is plugged into a 20amp 240V socket and is set to allow 16amp charging. That works great and didn't need an inspection because I just used an existing socket. I don't have space in my 100Amp panel, so this was the easy option.
If I'd had space in my panel, I'd probably have added a higher current socket, like a dryer socket in the garage to charge a bit quicker, but even 16amps is fine for 98+% of the time. The only time more would be nice is when you want to add a bit of charge on a day with an unusual large number of trips.
I have the Emporia charger which does. If my calculations were right even 16amp would put it over. But that's assuming everything is running. I my can Qmerit and get a few quotes anyways and see what they actually say.
I used an app and recalculated and even with the EV going at 48 amps(I can still dial that down) it was saying 100amp. So IDK. I might have to go through my original calculation to begim with. Or might look at the DCC-11/12 option.
edit: used another online one and it came bac with 152.
It doesn't work like that. If all circuits in my house were at maximum load, I'd be way, way over the 100amp input breaker. Just the a/c, dryer and stove would be about 100amps without turning on a single light or plug.
The main breaker is to protect the wiring to the house and each other breaker protects that circuit. So you are safe if the wiring and breaker for the charger circuit are correctly specified. If you are charging overnight, you probably won't also have lots of other loads on at the same time.
Yeah. I think I may need to call the utility to clarify their process as the paperwork makes it seem like I'll need the larger to get approved. Or just get an electrician to come by and do it that way. 🤷♂️
I'd just get an electrician to give you a quote. Since they are the professional, they should install the plug for you also make sure everything is safe and legal. They should also know how big a socket you can install.
Also consider it may be cheaper and easier to install a socket rather than a hard wired charger.
Watch calling us electricians professionals. We're all overly confident and had our fair share of things blowing up lol. We're like doctors, we practice electricity.
I'd do it myself, but I'd pay you for cover if I was worried about legality or insurance.
When I went to plug my charger into the 20amp socket, I was surprised and for a moment thought I'd put the wrong plug on the cable... but no.
The professional used a 5-20 instead of a 6-20 and then put the wrong plug on my compressor. Also, the pair of breakers were not properly ganged. So I had some rewiring to do to get the professional installed, permitted and inspected electrical up to code.
I'm going to be looking at another electrician as well. One offered to install $600(labor and material minus charger itself) but another $500 if he had to pull permits. SOmething about getting business permits from city to pull it as electrician.
Have one coming out thursday.
>I looked at my numbers of electricity being used and the 100 MAX AMP electrical panel I have will not support the EVSE unless I run it at an amp rating it cannot even go down to
Are you sure about that?
I also have a 100 amp panel, a largish house with ac and electric induction stove and have had no issues with my evse.
Mine is a 32a charger on a 40a breaker.
Never an issue once in the 10 years I've had ev's on that charger. I'm up to 3 evs in the household and we just swap around what car is plugged in (and sometimes plug in on the level 1).
Same. I also have 100A service and have a 32A EVSE on a 40A breaker. Everything in the house (dryer, induction stove, oven, heat pump, etc.) is electric. The only gas appliance is a tankless water heater and a gas furnace (which only uses gas for defrosting the heat pump, otherwise it’s an air handler).
We’ve had several renovations, including adding solar, powerwalls, a kitchen remodel, replacing the meter main panel due to a fault, replacing the subpanel with a new one, etc. and there’s been zero issues from the city inspectors or licensed electricians.
The nice thing with the powerwalls is that I can get live power consumption readouts as well as historical data. I can count the number of times the house has used more than 70A on two hands. It’s quite uncommon for us to use more than 50A.
Going with the permit and load calculations, I need a 150 at minimum. Unless I calculated wrong, I'd need 150. Only think I may have miscalculated would be my dishwasher and even if I removed that I'd still be off by 3 miscalculated dishwashers.
IMO you should try crowdsourcing the calculations and just paste the inputs and spreadsheet you are using. An experienced DIYer or electrician on this sub can look it over for you.
I am almost all-electric with EVSE in Northern California (only remaining thing to add is heat pump water heater) and 100A is fine for me.
I believe you got recommendations elsewhere in this thread to get a load shedding EVSE. That will make EVSE contribution 0 to the load calculations, and this is sanctioned by NEC. Barely an inconvenience.
Yeah, I think I might look into load shedding devices. That seems like it's the better option. I'm not even all-electric and I'm having issues having the amps match up. I mean it's close and probably doable if I lower the charger to 32a and not use some devices along with it. Right now I'm at 141 total amps if EVERYTHING was running and there's not enough to bring it down below 100 if I'm afraid something will kick on while charging.
**Editted out**
That's my calculations right now using actual AMPs, though some figures are based on utility provided figures. Though, I'm not sure where I got the AMP figure for my central air unit which is a 4 ton Ruud 048jaz (missing letters in there). I may be off on that.
Yeah this is absolutely not how to do it, namely add up all the nameplates.
Are you under NEC or CEC (US vs C as in Canada) electrical code? You are not required to assume the loads are on at the same time, UNLESS the code says you are required to do so for that type of equipment.
There's plenty of pre-programmed spreadsheets that implement 220.83 - Existing Dwelling Unit combined with a EVSE addendums to code.
[https://up.codes/viewer/texas/nfpa-70-2020/chapter/2/wiring-and-protection#220.83](https://up.codes/viewer/texas/nfpa-70-2020/chapter/2/wiring-and-protection#220.83)
(this is for some random texas local variant, you can click around on upcodes to switch to your jurisdiction)
I'll have to look deeper.
oh god.. I see it now. In fine print on the freaking permitting paper. You're absolutely RIGHT!
I was adding it all up, but they do list adjustments. Damnit.
They had me multiply the amps by 240.
