EV Charger Models

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Greg H

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Durham, NC, USA
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Electrician
I have had a few customers reach out to me recently who have purchased or plan to purchase an electric car and want to get a level 2 charger installed in their home. One question most of them ask is what brand or model of charger I recommend. I've been telling that they should buy a charger that has a capacity close to the capacity of their vehicles battery charger and that is rated for the environment (so, NEMA 4 if it is going outdoors). Beyond that I have just been suggesting a decently established brand with a good warranty. I also had a car salesman connection of mine ask me the same question in an email where he also said that "we have seen some issues with higher amperage shorting out the cars chargers input because of temperature sensors reading high levels." He's not an electrician so when he says "shorting out" I think he just means overloading, and whatever he is talking about might be a failure of the cars onboard charger not of the level 2 EVSE. My instinct is that sizing the level 2 charger below the capacity of the vehicles onboard charger should mitigate the risk of the level 2 charger damaging the onboard charger (even if a sensor or other control mechanism fails, the level 2 charger is literally incapable of supplying enough current to overload it), which may explain why I have not heard of that happening with any charger I have installed, at least not yet, though I havent really installed all that many yet either. Still, thought it would be worth asking if anyone here might have had any good (or more importantly bad) experiences with any particular charger brands or models. Thanks
 
Most modern EVs are capable of charging at 48A. There are a couple of models being deprecated (Chevy Bolt, Hyundai Kona, for example) that are less.

Given how the J1772 protocol works, the car controls the charge rate, not the EVSE. The EVSE basically tells the car what it can supply, and the charger in the car does the rest. The EVSE cannot force the car to take more than it can handle. If an overcurrent condition happens, it’s because of the car, not the EVSE, so undersizing the EVSE is not a remedy.

I’ve never heard of a case of a level 2 system failure that verified cause of failure was the charge rate of either component being exceeded.

I own 2 EVs and my EVSEs are Ford-branded made by Webasto. I haven’t had any issues with them, but a lot of people are having issues with the plug-in mobile Charger.

Brands that seem to have a good reputation include ChargePoint and Emporia.

Not as good include JuiceBox (made by Enelex) and Grizzl-E. My daughter has a JuiceBox and it’s been replaced twice. They’ve introduced a couple software changes in the past year that caused issues, as well. The really bad ones are the non-UL listed ones people buy off Amazon.

The main failure points seem to be the connections. There is a thread on here about failed 14-50 receptacles. There have been some reports of failures at the J1772 connection at the car.

If installing an EVSE rated over 32A, I’d recommend one that allows hard-wiring to eliminate the receptacle connection.
 
Not dismissing any advice above, but...

These things are really pretty simple. A bit of electronics that tell the car how much current it can draw, a relatively high-amp contactor, and not much else besides the cable and connector which are probably the bulk of the real cost. Pick any company that's been selling them for 5+ years and I don't think you can go really wrong.

So by all means read reviews if you want to optimize on small details, but don't lose too much sleep. In the end, it's probably more about price and availability among brands with a reputation.
 
retirede said:
Most modern EVs are capable of charging at 48A. There are a couple of models being deprecated (Chevy Bolt, Hyundai Kona, for example) that are less.

Given how the J1772 protocol works, the car controls the charge rate, not the EVSE. The EVSE basically tells the car what it can supply, and the charger in the car does the rest. The EVSE cannot force the car to take more than it can handle. If an overcurrent condition happens, it’s because of the car, not the EVSE, so undersizing the EVSE is not a remedy.

I’ve never heard of a case of a level 2 system failure that verified cause of failure was the charge rate of either component being exceeded.

I own 2 EVs and my EVSEs are Ford-branded made by Webasto. I haven’t had any issues with them, but a lot of people are having issues with the plug-in mobile Charger.

Brands that seem to have a good reputation include ChargePoint and Emporia.

