If you Google you will find a few already exist.

 

Hmmm... How exactly it can "step down" or reduce power from ANY EVSE is a bit of a riddle to me. I would imagine they have some sort of dongle or intermediary plug that fits between the J1772 handle male and your car J1772 female, and can send the car "false" EVSE limit information, causing the car to reduce the amperage.

All of this begs the question: How much will it cost? A new 200A service is not cheap, but it has lots of long term benefits -- adds resale value to your home, allows use of more electrical appliances, makes it easier to install solar etc....

If this gizmo costs $100 then, great. But if its $500 or $1000 better just suck it up and upgrade your panel.

 

Emporia EVSE already has Power Smart that allows dynamically balance the EVSE load in real time. It is included in the Pro EVSE price, but Classic EVSE can also be upgraded.

Though I don't think I needed it, I upgraded my Classic EVSE, so it now has built-in EMS (energy management system).

Emporia Level 2 EV Charger with PowerSmart Load Management for NACS Ve

Get all the benefits of an Emporia Level 2 EV Charger without the headache of costly electrical service upgrades. Emporia’s PowerSmart intelligent Load Management solution dynamically adjusts the EV charge rate, allowing the sum of breakers to exceed your panel's service rating, all while...

shop.emporiaenergy.com

 

Emporia EVSE already has Power Smart

Yes, this is nearly the same concept but if your power company subsidizes certain brands or has benefits for load management on certain brands then this might be useful.

 

you will find a few already exist

I haven't seen them like this, but I haven't really been looking.

Why choose Stepwise over other load management solutions?

Unlike traditional load management that simply turns devices on or off, Stepwise uses dynamic load management to intelligently adjust power in real-time. This ensures smooth EV charging and home electrification without disruptions or costly panel upgrades. Plus, our hardware is proudly manufactured in America, delivering reliable, high-quality technology

How exactly it can "step down" or reduce power from ANY EVSE

It reduces power on the incoming circuit. It also works on other appliances.

 

I haven't seen them like this, but I haven't really been looking.





It reduces power on the incoming circuit. It also works on other appliances.

That’s how the Emporia unit works too, it appears. I don’t have their EVSE, but I did recently install the monitoring system in my panel and it’s really neat to see what’s using all the power. (In my case, it was my dehumidifier!)

 

So their general statement about universal compatibility and 'stepping down' the power from any EVSE is misleading. Jumps right out when reviewing the spec sheet. It will not work with all EVSE's in terms of being dynamic - looks like they have to be OCPP compliant (open charge point protocol). Most EVSE's aren't, and clearly non-smart EVSE's are also not. So best you get there is on/off. Maybe they'll partner with non-OCPP vendors (such as they mention Tesla support), but still the text is misleading - describes best case.

Emporia does this today, and you can monitor many more things in your home. Tesla Universal Wall connector can also load manage when coupled with an accessory in the panel box. enPhase charger also. Good to have more players in the field, but definitely not anything magic. Price at $650 is a non-starter vs. Emporia - where you get an EVSE and whole home monitor for that price.

 

I upgraded the main service panel to 200A when we installed our solar last year. It cost $6,000. So, if we did not have it upgraded, the EMS EVSE would have been a major saving.

Mine is normally set on 200A Service with allocated minimum 8A. If the total load approaches to the service rating, it will reduce down to 8A. During normal use, we will almost never approaches 200A service rating. But this EMS will become very handy when we are on battery and solar operation or on a generator without grid. I can reduce the service rating down to lower amp and still be able to use the EVSE at lower adjusted rate within the set max.

 

When installed, the Stepwise Tap is a central junction point between the panel and appliance, monitoring energy usage and controlling the appliance’s energy draw based on real-time feedback. System nameplate ratings are configured during the installation, set to never allow panel usage over 80%.

So I suspect the was this works for resistive loads is that the device steps down the voltage to reduce the energy draw.

Some EVSE and in vehicle chargers will stop charging between 80-90% of expected voltages but others will continue to operate. However, this is true for pool and spa heaters as well. They have set thresholds at which they will shut off to protect the pumps from continuously running.

 

So I suspect the was this works for resistive loads is that the device steps down the voltage to reduce the energy draw.

Some EVSE and in vehicle chargers will stop charging between 80-90% of expected voltages but others will continue to operate. However, this is true for pool and spa heaters as well. They have set thresholds at which they will shut off to protect the pumps from continuously running.

No - this is a simple relay based load management device: on / off as stated on the spec sheet. There is no voltage adjustment at the output - would wreak havoc on any connected device.

 

if this is different than other load managemnt systems then i feel like its answering a question nobody had.

the EVSE is an ideal last priority user, and has built in load reduction (the evse can talk it hteh car to reduce charging rate)., and a battery (duh) to buffer incoming.
so when the AC comes on, or the dryer, or hottub whatever, they slow or pause the car, then restart later. its actually a pretty clever system, ideal peak shaving.
As a process engineer, i tip my hat.

 

if this is different than other load managemnt systems then i feel like its answering a question nobody had.

the EVSE is an ideal last priority user, and has built in load reduction (the evse can talk it hteh car to reduce charging rate)., and a battery (duh) to buffer incoming.
so when the AC comes on, or the dryer, or hottub whatever, they slow or pause the car, then restart later. its actually a pretty clever system, ideal peak shaving.
As a process engineer, i tip my hat.

That’s why the Emporia solution is so elegant. It actually monitors the total load on your main breaker and will automatically adjust the EV down to keep it below whatever you say.

 

My house has 100A services and I have a 40A dumb Grizzl-E EVSE. There's an amperage monitor and a relay that shuts off power to the EVSE if total amps are too high (as hightech-guy describes for non-supported EVSEs). Then 15 minutes or so later it tries again.