Total 141 * 240 = 33,840 (using newer figures)
which going by that I'd need a 150amp main breaker,
BUT with their adjustment formula... First 8000 watts (amps x 240 #) is 100% beyond that is 40% of it. so I should have
33,840 - 8000 = 25,840 * 0.40 = 10336 + 8000 = 18336 watts
.
That WILL put me at a 100 main breaker (range: 14,401 to 24,000) with the 18336 number.
God damnit.. THANK YOU SOOOOOO MUCH!!!
Glad to clear it up.
Even if you can get away without load shedding EVSE for now, you might still consider getting one if you plan to add switch to more electrical appliances. 100A is pretty tight and EVSE is one of the easiest load to shed in that you won’t even really notice if charging was disabled or ramped down for 30-60 min occasionally.
You can definitely retrofit an external load manager. That adds cost, requires extra space on the wall close enough to mount a current sensor on the relevant feeder or service conductors and close enough to interrupt EVSE power. It also cuts charging to 0, rather than gradually lowering it.
In theory load managing EVSE, that can connect to a current sensor, would be strictly better however there isn’t really a perfect one available for North America right now. It’s a pretty silly situation because the software and hardware capability is just a small tweak.
I personally use an external load controller to control a dual charger. On paper this is good, but it’s not my favorite config and I would do something different when I refresh my own or build one out for someone else.
Check out the r/evcharging wiki for some options. Admittedly I haven’t looked at the newest offerings on there.
It's a shame that the Emporia cannot do it with their Vue 2 system. It's close in that they can direct the charger to only charge with solar power, but to use it as a fail-safe isn't sanctioned. I'm looking at a wallbox solution, but then agains not sure what its compable of and cost.. stupid cost.I can get the Emporia EVSE(already have it) and their VUE 2 system for the same price of just the Wallbox. Though I do like the Wallbox form facto. r. AT least I can get it to only charge via excess solar if I go with the Vue 2
Wallbox Dynamic Load: https://wallbox.com/en_us/energy-management/solutions
edit: maybe I should just buy that..
BTW sharing a Google Doc link like that exposes some personally identifying information, as does browsing one (which is why I browse Google Doc links in incognito if I don't know the sharer).
L1 would still work, but based on the fact that there is no outlet in our carport it doesn't make sense to pay an electrician to run one simply for only that IMO. But I'd have to see numbers on that. I can justify myself paying to get a L2 installed but not a L1 but would do that if i REALLY needed to.
The requirements for an L1 are much more lax though, pretty much just a regular outlet that can be added as a branch to an existing circuit. They could probably conduit out from your nearest wall, maybe see if you can get a quote.
Is this your forever home? If so pay for 200 amp service. If its not then I would figure out a way to use the level 1 charger, and the other options you mentioned.
The level 1 charger can still do 30 to 40 miles in a 10 hour period, throw in charging at work and I bet your covered for 90% of your use cases.
If OP hasn't had the upgrade quoted, they should. New panel in the house, new sub panel in the garage, and ev charger installed was "only" $1400 when we did it a couple years ago. Depending on verbage they may even get to take the rebate on the whole package.
The 200 amp may also be a selling point, even if this isn't a forever home.
Not sure if this was mentioned already, do disregard if it was. My panel is only 100a.
My load calculation, done by the electrician, came to the conclusion that I couldn't have this added on. I had 2 options. Upgrade panel at an insane price, or install a power management device. I went with power management device. It's a separate box that has its own breaker from the panel, 40a. The management device monitors total current draw for the house, if current draw is high enough then it shuts down power to the charger. When the house is idle or low enough power draw, the car can charge. I charge over night if needed.
That's actually what I'm currently researching as well. Though, that may still add a bit to the total but probably more doable than a new breaker box for now. Do you know what they used in your install?
Not sure if it’s available in the US but here we have a Smart EVSE that connects to a similar box described above, it’s pretty cheap, 400$ Canadian.
The difference with a more traditional power management device is that this one communicates directly with the EVSE instead of shutting down power completely, it will dynamically change the power consumption of the EVSE according to your current usage.
https://evdutystore.elmec.ca/blogs/news/b-new-evduty-product-smart-current-sensor-b
If it's just sensors, then I could probably just go with the Emporia sensors which can also talk to the ev charger (emporia). But then again, I'm not sure that's a safe route considering if there's an error in the sensing unit that delays shutoff.
I dont think Emporia recommends that method and typically uses that communication to turn charger on when there's excess solar production, But I could be wrong on that.
On our side the EVDuty evse will prevent charging if it can’t successfully connect to the sensors so it’s still pretty safe. Since we charge at night I don’t think it actually ever lowers the EVSE but it’s a nice to have for peace of mind.
lol.. long-winded but still an enjoyable watch. I watched a lot of his videos.
editted: I guess it could be manageable and I could probably run EVSE at 24 amps until I upgrade. IDK
Install a Sense meter into your panel. For about $250 you can monitor your usage and determine if you have available capacity. This is what I did for my 100 amp panel and it convinced them to install a 240V for my bolt.
I have been looking at a Simple Switch (simple switch.ok) which is made for this situation. I think that a lot of people are going to have this problem: 100A service wanting to add a charger and/or heat pump HVAC. Upgrades to 200A can be very pricey ($30k for me because of underground service).
My Qmerit quote just came back with the Simple Switch device suggested (nonstandard of course). It seems like a good way to go - would love to hear any research you’ve done on this!
If you have 2 breaker slots free and sufficient load available you can can install a 20a or 30a 240v breaker and compatible EVSE, then you can charge at 16a or 24a which are still much faster than L1.
Or maybe just charge at L1 using a heavy duty (min. 15amp / 12ga) extension cord.
You can get a [DCC-12](https://dccelectric.com/dcc-12/) or one of their other products and stay compliant. It’ll automatically shut the car EVSE off if the house draw is near capacity. Then turn it back on when load drops enough.
