Electric Vehicle Chargers and Milage Questions

Hi all, I’m not in the market for an EV this year, next year, in 3 years or even 10 years, but eventually I will be. For fun I’ve been looking at level 2 chargers so in multiple years I know what to buy when I actually need it. What’s the best chargers around in terms of features for efficient charging with solar? It seems like all have wifi and scheduling built in. As with most OEM solutions, the Tesla wall charger doesn’t have the most features, or does it? Are any made in the US? EVbox just moved their US headquarters to my state, and it sounds like they do some manufacturing there as well, but they only have commercial and industrial chargers at the moment. I’ve seen one charger that is also a solar inverter. I just added solar this summer, so I don’t need an inverter, but in the future could add 2 or possibly 3 panels to my small garage roof. How much power equals how many miles in an electric car? That’ll also help me determine how many additional panels I’ll need for our driving needs. Thanks!

Lots of variables in this one - is your main goal to reduce carbon footprint or reduce cost ? A few thoughts:

  • Are you really going to be able to charge during peak solar ?
  • Does your electric company have an EV plan ? Is it TOU ? What is the cost, CO2 breakdown for utility energy at different times of the day.
  • I ask these questions because I have an EV plan for my cars, which has lowest rates between 12 midnight and 3PM. But from a carbon perspective, it’s better to charge from both the grid and solar between 8AM and noon.
  • An efficient EV today takes around 300Wh/mile (Model 3 or Ioniq)
    All-Electric Car Energy Consumption (EPA) Compared – May 2019
  • In a Tesla, the charger is mostly built into the car, so the “charger” has scheduling control and WiFi, because the car includes those. The plugs are really just “wall connectors” with some limit controls (so you don’t set the car to charge at 100A, when the wiring can only handle 50A).
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The problem is the EV J1772 standard.
EVSE is basically an intelligent charging cord that tells the car how much current it can pull.
That is determined by breaker size & cable specs.
At 240 volt the minimum is 6 amp up to 80 amps (afaik)
6 amps @ 240 volt = 1440 watt and as a rule of thumb is about 5 miles/hour of charging (depending on EV, driving style etc)
I use the openevse setup with wifi and during the day I read my smart meter with zigbee (haven’t tried the unofficial sense api yet) how much power I export to the grid and adjust the openevse (with a margin) to how much my EV is allowed to draw from the grid.
Since sense looks at changes in power, it is always confused when I start EV charging.
When I charge at night at a fixed power rate, it is pretty good at getting my charging recognized.
I wish the unofficial api would allow us to send triggers like “start ev charging/ end ev charging” to sense for reference :wink:

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The charging infrastructure as well as equipment and vehicle offerings will likely be drastically different 10 years from now, so any decisions made on current information (even if you add a margin for improvements) are going to be out of date that far in the future. By all means, add more solar to your roof today, but I don’t think it should be based on how you plan to use that energy 10 years from today.


If your EV has a 90kWh battery… From empty to full will take ~90kWh . Im sure you loose some in inverter to grid to charger to the car battery. A “good” EV right now with 100 kWh battery… 300 mile- ish. I would add every panel you can, but 3 panels is not going to produce 100 kWh in a month. If you run out and get a ford lightening, the battery is a 125 kWh and you might get 220 miles. The GMC Hummer EV battery is over 200kWh and might get 350 miles and I think with 4 big guys in it you might have to have a CDL since its 9,100 lbs (curb weight)… Also the MSRP’s of the 1st addition of this thing is $112,595. The money is the greenest part of that thing.

A tesla charger is good for a tesla. Tesla’s have a “lectron tesla” plug… Every EV sold in the US has to have the ability to charge with the “J1772” plug. So when Tesla sells a car they give everyone an adapter to the J1772 plug. You can buy an adapter from the tesla charger to the J1772 plug. I’m not 100% sure put I think that limits the Tesla charger to 40 amp, which isnt probably a big deal unless you got the 72 amp charger or a charger made for a tesla with dual charger (80 amp). Of course that 200kwh Hummer battery would take something like 4 days or so on a 40 amp charger.


I totally agree, and I’m not making any purchasing decision or infrastructure improvements until I’m actually serious about buying a vehicle, especially since that could be a Tesla, or it could be any number of EVs out now or are even yet to be announced. However, I don’t want to get too far behind the curve on the underlying technologies. When HD came out, I was reading all about that until it became mainstream and got to be too much. Same with UHD/4K.

My EV research has already taught me about the various charging connectors and how Tesla used to be isolated, but now includes an adapter to utilize all (most?) charging infrastructure out there, plus their own Superchargers. I know Model 3s, and this probably Ys, come with limited, or no, free Supercharger time.

Yah, unfortunately my garage is 112 years old, tiny, and can barely fit our hybrid sedan. I’ve already made a spreadsheet of vehicles with their physical dimensions so I can see how tight of a fit various vehicles would be. I think I could get 2 more panels to fit on the optimal part of our house’s roof, but again, how much benefit will 5 panels bring? Probably still not enough for an EV. So far, in the roughly two months we’ve had our panels turned on, we break even each week on generation vs usage. I’m hoping that peak summer generation will more than offset the lack of winter generation. Obviously I am missing a ton of data, but that, plus any and all research I can do will help inform a future EV purchase.

Breaking down the battery pack size is a great aspect of power usage to look at. Usage will also be key. As it stands right now, 50 miles a weekday is the math I’ll be working with.

Thanks all!!

This all depends where you live, I live in WV where during the winter I’m getting 2.5 sun hours on a good day (2.5kwh per 1kw of panels ) then 7-8in the summer. Defiantly a big difference for production May here is defiantly the best for me… not running much heat to AC and still getting the good production, I always get credit in May

I like the plug in hybrid right now, because Im like 4 miles from work. So 1 charge I can got to work, store and whatever for 3 days without the engine ever starting. I don’t get in a panic when I see my battery says 2 miles left either. If I need to drive to the beach… no worries! I can see some of these hydrogen cell cars taking over the EV’s overnight though. I also realize that 5-8 years this 14.1 kWh battery is going to be junk.

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