The combination of the oven pre-heating and the EVSE charging (plus whatever other small draws) seem to be the only times the relay has needed to come to the rescue.

We managed to keep our Air Conditioning use down to 2 days this year, and I didn't charge those days but I imagine that would be pushing it as well.

 

100A house here.

When I was shopping, two different electricians, including one that was referred by my utility through a program specifically for installing EV charging and reimbursing me for it, told me there was no problem installing a 60A circuit for my EVSE, without any sort of load management or de-rating.

I have electric A/C, oven, and dryer. They each told me (paraphrasing) "just don't cook AND dry AND cool AND run the dishwasher AND charge at the same time." Maybe it's worth noting that this is a smallish (1700sqft) townhouse with two shared walls, natural gas heating, and a single A/C unit, but I'm in a warm climate and the A/C runs a fair bit, though less so at night.

So I set my EVSE (Emporia) to 32A and 11pm to 7am (since apparently the scheduler on the Equinox is ... uhhh, something 🤷‍♂️) and haven't worried about it since. And not once have those 8 hours been insufficient to fully charge. Usually it's done in under 3. I didn't have to set it to 32A, but it's for the 0.5% of the time that the laundry runs late.

I'm on the side of Mr. Technology Connections* over on YouTube. That is, don't let me stop you from installing load balancing or a service upgrade, but a lot of folks with 100A service would be fine without. (If you have electric heating, and/or a truly awful commute, and/or a bigger EV getting under 2mi/kWh, and/or two EVs needing to charge every day, I don't mean you.)

In my case I only went with 60A EVSE wiring because my utility paid for it; if it were my own money I probably would have opted for 40A or even less. Typical daily mileage in my household is in the 30s. Days over 100 miles are exceedingly rare. Consecutive days over 100 miles have never happened except on road trips.

Maybe one day I'll retrofit a Vue system. I do think it's a neat product. I'm skeptical that it'll do much for me though.

All that said - standard disclaimers. I'm not an electrician. I listened to and followed the advice of my electrician, and so should you.

But that includes maybe doing some math beforehand to see what kind of charging power fits your lifestyle 99% of the time (it's probably less than you think!), and asking your electrician if they can safely install that with your existing service, rather than the standard 60A.

 

100A house here.

When I was shopping, two different electricians, including one that was referred by my utility through a program specifically for installing EV charging and reimbursing me for it, told me there was no problem installing a 60A circuit for my EVSE, without any sort of load management or de-rating.

I have electric A/C, oven, and dryer. They each told me (paraphrasing) "just don't cook AND dry AND cool AND run the dishwasher AND charge at the same time." Maybe it's worth noting that this is a smallish (1700sqft) townhouse with two shared walls, natural gas heating, and a single A/C unit, but I'm in a warm climate and the A/C runs a fair bit, though less so at night.

So I set my EVSE (Emporia) to 32A and 11pm to 7am (since apparently the scheduler on the Equinox is ... uhhh, something 🤷‍♂️) and haven't worried about it since. And not once have those 8 hours been insufficient to fully charge. Usually it's done in under 3. I didn't have to set it to 32A, but it's for the 0.5% of the time that the laundry runs late.

I'm on the side of Mr. Technology Connections* over on YouTube. That is, don't let me stop you from installing load balancing or a service upgrade, but a lot of folks with 100A service would be fine without. (If you have electric heating, and/or a truly awful commute, and/or a bigger EV getting under 2mi/kWh, and/or two EVs needing to charge every day, I don't mean you.)

In my case I only went with 60A EVSE wiring because my utility paid for it; if it were my own money I probably would have opted for 40A or even less. Typical daily mileage in my household is in the 30s. Days over 100 miles are exceedingly rare. Consecutive days over 100 miles have never happened except on road trips.

Maybe one day I'll retrofit a Vue system. I do think it's a neat product. I'm skeptical that it'll do much for me though.

All that said - standard disclaimers. I'm not an electrician. I listened to and followed the advice of my electrician, and so should you.

But that includes maybe doing some math beforehand to see what kind of charging power fits your lifestyle 99% of the time (it's probably less than you think!), and asking your electrician if they can safely install that with your existing service, rather than the standard 60A.

I agree your setup works in practice. In actuality, it is likely a code violation for failing most any load calculation - given your limited 100A service, A/C, oven, and dryer plus EV charging. Sounds like your electrician didn't perform this basic check.

Where the load management comes in is that it enforces compliance, instead of counting on you always doing the right thing yourself with your loads. There is nothing physically stopping you from running your AC/oven/dryer at the same time, and having your EV charge. With load management, it would scale back the power to the EV during this - automatically and without any action on your part. Yes, you can manage yourself, but if you don't - you'll be running at or over capacity if another person isn't as vigilant.

In your case as you already have the Emporia charger, I'd highly recommend adding the Vue. You get lots of good data, and you'll have load management.

 

We are 150 amp, all electric house, and was still able to add a 50 amp circuit for EV charging. We did a load analysis (as specified in the NEC), and it was pretty straightforward. I later added an Emporia Vue 3 to monitor things and I’ve never even seen us get close to 100 amps…

 

Take a look at the Youtube Channel "State of Charge", It is focused on EV chargers and EVs, including the infamous NOX.
They have discussed this type of charger in some detail. They do work, they appear to be cost effective, and there are several options, depending on where you live. And when they cut back power, they do it by modulating the EVSE (charger). We have a chargepoint flex which can be set to charge our NOX at various reduced rates. I have ours dialed down from 48 to 20 amps, for example.