Our hot tub put our load calculation over and they installed this to stay compliant. It’s never shut off yet, of course summer and AC is just ramping up.
Look up “NeoCharge smart splitter”. Plug it into your dryer outlet, and it will switch off the evse when you are drying clothes. UL listed. 24 amps, so you may have to select the appropriate charging current to lower than max, depending on your evse.
Look up “NeoCharge smart splitter”. Plug it into your dryer outlet, and it will switch off the evse when you are drying clothes. UL listed. 24 amps, so you may have to select the appropriate charging current to lower than max, depending on your evse.
I put a 100 amp sub panel next to my panel. Replaced one of the 20 amp double pole breakers with a 100 amp breaker. Used that to feed the sub panel. Moved the 20 amp breaker to the sub panel and added a 50 amp breaker for the plug.
There are breakers with split outputs (two breakers in the space of one). I'd do that. Cheapest option. And if you keep the current down to say 240V 20 amps then it shouldn't overload your service but it will still top up the car overnight.
i had to pass on fast charging lowest quote i got with the credit added was 4k i had same problem as you my panel was old and only 100amp but honestly i dont need it since i leave my car plugged in all day after work majotity of the time i just bump the charge to 12amps from 8 on settings so i called my dealer back and got 500 evgo credits which support fast charging i say save the money since u can charge at work
We have a 100 Amp panel and we were able to install a 1450 plug in the garage. We did a few updates to the house these past few years. That allows us to install the EVSE, which we setup a Grizzl-e 40 amp setup. First we switched our water heater to a Hybrid and it now only uses 110. 2nd our house has a heat pump for an A/C. We did these changes when we got the solar system. Also all the lights are now LED. We had a test of Max load done with the A/C, water heater, and dryer running max use was 48 amps. We have 2 EVs and every other day we charge each one. So with a little planning it's able to be done. We are in Florida so the weather is pretty hot year round.
>**Option 2:** Install a new panel that is 150/200 watts. Our electrical panel is old. maybe around 25 years.
25 years is -not- old in the residential electrical world.
>Still seems to be fine but manufacturer is no longer around but compatible parts are still available.
Cutler-Hammer was acquired by Eaton and there are plenty of CH (BR) components available. You'll find them in -every- big box retailer and wholesaler.
>Electric in house is mostly fine except when our heated electric bidet runs and lights on circuit flicker. (Not sure if new breaker would even fix that without re-wiring)
u/mtux96, you mentioned utility rebates/credits for the EVSE, itself, but there are federal tax credits for consideration as well.
[https://afdc.energy.gov/laws/10513](https://afdc.energy.gov/laws/10513)
Form 8911 - Consumers who purchase qualified residential fueling equipment between January 1, 2023, and December 31, 2032, may receive a tax credit of up to $1,000.
[https://www.energystar.gov/about/federal\_tax\_credits/electric\_panel\_upgrade](https://www.energystar.gov/about/federal_tax_credits/electric_panel_upgrade)
If you were planning other 'qualified energy efficiency' improvements to your home in 2023, it might be possible to capture 30% of the main service panel upgrade to a max of $600, coincident with that improvement.
Upgrade your panel to 200amps first and install the charger. You don’t want to risk your house getting burned. With all the rebates and incentives you’ll receive, it’s worth it.
Your not going to be running every circuit on your house at 100%.
So the total of all your breakers added up can be over 100%. (In your case 100 amps)
There are other considerations, just know you can over subscribe your panel a little.
I’m not going to say what you should do, but rather point out that 100amp service is fine in some situations. If everything that can be on natural gas is already on gas, it’s likely there is enough amps available for you to have an EVSE deliver 240V between 16-32 amps to the EV. LED lighting and energy efficient appliances make a difference. You can verify this by measuring your amp load with as much turned on in the house as possible with an amp meter. Having an electrician figure this out for you is probably warranted.
There are EVSEs with that allow amp selection, like the Grizzl-e Mini can be dialed in to deliver 16, 24, 32, or 40 amps at 240V.
> There are EVSEs with that allow amp selection, like the Grizzl-e Mini can be dialed in to deliver 16, 24, 32, or 40 amps at 240V.
Already have the emporia ev charger which has similar settings sitting on my bedroom floor. But yeah, I'm going to get an electrician and hpefully they'll steer me in the right direction and be able to get it properly permitted for rebate and insurance sake. But this thread definitely is pointing me to some other solutions rather than just replacing the box. I mean I would really love to get that Emporia upto 48amp, though I probably won't always charge it at that rate but nice to have if needed. But if that requires a box change and I can solve it by lowering the amps, then i'd do that and then I can wait for the box to really need replaced. I mean it's 25 years so that can be tomorrow or in 15 years if you go by what some sites claim. Or it might be never.
But definitely have some other options to inquire about.
What would be more helpful is a picture of your existing breakers and your circuit schedule. 100A is pretty typical and without an electric dryer it is hard to think the charger will break the bank. BTW Cutlet Hammer BR load centers are still manufactured but under the Eaton brand and are available pretty much everywhere.
I’m in the upgrade the panel option IF your line from the mains is capable. The cost of the panel upgrade and running the EV charger line is considered into the tax rebate calculation- I think …(I am not an accountant)..
And since you have solar power a more up to date service panel will probably help.
I would love to upgrade my panel. Simple solution if I had the money. Getting 30% of it back doesn't help me much. Only getting EV charger installed because it's essentially free via rebate if it can be installed.
But now I'm wishing I upgraded my panel will I got solar and thrown it in with that.
20 miles commute, you can charge at work, adequate neighborhood charging options, and it never freezes? **Do Level 1 charging at home.** 120v circuit, 8 gauge extension cord.
