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40 mi commute, office charger debate

What type of charger would you install at the office for a 80 mi total commute? (8-9hr day)

  • NEMA 14-50

    Votes: 28 31.1%
  • Tesla wall connector

    Votes: 40 44.4%
  • 110 outlet

    Votes: 6 6.7%
  • No charger

    Votes: 16 17.8%

  • Total voters
    90
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Most cheaper ($500ish and below) chargers use plugs (14-50 or 6-50).

I would just get a 14-50 connection and use the mobile charger. No need to spend money on a separate wall charger.
I'm not leaving my MC plugged into an outlet in a parking lot unless it's protected from the weather and I'm the only one who has access to said lot. What's going to prevent someone from stealing the thing when it's not locked to the car?
 
True. This makes my cost at home $0.15
If you are going to commute 4 or 5 times per week, plan on staying with your current job for at least the next 2 years, it makes sense to install a charging station at your workplace since your employer will be paying for the electricity. There may be credits/rebates from the local utility that you employer could receive for installing the charging station (would probably have to be a Level 2 charging station such as Chargepoint with a J1772 connector. You can charge the Tesla Model Y with the Tesla SAE J1772 adapter that comes with the Tesla vehicle (I use the adapter every time I charge, except for Supercharging.)
 
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If you are going to commute 4 or 5 times per week, plan on staying with your current job for at least the next 2 years, it makes sense to install a charging station at your workplace since your employer will be paying for the electricity. There may be credits/rebates from the local utility that you employer could receive for installing the charging station (would probably have to be a Level 2 charging station such as Chargepoint with a J1772 connector. You can charge the Tesla Model Y with the Tesla SAE J1772 adapter that comes with the Tesla vehicle (I use the adapter every time I charge, except for Supercharging.)
Payback period would be less than 18 months, assuming 15¢/kWh and 11.2 kWh/day (40 miles @ 279 Wh/mi). That's $1.674/day, or 239 workdays. Plus it cuts your average depth of discharge in half and reduces battery degradation. Now there are ~250 workdays in a year but if we assume you're on vacation or otherwise not at the office for 15-20 of those days, payback time would be just slightly more than a year (WC costs $400).
 
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Payback period would be less than 18 months, assuming 15¢/kWh and 11.2 kWh/day (40 miles @ 279 Wh/mi). That's $1.674/day, or 239 workdays. Plus it cuts your average depth of discharge in half and reduces battery degradation. Now there are ~250 workdays in a year but if we assume you're on vacation or otherwise not at the office for 15-20 of those days, payback time would be just slightly more than a year (WC costs $400).
I would only charge at work during the week, depth of discharge aside, and only charge at home on the weekend as needed for twice the savings.
 
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Love the way the conversion has evolved you guys are great.

Curve ball. No rebates in my area and I’ll only be at this office 2-3 times a week. But I plan to buy into the building in the next 5 years. It’s currently owned by two physicians that are retiring in the next few years. I’m hoping to take over the practice/building at that time.

Aside from cost, which is of course a factor. I am interested in avoiding battery degradation as I hope to have the car for a while as a commuter.
 
If truly just for yourself, you need about 3kw of power to meet that need, though you might want a bit more for your other driving. At first blush, more is better -- though a 6kw circuit with any 30 amp EVSE will be quite a bit more than enough. The simplest and lowest cost would be the Tesla Mobile connector in a permanent mount, which would cost only $200 for the EVSE and provide up to 32 amps. You could also pay $400 for the Wall Connector (which is also not out of stock) with some additional mounting and wiring costs. These are the cheapest EVSEs out there, oddly, and of course come with a Tesla plug -- if they are only for you, they are the choice.

If you want the lowest cost they could put in just a 14-50 and you could bring your own Tesla mobile connector that you already have with the 14-50 plug. They could install any plug (such as a 30 amp or even 240v-15a) and it would do you fine -- that is cheaper to install. In fact, if there is an existing dedicated 120v15a plug it can often be rewired to be a 240v15a, which is by far the cheapest thing to do -- no new wire, just new breaker and plug.

The question is actually more interesting if you are talking about wiring many stations for many drivers in a parking lot. The majority of them can get by with 120v15a or 120v20a. This is bare coverage, so why would you do it? It's much cheaper. If you want to charge 20 cars, it is far better to have 20 stalls at 2-3kw than 8 stalls at 7kw. In the latter case, people have to do a dance every day swapping out cars.

So it would be great to do 20 stalls at 7kw but that costs a lot more.

Ideal might be to put in 2-3 stalls at 7kw and the rest at 3kw. Those few people who need more than 24kwh (Just under 100 miles/day) use the 7kw stall, the rest do fine at the lower speed, and you get a lot more stalls for your money -- no moving cars around.
 
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If truly just for yourself, you need about 3kw of power to meet that need, though you might want a bit more for your other driving. At first blush, more is better -- though a 6kw circuit with any 30 amp EVSE will be quite a bit more than enough. The simplest and lowest cost would be the Tesla Mobile connector in a permanent mount, which would cost only $200 for the EVSE and provide up to 32 amps. You could also pay $400 for the Wall Connector (which is also not out of stock) with some additional mounting and wiring costs. These are the cheapest EVSEs out there, oddly, and of course come with a Tesla plug -- if they are only for you, they are the choice.