Not as good include JuiceBox (made by Enelex) and Grizzl-E. My daughter has a JuiceBox and it’s been replaced twice. They’ve introduced a couple software changes in the past year that caused issues, as well. The really bad ones are the non-UL listed ones people buy off Amazon.

The main failure points seem to be the connections. There is a thread on here about failed 14-50 receptacles. There have been some reports of failures at the J1772 connection at the car.

If installing an EVSE rated over 32A, I’d recommend one that allows hard-wiring to eliminate the receptacle connection.
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Good to know about the Juicebox, I just installed one for a doctor for his Audi. I will have to let him know to keep an eye on it. He has living quarters above the garage, and around here, they don’t build fire rated structures.
 
hillbilly1 said:
Good to know about the Juicebox, I just installed one for a doctor for his Audi. I will have to let him know to keep an eye on it. He has living quarters above the garage, and around here, they don’t build fire rated structures.
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New IRC needs a heat detector interconnected to 120v smoke alarms and CO2 alarms. I am a fan of the idea to charge in a detached building or outdoors because of this. It doesn't need to be even now but who knows what kind of recall issue will come up it'd be better to mitigate any losses to your property. I wouldn't want to store 100 gallons of gasoline under a bedroom either but people do all the time with 5/8drywall and 3/4 osb being all that's separating it.
 
letgomywago said:
New IRC needs a heat detector interconnected to 120v smoke alarms and CO2 alarms. I am a fan of the idea to charge in a detached building or outdoors because of this. It doesn't need to be even now but who knows what kind of recall issue will come up it'd be better to mitigate any losses to your property. I wouldn't want to store 100 gallons of gasoline under a bedroom either but people do all the time with 5/8drywall and 3/4 osb being all that's separating it.
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Which IRC are you referring to? 2024?
 
letgomywago said:
New IRC needs a heat detector interconnected to 120v smoke alarms and CO2 alarms. I am a fan of the idea to charge in a detached building or outdoors because of this. It doesn't need to be even now but who knows what kind of recall issue will come up it'd be better to mitigate any losses to your property. I wouldn't want to store 100 gallons of gasoline under a bedroom either but people do all the time with 5/8drywall and 3/4 osb being all that's separating it.
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That’s one thing I looked for in the doctor’s garage, which he did have. I was going to suggest it if he didn’t. He did have a large rack of batteries in his basement as storage for his solar panels. He did have a smoke detector in that room, but open wood stud walls and ceiling. Batteries sitting on wood shelves too.
 
There is a member here that does primarily EV chargers that could offer some advice…. Idk how to tag but his username is senoirbubbles


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letgomywago said:
Smoke alarms are the only time I ever really talk to the building inspector and since adoption of the 2018 this has been a required not on building permits in my county and city.
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The only requirement for fire detection in a garage is if there's an ESS installed in it on the 2021 IRC.

There's no requirement (yet) for fire detection for EVs but it's a great idea to have it
 
hillbilly1 said:
Good to know about the Juicebox, I just installed one for a doctor for his Audi. I will have to let him know to keep an eye on it. He has living quarters above the garage, and around here, they don’t build fire rated structures.
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I don’t think they are necessarily a fire hazard. My daughter’s just quit charging. The problems with their app are just a PIA, again, not hazardous.
 
Here are several thoughts that a working electrician might want to have ready and available to potential customers. These are all from personal experience (I own 1 Chevy Bolt and have another on order).

You definitely want to know about - or make your customer aware of - rebates (state and federal). Both on the EVSE purchase price + install as well as TOU discounts from a local POCO. Some of them are substantial and who does not like to be told about free money.

For example - I purchased a Chargepoint HomeFlex EVSE for ~ $740. If that sounds crazy expensive, you'd be correct. But the state of MD gave me a 40% rebate (mailed me a check) off the purchase price. I could have received the same 40% discount off any installations costs, but I wired it myself (don't get mad, you'd likely approve of my mad EMT bending skills!).