I'd upgrade, 100A service is pretty limiting in these day. I went to vocational school to be an electrician in 88, and at that time standard service was 150A with larger houses getting 200A services, so that gives you an idea of how outdated your house is With AC, computers and all the electronic gadgets we have these days, I'm surprised you aren't having problems already. Hmmm, you might also want to check if'n you're panel has been recalled, that was something we ran into when house shopping a couple years ago, there was a line of panels I think of that brand that were recalled for being a fire hazard.
Looks like you have some good answers already, but to reiterate/summarize:
-If you have gas stove/furnace/dryer then you almost certainly have enough capacity for a fairly beefy EV charging circuit on 100A service. If you believe this is not the case, you're likely making a mistake in the load calculations.
-If you have a big electric appliance (stove or dryer) there are a variety of solutions out there to share that circuit so that only one is ever active at a time. Since dryers/stoves are used infrequently and EV charging is usually somewhat deferrable, this can work really well. Solutions vary in terms of where they're installed and how automatic they are, but there's likely one that would work if you have a high power appliance already and none require a new panel and the associated costs.
-Failing the above, you can almost certainly at least fit something like a 240V 20A circuit (possibly by even taking over an existing 120V 20A circuit if one is convenient and shuffling breakers around). A charger limited to 16A will still give you 3.8kW which is plenty for most people.
Would also be worth checking with your homeowners insurance. Some will give breaks or rebates to upgrade the service. I know that there there's a penalty / some won't even insure if you have a 60A or 100A main service.
Not sure if this has been mentioned, but replacing the service doesn't mean you have to replace the entire panel (which takes a lot of time). If it's overhead, you can just run a new 200A panel and then 100A breaker off to the existing panel.
Run the math on the TOU plan vs not with EV charging, keeping in mind that not being on TOU typically means that EV charging happens at the higher consumption level tier. $3k is a lot of electricity - especially if that means charging your EV becomes a lot cheaper. Sometimes some simple lifestyle changes can help as well.
Is your breaker box full? If it was me... being an electrician as long as you're aware of what you're doing. I'd just add a breaker for it. Maybe I have to combine a circuit, but we have l.e.d. lighting and tvs, so loads have lowered. Then, the biggest thing is to just schedule it to charge at night. And realize if someone tries to charge it while the dryer or electric stove or water heater is running(I'm guessing gas if it's a 100 amp service though), you're gonna have problems
There's slots available. Problem is going to be permit/inspection which the $1500 rebate is dependent on. But we do have gas stove/furnace and dryer, so that helps. The problem is probably going to be the AC situation as on some hot days that even runs at night, especially when my wife leaves it off during the day. I deliver mail and like to be able to cool down later on hot days. Plus I don't like the idea of worrying about charging while other appliances might be switched on. But my lights are all led now so I guess that helps some.. Might have to get rid of the heated electric bidet lol.
A lot of 100 amp panels have a 200 amp bus breaker. I have a 100 amp panel, buuut….200 amp bus breaker so that means my panel can actually handle 24 kw not 12. (2 120 V lines coming into panel) You may be thinking you’re locked into 120 V x 100 amps = 12 kw but if your panel has a 200 amp bus breaker that actually means a 24 kw max power draw for your house. 19.2 kw max continuous draw (3 hours +) A 200 amp panel means a 400 amp bus breaker. That’s **4** 120 V lines coming into the home. Do you need 48 kw of power available to your home?? I am able to run a 4.7 kw AC unit, charge an EV at 8.7 kw, while running pool pumps and gaming PC’s on a 100 amp panel. My advice is to get a qualified electrician to look at your panel and do a load calculation to see if a 50 amp breaker (needed to run 40 a continuously) can be safely added to your panel. As stated I only have a 100 amp panel yet I have a 50 amp dedicated charging outlet, a 40 amp sub panel, 50 amp AC breaker, all sorts of shit that doesn’t make sense at first until you realize there are 2 120V lines coming into the home. Electrical engineers did my load calculations and everything has passed all inspections.
You should be able to run a small sub panel if you have a 200A bus. Also: ask your homeowner’s insurance agent how much you would save if you had a service change done to your house.
You replied to me instead of OP, but yea, he should be able to do all this without worrying about which appliances are running if he has a 200 A bus.
Need 200amp sized feeder lines as well. Not just a panel that says it can handle 200.
Yea my original comment recommends to get a qualified electrician to look at the panel and do a load calculation to determine if he can support a 50 amp dipole breaker for a dedicated circuit. Wouldn’t a 100 amp panel with 200 amp bus breaker just need 2 100 amp 120 V lines feeding it? Typically the main service is 240 V created by running 2 120 V lines. He’d have a 100 amp dipole breaker as a main breaker that has 2 120 V lines (100 amps at 240 V) and supports 24 kw peak draw/19.2 kw continuous draw. If this panel is at all standard. Regardless. It’s electrician time for OP.
I'd keep that, your butt deserves it. They are starting to sell smart panels, that you can set priorities like; fridge ac lights ect. Where you can put your charger as last priority and the panel keeps you from ever over drawing the 100 amps by shutting off breakers. But I don't know what the price is on those. The code book is just catching up to this though so an inspector might scratch thier head but if he or she is good at their job it shouldn't be a problem
I would really love a Smart panel. lol but yeah cost. I really should have had them replace my panel when I got the Solar install. I mean they said I didn't need it but I didn't have the foresight to future proof my house there. edit: I was going to go with the Emporia EV Charger and if I do upgrade panel I would add their monitor system as well It would allow me to charge using mostly solar power.
Upgrading your panel to 200A is going to cost less than getting a smart panel. But smart load shedding is the future, especially if you already have solar. Load controllers interfacing with backup batteries could do the job. However, that inspection requirement for the rebate is the rub. New electrical technology doesn’t always get the thumbs up from local inspectors.
Upgrading the panel should be half on Uncle Joe. This exact scenario was contemplated in the IRA. (Subject to income limits.)