If you want the lowest cost they could put in just a 14-50 and you could bring your own Tesla mobile connector that you already have with the 14-50 plug. They could install any plug (such as a 30 amp or even 240v-15a) and it would do you fine -- that is cheaper to install. In fact, if there is an existing dedicated 120v15a plug it can often be rewired to be a 240v15a, which is by far the cheapest thing to do -- no new wire, just new breaker and plug.

The question is actually more interesting if you are talking about wiring many stations for many drivers in a parking lot. The majority of them can get by with 120v15a or 120v20a. This is bare coverage, so why would you do it? It's much cheaper. If you want to charge 20 cars, it is far better to have 20 stalls at 2-3kw than 8 stalls at 7kw. In the latter case, people have to do a dance every day swapping out cars.

So it would be great to do 20 stalls at 7kw but that costs a lot more.

Ideal might be to put in 2-3 stalls at 7kw and the rest at 3kw. Those few people who need more than 24kwh (Just under 100 miles/day) use the 7kw stall, the rest do fine at the lower speed, and you get a lot more stalls for your money -- no moving cars around.
If you actually care about how much your employer is paying for the electricity, then you should put in the maximum number of amps you can. Going forward, the "super off peak" rates are likely to be around noon time, like probably 10am-2pm, due to higher and higher solar generation.
 
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Love the way the conversion has evolved you guys are great.

Curve ball. No rebates in my area and I’ll only be at this office 2-3 times a week. But I plan to buy into the building in the next 5 years. It’s currently owned by two physicians that are retiring in the next few years. I’m hoping to take over the practice/building at that time.

Aside from cost, which is of course a factor. I am interested in avoiding battery degradation as I hope to have the car for a while as a commuter.
Most of the cost of installing the charging circuit will be for the electrician's time, labor. The difference in additional cost for installing a 60 amp circuit versus a 40 or 50 amp circuit will be minimal. Keep in mind that in most places in the US commercial buildings are wired using 3-phase commercial power. You would be able to charge at 200V to 208V but not 240V. 240V is for single phase power used in homes. For a given amperage the power would be less. I.e. 240V X 40A = 9.6kW; 200V X 40A = 8kW (16.7% less.) Never mind that I never see more than 200V when charging this way, at 208V it would be 13.3% less than if you were charging at 240V.) I would ask for a 60 amp circuit but a 50 amp, 40 amp or even 30 amp circuit would work well.
 
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If you actually care about how much your employer is paying for the electricity, then you should put in the maximum number of amps you can. Going forward, the "super off peak" rates are likely to be around noon time, like probably 10am-2pm, due to higher and higher solar generation.
Yes, the peak for office charging will be 9am to 3pm. So you want to fill the average car in that period. Most cars use about 10kwh a day. Some use more. So you want a mix. I mean hey, if you have the budget for it, put in as much as you can for every car. But if you have only a limited budget, better to put in charging for every car than have faster charging for fewer cars. Well, until the cars can move themselves around and plug themselves in, then you actually want to reverse that and have smaller, faster chargers -- within limits so as not to degrade batteries of course.

Which does create a conundrum because both a solar surplus in the morning, and cars that can move themselves in parking lots are both coming, but harder to say exactly when.

On the other hand, today, only a few employees need charging at work. In 2040 maybe all of them need it. So you start with slow charging for every car (but that's only a few percent of the cars) and upgrade over time to different configuration. And a different plug than either Tesla or CCS or J1772 as you want one designed so the car can plug itself in, with the car doing all the robotics.
 
putting aside the pay back period, having this L2 at work removes situations where you might come in on a low charge and need to make a 'gas station stop' on the way home. That's worth getting.

For the company's benefit, the J connector would be more suitable, but if you're paying for this unit, get the one that fits and can restrict use. When a second Tesla user at the company wants to join, he or she can pay 50% of your cost. When the 3rd comes, that person pays 1/6th to each of you. I think you could go as far as 4 users without too much trouble sharing, if you're all part of the same company at the site. A half day does a substantial charge and a 2 hour routine makes up for the daily commute. Rather than plan to charge every day, I'd likely do every other.

So site the charger so that it can reach up to 4 (or 3 if you want to hold the line). When there are more users, deploy the next one. Maybe consider that in the siting choice for the first one.
 
I also vote for getting an J1772 EVSE installed instead so none of the provided choices.

I wouldn't get the cheapest one esp. random crap on Amazon. Get name brand (NOT a no-name) decent UL-listed or equivalent one.

I've posted many reasons why not to before but I mentioned some names at Charge Port Meltdown which was a reply to MUSTART CHARGERS DAMAGING CARS.
Re: Mustart, via Mustart brand -- any experience? Any reason not to get..., TIL of this pretty damning report on that brand at https://www.macheforum.com/site/att..._iwc_-_evse_safety_analysis-et-1-1-pdf.51197/.

It's yet another reason to stay away from no-name random EVSEs on places like Amazon.
 
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