In addition to the local State rebate - I got a 30% federal tax credit on the tax return I just recently filed (not a deduction - a full tax credit) using Form 8911 (Alternative Fuel Vehicle Refueling Property Credit). So in the end the total discount was 70% off the purchase price. That's a substantial price cut.

The reason I selected such an expensive EVSE was that in my state, BGE offers a discounted price for any car charging if you choose their EV TOU plan. This does NOT involve another meter, or anything other than tracking the car charging kW hours. They do this by using only "smart" internet connected EVSEs that they can connect to to get your monthly usage and time data. The discounted hours change slightly from summer to winter, and the discount is pretty reasonable (~3.5 cents per kWH). If you choose to charge outside those hours you will pay slightly more - but it's stupid easy to setup charging sessions to start automatically when the cheap rates begin. Right now, using the "winter" schedule, I just plug in when I get home and the EVSE starts the session at 9PM all by itself. I don't drive crazy far for work and I get a rebate of $8 to $10 every month. Not a lot, but it adds up.

So if your local POCO offers a discounted rate, especially one w/o a separate meter or additional monthly charges, they will likely have a short list of smart EVSEs to choose from. Those are good details to know about.

Incidentally, BGE will allow a Tesla driver to sign up for the TOU discount regardless of what EVSE they use. This is because they actually get the charging data from the car itself, and not the EVSE. You obviously have to agree to that when you sign up. If you are scared of big brother knowing how many kWHs you use every month, then these discounts are not for you. Me, I could care less. But check w/ your local POCO for the specifics of any discounted EV charging plans they might have.

If you don't need (or want) any rebates or discounts, then a good basic EVSE should set you back ~$300 to $400. I think. BTW... most cars come with one, or at least used to, so your customer might not even need to purchase one. Beware of crazy cheap units you might see on Amazon, many are not UL listed and you will definitely get what you paid for. Mustart, according to the interwebs, can be a problematic brand. As mentioned above - good names would include Chargepoint, ClipperCreek, Webasto, Siemens, Emporia (sp?) I also favor an EVSE that has an adjustable charging rate - as compared to a single fixed rate.

Lastly, be ready to talk to a customer about reasonable charging rates (amps, not dollars). Just because you can charge at 32, 40 or 48 amps does not mean you have to. Me personally, I have dialed my EVSE back to 24A, and the that "fills" back up my little 40 mile commute in ~ 2 hours. Yes, it's might be nice to charge faster a handful of times per year, but I don't care about those exception cases. And if I really needed to, I can dial up the rate. 24A (at 240VAC), to me at least, is a good sweet spot of a decent amount of current for a reasonable time. I feel like really fast charging rates of 40A (on a 50A circuit) or 48A (on a hardwired 60A) are a bit like instant hot water heaters. It might be right for a few people, but everybody does not need one. Most times, a car is going to sit in the driveway or garage all night, so who cares if it takes 2 or 4 or 6 hours to recover your daily charge. Just because you can charge it back up in 1 hour does not mean you should. Most people want bigger and better... and I get that. But not everybody drives 200+ miles a day - my daily commute of 40 miles round trip is very close to a national average I am sure. And it's good to be ready to offer customers all available options and look smart at the same time. Sell them a 50A circuit with a good quality 14-50 receptacle (which is what I installed in my own garage) so they are ready for most options. But let them know they can charge at something less than Full Beans maybe. And explain why that's OK (less VD, things running just a little cooler, etc).

Sorry for all the words!!
 
MD Automation said:
And explain why that's OK (less VD, things running just a little cooler, etc).
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On that last point, just from an efficiency point of view, running the EV's internal charger may have a fixed or fairly fixed overhead (running cooling fans and radiator pumps, for example). In which case a higher charge rate could be more efficient overall, despite the larger I2R losses.

So slower is not necessarily more efficient electrically. But I don't have specific data, and it would vary by vehicle.

Cheers, Wayne
 
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