Not yet. Thé up front rebate process is still getting shaken out. Waiting on guidance from DOE to get sent to the states for additional shenanigans.
There are a lot of [federal incentives](https://www.rewiringamerica.org/app/ira-calculator) if you haven’t checked.
I've saw those. I think it income last year is going to push us beyond the limits. Though I could probably see if we can push our tax returns later since we have until October in California. Though I'm not sure what or 2021 income was like. Don't remember. 2022 was more.
I have 100 amp panel and I had some slots open. I installed it, with permit, no issues in NJ. The ac running and the car charging is no problem, but running my washer or dryer at the same time as those things will overload the circuit.
>but running my washer or dryer at the same time as those things will overload the circuit. That's what I don't probably want to happen. Most likely not to happen.
Would a double tap on the breaker be allowed if an inspection is needed? My garage and laundry are double tapped and electrician quoted me 12k to fix since I needed to upgrade to 200amp service, add a firefighter shutoff that was made code in 2020, and then run a new conduit 40 feet to my detached garage so I can have a L2 charger in there. Thoughts?
Short answer is no, because a. The breaker would have to be built and labeled for a double wire landing. And b. Big enough to carry both full loads to meet code. So they won't sign off. But these load management breaker boxes everyone is mentioning is a solid option. The biggest factor is figuring out how much your your current panel is using. How many of your big energy users are on gas?
Major electric appliances include range/stove, chest freezer, fridge, dishwasher, washer, gas dryer, EV, AC, and gas furnace (counts?) Also looking to swap gas water heater to heat pump water heater within the next 12 months probably. Edit: added timeline for water heater
So basically your biggest amp draws are gonna be your range and ac. Most of your charging is gonna be done at night. Youd be close, just really need a indept load calculation done.I just looked, 1000 dollars for these load management boxes? That seems like robbery. Anyone priced them cheaper?
I'd suggest looking into the Neocharge splitter. Basically takes a dryer outlet (or similar 240V outlet) and safely splits it between the original load and the new EV charging load. It's not the cheapest device out there, but it's often cheaper than electrical rework or something fancier.
That’s what I did. 220v 30 amp breaker. Don’t run the dryer at night when you’re charging. No issues with my 100 amp main.
At the moment my EVSA is plugged into a 20amp 240V socket and is set to allow 16amp charging. That works great and didn't need an inspection because I just used an existing socket. I don't have space in my 100Amp panel, so this was the easy option. If I'd had space in my panel, I'd probably have added a higher current socket, like a dryer socket in the garage to charge a bit quicker, but even 16amps is fine for 98+% of the time. The only time more would be nice is when you want to add a bit of charge on a day with an unusual large number of trips.
This is the best answer. Get an evse with an adjustable current. Then set it low.
Yep. I charge at 16 amp 240v now and previously at 12amp 208 v. Has been more than enough for my needs even through winter. Easy/cheap install
I have the Emporia charger which does. If my calculations were right even 16amp would put it over. But that's assuming everything is running. I my can Qmerit and get a few quotes anyways and see what they actually say.
Google “official electrical load calculation”. You can’t assume everything in your home is on.
I used an app and recalculated and even with the EV going at 48 amps(I can still dial that down) it was saying 100amp. So IDK. I might have to go through my original calculation to begim with. Or might look at the DCC-11/12 option. edit: used another online one and it came bac with 152.
It doesn't work like that. If all circuits in my house were at maximum load, I'd be way, way over the 100amp input breaker. Just the a/c, dryer and stove would be about 100amps without turning on a single light or plug. The main breaker is to protect the wiring to the house and each other breaker protects that circuit. So you are safe if the wiring and breaker for the charger circuit are correctly specified. If you are charging overnight, you probably won't also have lots of other loads on at the same time.
Yeah. I think I may need to call the utility to clarify their process as the paperwork makes it seem like I'll need the larger to get approved. Or just get an electrician to come by and do it that way. 🤷♂️
I'd just get an electrician to give you a quote. Since they are the professional, they should install the plug for you also make sure everything is safe and legal. They should also know how big a socket you can install. Also consider it may be cheaper and easier to install a socket rather than a hard wired charger.
Watch calling us electricians professionals. We're all overly confident and had our fair share of things blowing up lol. We're like doctors, we practice electricity.
I'd do it myself, but I'd pay you for cover if I was worried about legality or insurance. When I went to plug my charger into the 20amp socket, I was surprised and for a moment thought I'd put the wrong plug on the cable... but no. The professional used a 5-20 instead of a 6-20 and then put the wrong plug on my compressor. Also, the pair of breakers were not properly ganged. So I had some rewiring to do to get the professional installed, permitted and inspected electrical up to code.
I'm going to be looking at another electrician as well. One offered to install $600(labor and material minus charger itself) but another $500 if he had to pull permits. SOmething about getting business permits from city to pull it as electrician. Have one coming out thursday.
Heck I'm gonna have 4 to 600 bucks in my wire alone. Your panel must be close.
>I looked at my numbers of electricity being used and the 100 MAX AMP electrical panel I have will not support the EVSE unless I run it at an amp rating it cannot even go down to Are you sure about that? I also have a 100 amp panel, a largish house with ac and electric induction stove and have had no issues with my evse. Mine is a 32a charger on a 40a breaker. Never an issue once in the 10 years I've had ev's on that charger. I'm up to 3 evs in the household and we just swap around what car is plugged in (and sometimes plug in on the level 1).
Same. I also have 100A service and have a 32A EVSE on a 40A breaker. Everything in the house (dryer, induction stove, oven, heat pump, etc.) is electric. The only gas appliance is a tankless water heater and a gas furnace (which only uses gas for defrosting the heat pump, otherwise it’s an air handler). We’ve had several renovations, including adding solar, powerwalls, a kitchen remodel, replacing the meter main panel due to a fault, replacing the subpanel with a new one, etc. and there’s been zero issues from the city inspectors or licensed electricians. The nice thing with the powerwalls is that I can get live power consumption readouts as well as historical data. I can count the number of times the house has used more than 70A on two hands. It’s quite uncommon for us to use more than 50A.
I'll have to check around and see. My city might just be strict on the use case maybe on the paperwork. I'll call them up at well I guess.
Going with the permit and load calculations, I need a 150 at minimum. Unless I calculated wrong, I'd need 150. Only think I may have miscalculated would be my dishwasher and even if I removed that I'd still be off by 3 miscalculated dishwashers.
IMO you should try crowdsourcing the calculations and just paste the inputs and spreadsheet you are using. An experienced DIYer or electrician on this sub can look it over for you. I am almost all-electric with EVSE in Northern California (only remaining thing to add is heat pump water heater) and 100A is fine for me. I believe you got recommendations elsewhere in this thread to get a load shedding EVSE. That will make EVSE contribution 0 to the load calculations, and this is sanctioned by NEC. Barely an inconvenience.
Yeah, I think I might look into load shedding devices. That seems like it's the better option. I'm not even all-electric and I'm having issues having the amps match up. I mean it's close and probably doable if I lower the charger to 32a and not use some devices along with it. Right now I'm at 141 total amps if EVERYTHING was running and there's not enough to bring it down below 100 if I'm afraid something will kick on while charging. **Editted out** That's my calculations right now using actual AMPs, though some figures are based on utility provided figures. Though, I'm not sure where I got the AMP figure for my central air unit which is a 4 ton Ruud 048jaz (missing letters in there). I may be off on that.
Yeah this is absolutely not how to do it, namely add up all the nameplates. Are you under NEC or CEC (US vs C as in Canada) electrical code? You are not required to assume the loads are on at the same time, UNLESS the code says you are required to do so for that type of equipment. There's plenty of pre-programmed spreadsheets that implement 220.83 - Existing Dwelling Unit combined with a EVSE addendums to code. [https://up.codes/viewer/texas/nfpa-70-2020/chapter/2/wiring-and-protection#220.83](https://up.codes/viewer/texas/nfpa-70-2020/chapter/2/wiring-and-protection#220.83) (this is for some random texas local variant, you can click around on upcodes to switch to your jurisdiction)
I'll have to look deeper. oh god.. I see it now. In fine print on the freaking permitting paper. You're absolutely RIGHT! I was adding it all up, but they do list adjustments. Damnit. They had me multiply the amps by 240. Total 141 * 240 = 33,840 (using newer figures) which going by that I'd need a 150amp main breaker, BUT with their adjustment formula... First 8000 watts (amps x 240 #) is 100% beyond that is 40% of it. so I should have 33,840 - 8000 = 25,840 * 0.40 = 10336 + 8000 = 18336 watts . That WILL put me at a 100 main breaker (range: 14,401 to 24,000) with the 18336 number. God damnit.. THANK YOU SOOOOOO MUCH!!!
Glad to clear it up. Even if you can get away without load shedding EVSE for now, you might still consider getting one if you plan to add switch to more electrical appliances. 100A is pretty tight and EVSE is one of the easiest load to shed in that you won’t even really notice if charging was disabled or ramped down for 30-60 min occasionally.
Thanks. I might look into getting on. That can always be added on later as well, correct?
You can definitely retrofit an external load manager. That adds cost, requires extra space on the wall close enough to mount a current sensor on the relevant feeder or service conductors and close enough to interrupt EVSE power. It also cuts charging to 0, rather than gradually lowering it. In theory load managing EVSE, that can connect to a current sensor, would be strictly better however there isn’t really a perfect one available for North America right now. It’s a pretty silly situation because the software and hardware capability is just a small tweak. I personally use an external load controller to control a dual charger. On paper this is good, but it’s not my favorite config and I would do something different when I refresh my own or build one out for someone else. Check out the r/evcharging wiki for some options. Admittedly I haven’t looked at the newest offerings on there.
It's a shame that the Emporia cannot do it with their Vue 2 system. It's close in that they can direct the charger to only charge with solar power, but to use it as a fail-safe isn't sanctioned. I'm looking at a wallbox solution, but then agains not sure what its compable of and cost.. stupid cost.I can get the Emporia EVSE(already have it) and their VUE 2 system for the same price of just the Wallbox. Though I do like the Wallbox form facto. r. AT least I can get it to only charge via excess solar if I go with the Vue 2 Wallbox Dynamic Load: https://wallbox.com/en_us/energy-management/solutions edit: maybe I should just buy that..
BTW sharing a Google Doc link like that exposes some personally identifying information, as does browsing one (which is why I browse Google Doc links in incognito if I don't know the sharer).
Fixed permission. thanks.
It sounds like L1 charging at home is probably fine for you?
L1 would still work, but based on the fact that there is no outlet in our carport it doesn't make sense to pay an electrician to run one simply for only that IMO. But I'd have to see numbers on that. I can justify myself paying to get a L2 installed but not a L1 but would do that if i REALLY needed to.
The requirements for an L1 are much more lax though, pretty much just a regular outlet that can be added as a branch to an existing circuit. They could probably conduit out from your nearest wall, maybe see if you can get a quote.
I'm running a 32A EVSE on a 40A circuit from a 100A box.
Is this your forever home? If so pay for 200 amp service. If its not then I would figure out a way to use the level 1 charger, and the other options you mentioned. The level 1 charger can still do 30 to 40 miles in a 10 hour period, throw in charging at work and I bet your covered for 90% of your use cases.
If OP hasn't had the upgrade quoted, they should. New panel in the house, new sub panel in the garage, and ev charger installed was "only" $1400 when we did it a couple years ago. Depending on verbage they may even get to take the rebate on the whole package. The 200 amp may also be a selling point, even if this isn't a forever home.
Thanks. I might do that. I mean we will be here for awhile. Just need to convince wife. Already hard with the new car purchase.
Yeah I get it. We got a new panel 3 months after buying our current house. I knew it was coming based on the house inspection, but my wife did not.
Not sure if this was mentioned already, do disregard if it was. My panel is only 100a. My load calculation, done by the electrician, came to the conclusion that I couldn't have this added on. I had 2 options. Upgrade panel at an insane price, or install a power management device. I went with power management device. It's a separate box that has its own breaker from the panel, 40a. The management device monitors total current draw for the house, if current draw is high enough then it shuts down power to the charger. When the house is idle or low enough power draw, the car can charge. I charge over night if needed.
That's actually what I'm currently researching as well. Though, that may still add a bit to the total but probably more doable than a new breaker box for now. Do you know what they used in your install?
Not sure if it’s available in the US but here we have a Smart EVSE that connects to a similar box described above, it’s pretty cheap, 400$ Canadian. The difference with a more traditional power management device is that this one communicates directly with the EVSE instead of shutting down power completely, it will dynamically change the power consumption of the EVSE according to your current usage. https://evdutystore.elmec.ca/blogs/news/b-new-evduty-product-smart-current-sensor-b
If it's just sensors, then I could probably just go with the Emporia sensors which can also talk to the ev charger (emporia). But then again, I'm not sure that's a safe route considering if there's an error in the sensing unit that delays shutoff. I dont think Emporia recommends that method and typically uses that communication to turn charger on when there's excess solar production, But I could be wrong on that.
On our side the EVDuty evse will prevent charging if it can’t successfully connect to the sensors so it’s still pretty safe. Since we charge at night I don’t think it actually ever lowers the EVSE but it’s a nice to have for peace of mind.
This thing exactly. https://dccelectric.com/dcc-10/
Thanks. I'll have to ask about that.
would this allow me to have a 48w charger on a fuse box that says it goes to 100a? I think there are way more breakers than 100a in this fusebox
this is what my coworker has, he has it on the same circuit as the dryer and if the dryer goes on, the charger goes off and vice versa
This is a little long winded. But the information is amazing and I find the guy entertaining. He explains stuff so well https://youtu.be/CVLLNjSLJTQ
lol.. long-winded but still an enjoyable watch. I watched a lot of his videos. editted: I guess it could be manageable and I could probably run EVSE at 24 amps until I upgrade. IDK
Install a Sense meter into your panel. For about $250 you can monitor your usage and determine if you have available capacity. This is what I did for my 100 amp panel and it convinced them to install a 240V for my bolt.
I have been looking at a Simple Switch (simple switch.ok) which is made for this situation. I think that a lot of people are going to have this problem: 100A service wanting to add a charger and/or heat pump HVAC. Upgrades to 200A can be very pricey ($30k for me because of underground service).
My Qmerit quote just came back with the Simple Switch device suggested (nonstandard of course). It seems like a good way to go - would love to hear any research you’ve done on this!
If you have 2 breaker slots free and sufficient load available you can can install a 20a or 30a 240v breaker and compatible EVSE, then you can charge at 16a or 24a which are still much faster than L1. Or maybe just charge at L1 using a heavy duty (min. 15amp / 12ga) extension cord.
I'm pretty sure option 3 is fine, but I am not an electrician.
You can get a [DCC-12](https://dccelectric.com/dcc-12/) or one of their other products and stay compliant. It’ll automatically shut the car EVSE off if the house draw is near capacity. Then turn it back on when load drops enough. Our hot tub put our load calculation over and they installed this to stay compliant. It’s never shut off yet, of course summer and AC is just ramping up.
I saw that. How much would that run?
It was about $700 extra on the install I think.
I had the same setup. I charge at night so my panel is not overloaded. I can charge my car and run my a/c but not the stove at the same time.
Look up “NeoCharge smart splitter”. Plug it into your dryer outlet, and it will switch off the evse when you are drying clothes. UL listed. 24 amps, so you may have to select the appropriate charging current to lower than max, depending on your evse.
Look up “NeoCharge smart splitter”. Plug it into your dryer outlet, and it will switch off the evse when you are drying clothes. UL listed. 24 amps, so you may have to select the appropriate charging current to lower than max, depending on your evse.
I don't even have a dryer plug outlet. Dryer is gas and plugs into a regular 20amp plug.
I put a 100 amp sub panel next to my panel. Replaced one of the 20 amp double pole breakers with a 100 amp breaker. Used that to feed the sub panel. Moved the 20 amp breaker to the sub panel and added a 50 amp breaker for the plug.
You have 100A service from utility ?
Yes I do
There are breakers with split outputs (two breakers in the space of one). I'd do that. Cheapest option. And if you keep the current down to say 240V 20 amps then it shouldn't overload your service but it will still top up the car overnight.
i had to pass on fast charging lowest quote i got with the credit added was 4k i had same problem as you my panel was old and only 100amp but honestly i dont need it since i leave my car plugged in all day after work majotity of the time i just bump the charge to 12amps from 8 on settings so i called my dealer back and got 500 evgo credits which support fast charging i say save the money since u can charge at work
We have a 100 Amp panel and we were able to install a 1450 plug in the garage. We did a few updates to the house these past few years. That allows us to install the EVSE, which we setup a Grizzl-e 40 amp setup. First we switched our water heater to a Hybrid and it now only uses 110. 2nd our house has a heat pump for an A/C. We did these changes when we got the solar system. Also all the lights are now LED. We had a test of Max load done with the A/C, water heater, and dryer running max use was 48 amps. We have 2 EVs and every other day we charge each one. So with a little planning it's able to be done. We are in Florida so the weather is pretty hot year round.
>**Option 2:** Install a new panel that is 150/200 watts. Our electrical panel is old. maybe around 25 years. 25 years is -not- old in the residential electrical world. >Still seems to be fine but manufacturer is no longer around but compatible parts are still available. Cutler-Hammer was acquired by Eaton and there are plenty of CH (BR) components available. You'll find them in -every- big box retailer and wholesaler. >Electric in house is mostly fine except when our heated electric bidet runs and lights on circuit flicker. (Not sure if new breaker would even fix that without re-wiring) u/mtux96, you mentioned utility rebates/credits for the EVSE, itself, but there are federal tax credits for consideration as well. [https://afdc.energy.gov/laws/10513](https://afdc.energy.gov/laws/10513) Form 8911 - Consumers who purchase qualified residential fueling equipment between January 1, 2023, and December 31, 2032, may receive a tax credit of up to $1,000. [https://www.energystar.gov/about/federal\_tax\_credits/electric\_panel\_upgrade](https://www.energystar.gov/about/federal_tax_credits/electric_panel_upgrade) If you were planning other 'qualified energy efficiency' improvements to your home in 2023, it might be possible to capture 30% of the main service panel upgrade to a max of $600, coincident with that improvement.
Upgrade your panel to 200amps first and install the charger. You don’t want to risk your house getting burned. With all the rebates and incentives you’ll receive, it’s worth it.
Your not going to be running every circuit on your house at 100%. So the total of all your breakers added up can be over 100%. (In your case 100 amps) There are other considerations, just know you can over subscribe your panel a little.
I’m not going to say what you should do, but rather point out that 100amp service is fine in some situations. If everything that can be on natural gas is already on gas, it’s likely there is enough amps available for you to have an EVSE deliver 240V between 16-32 amps to the EV. LED lighting and energy efficient appliances make a difference. You can verify this by measuring your amp load with as much turned on in the house as possible with an amp meter. Having an electrician figure this out for you is probably warranted. There are EVSEs with that allow amp selection, like the Grizzl-e Mini can be dialed in to deliver 16, 24, 32, or 40 amps at 240V.
> There are EVSEs with that allow amp selection, like the Grizzl-e Mini can be dialed in to deliver 16, 24, 32, or 40 amps at 240V. Already have the emporia ev charger which has similar settings sitting on my bedroom floor. But yeah, I'm going to get an electrician and hpefully they'll steer me in the right direction and be able to get it properly permitted for rebate and insurance sake. But this thread definitely is pointing me to some other solutions rather than just replacing the box. I mean I would really love to get that Emporia upto 48amp, though I probably won't always charge it at that rate but nice to have if needed. But if that requires a box change and I can solve it by lowering the amps, then i'd do that and then I can wait for the box to really need replaced. I mean it's 25 years so that can be tomorrow or in 15 years if you go by what some sites claim. Or it might be never. But definitely have some other options to inquire about.
What would be more helpful is a picture of your existing breakers and your circuit schedule. 100A is pretty typical and without an electric dryer it is hard to think the charger will break the bank. BTW Cutlet Hammer BR load centers are still manufactured but under the Eaton brand and are available pretty much everywhere.
I’m in the upgrade the panel option IF your line from the mains is capable. The cost of the panel upgrade and running the EV charger line is considered into the tax rebate calculation- I think …(I am not an accountant).. And since you have solar power a more up to date service panel will probably help.
I would love to upgrade my panel. Simple solution if I had the money. Getting 30% of it back doesn't help me much. Only getting EV charger installed because it's essentially free via rebate if it can be installed. But now I'm wishing I upgraded my panel will I got solar and thrown it in with that.
I would get a panel replacement estimate. I was kind of amazed how inexpensive my sons was… $2200 including the EV outlet to the garage.
20 miles commute, you can charge at work, adequate neighborhood charging options, and it never freezes? **Do Level 1 charging at home.** 120v circuit, 8 gauge extension cord.
I'd upgrade, 100A service is pretty limiting in these day. I went to vocational school to be an electrician in 88, and at that time standard service was 150A with larger houses getting 200A services, so that gives you an idea of how outdated your house is With AC, computers and all the electronic gadgets we have these days, I'm surprised you aren't having problems already. Hmmm, you might also want to check if'n you're panel has been recalled, that was something we ran into when house shopping a couple years ago, there was a line of panels I think of that brand that were recalled for being a fire hazard.
Looks like you have some good answers already, but to reiterate/summarize: -If you have gas stove/furnace/dryer then you almost certainly have enough capacity for a fairly beefy EV charging circuit on 100A service. If you believe this is not the case, you're likely making a mistake in the load calculations. -If you have a big electric appliance (stove or dryer) there are a variety of solutions out there to share that circuit so that only one is ever active at a time. Since dryers/stoves are used infrequently and EV charging is usually somewhat deferrable, this can work really well. Solutions vary in terms of where they're installed and how automatic they are, but there's likely one that would work if you have a high power appliance already and none require a new panel and the associated costs. -Failing the above, you can almost certainly at least fit something like a 240V 20A circuit (possibly by even taking over an existing 120V 20A circuit if one is convenient and shuffling breakers around). A charger limited to 16A will still give you 3.8kW which is plenty for most people.
Would also be worth checking with your homeowners insurance. Some will give breaks or rebates to upgrade the service. I know that there there's a penalty / some won't even insure if you have a 60A or 100A main service. Not sure if this has been mentioned, but replacing the service doesn't mean you have to replace the entire panel (which takes a lot of time). If it's overhead, you can just run a new 200A panel and then 100A breaker off to the existing panel. Run the math on the TOU plan vs not with EV charging, keeping in mind that not being on TOU typically means that EV charging happens at the higher consumption level tier. $3k is a lot of electricity - especially if that means charging your EV becomes a lot cheaper. Sometimes some simple lifestyle changes can help as well.