I am making a 40 mi commute to work and 40 mi's back each day. I'm set to accept delivery of a MYP in about 2-weeks. I already have a Tesla Wall connector installed in my garage and plan to plug in every night. My office is willing to put in a plug outside for me to charge while at work (~8-9 hr). What type of charger would you install, if any?
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40 mi commute, office charger debate
- Thread starter LibertyEV
- Start date
Is it supposed to be just for you? If so, a Tesla Wall Connector. It can be locked down to only charge certain cars.
I think the answer is the same even if not. I wouldn't want to be screwing with the UMC every day, nor leaving it outside in the rain.
Perhaps adding another option for a fixed-in-place J1772 charger would be wise. I'd still pick the HPWC because its cheaper than most/all J1772 chargers.
I think the answer is the same even if not. I wouldn't want to be screwing with the UMC every day, nor leaving it outside in the rain.
Perhaps adding another option for a fixed-in-place J1772 charger would be wise. I'd still pick the HPWC because its cheaper than most/all J1772 chargers.
ATPMSD
Active Member
80 miles willl require aboiut 20 kW / day (at 250 wH/mi). Assuing you are on charge for 8-full hours you need 2.5 kW /; hour
NEMA 14-50 will give you about 7 kW / hour (32 amp limit on mobile connector)
Wall connector will give you about 10 kW / hour (assuming 60 amp circuit), or about 8.5 kW / hour on a 50 amp circuit
110 oulet on a 20 amp circuit will give you about 1.5 kW /hour
Assuming 90% efficieny for 240v and 80% for 120v. Going with the wall connetor is a Tela only solution.
NEMA 14-50 will give you about 7 kW / hour (32 amp limit on mobile connector)
Wall connector will give you about 10 kW / hour (assuming 60 amp circuit), or about 8.5 kW / hour on a 50 amp circuit
110 oulet on a 20 amp circuit will give you about 1.5 kW /hour
Assuming 90% efficieny for 240v and 80% for 120v. Going with the wall connetor is a Tela only solution.
ATPMSD
Active Member
Only real option is the Wall Connector, none of the others is subitable for outside.
If your workplace is willing to install a charging station for your Tesla vehicle what about other employees who may drive non-Tesla electric and plug-in hybrid vehicles? In my experience the employer or closeby parking structure has installed public Level 2 charging stations. These have the standard J1772 charging connector. The majority of these public charging stations enable charging at 200V to 208V (commercial power) and 30 amps (sometimes 40 amps) for a 6kW to 8kW charging rate.
To charge the Tesla vehicle using a charging station with a J1772 connector you attach the Tesla SAE J1772 adapter that comes with the Tesla vehicle (additional Tesla J1772 adapters currently cost $50 from the Tesla.com online store.) Although the Tesla Gen2 Mobile Connector kit is no longer included when you purchase a Tesla vehicle the Tesla.com online store site states "This product (Tesla SAE J1772 Charging Adapter) comes standard with purchase of any Tesla vehicle."
The Tesla SAE J1772 charging adapter comes with every new Tesla vehicle sold in North America. The Tesla SAE J1772 charging adapter is arguably at least as useful a charging accessory as the Mobile Connector.
Tesla SAE J1772 Charging Adapter
To charge the Tesla vehicle using a charging station with a J1772 connector you attach the Tesla SAE J1772 adapter that comes with the Tesla vehicle (additional Tesla J1772 adapters currently cost $50 from the Tesla.com online store.) Although the Tesla Gen2 Mobile Connector kit is no longer included when you purchase a Tesla vehicle the Tesla.com online store site states "This product (Tesla SAE J1772 Charging Adapter) comes standard with purchase of any Tesla vehicle."
The Tesla SAE J1772 charging adapter comes with every new Tesla vehicle sold in North America. The Tesla SAE J1772 charging adapter is arguably at least as useful a charging accessory as the Mobile Connector.
Tesla SAE J1772 Charging Adapter
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The wrong units on this are driving me a little bonkers. kW is already a per time unit. It is energy per hour, so you wouldn't say energy per hour per hour.
csrpenfab
Member
With an 80 mile round trip, I'd just charge at home! Now if you office is going to let you charge for free, then I'd say Tesla fast charger. That way you're not having to compete with any non-Tesla owners! I have the Tesla wall connector at home, I charge to 80% and plug in maybe 2x a week as needed. My daily commute is about 30 miles R/T.
ATPMSD
Active Member
Technially correct of course, 7 kW is a unit of time but a lot of people miss that. So while 7 kW / hour is redundant, it gets the point accross to the not yet savvy.
What really kills me is 24/7/365!!!
Not entirely correct. kW is a measure of power, specifically a rate of energy transfer, and its everyday expression usage does not typically denote its time component specifically. The watt is the SI unit for power, FYI.Technially correct of course, 7 kW is a unit of time but a lot of people miss that. So while 7 kW / hour is redundant, it gets the point accross to the not yet savvy.
On the other hand, kWh is a measure of energy, expressed in a irrationally bad way, and is not an SI unit. Its a measure of power specifically expressed in the form of energy over an hour of time (obviously), rather than a simple capacity measurement, which would (and should) be expressed as joules. The joule is the SI unit for energy.
That's not redundant. It is something different and not correct.
It's like this. The unit of speed is in meters per second. The unit for the acceleration factor for gravity is in how fast that speed is changing per time. That unit is meters per second per second.
I get why people don't want to use joules, though, because they're so tiny. A kWh is 3,600,000 joules. It would break people's minds to see billions and trillions on their electric bills.
ATPMSD
Active Member
While I am sure you are correct let us not further confuse people!
Right or wrong in the EV world the term kW is generally accepted to be the amount of energy delivered over the course of one-hour while kWh refers to battery capacity. If you wish to correct this everytime it is posted you will have a new full time job. I wish you well!
So stop telling people things that are flat-out wrong.While I am sure you are correct let us not further confuse people!
No. It absolutely definitely isn't. It isn't an amount of energy. It's how fast energy is being delivered. The term kW is a power level that explains what rate of charging speed someone can expect. A normal 120V household outlet, delivering 12 amps into the car is a bit over a kW, around 1.4 kW. That lets you know that it's slow charging speed compared to a different source that is 7 kW or a Supercharger that is 100+ kW.
Sure, battery capacity is amounts of energy, so kWh is correct.
I don't wish to do it every single time, and I frequently let them go and don't try to do that, but it's worth doing every once in a while, especially for people who have been on here quite a while and give a lot of information and advice. It's worthwhile for you to have this information. So what we REALLY don't need is for you fighting us and disagreeing with us when we are trying to give correct information.
kW is for charging power (equivalent to charging speed)
kWh is for amounts of energy
Both are important things to know and talk about, and it really does help some when people are asking and answering questions to know whether they are referring to amounts of energy or charging speed.
That's what kilojoules and megajoules are for! And while I didn't say it outright, I meant saying/using joule in all of its metric forms like kJ and mJ, etc. I also understand why electric bills and everything else use Wh/kWh because that's how power is measured and billed by the utility companies, but J/kJ/mJ just makes more sense in terms of capacity. We don't measure how much water we use on a per hour basis dammit!
ATPMSD
Active Member
I am not fighting you, just saying what has been posted. This is from Electrek
I am really trying to understand the point you are trying to make.
- kW (kilowatt) – A unit of measurement to express the output power of the electric motor. Think of it as how much energy the motor generates in a given amount of time. 1 kW = about 1.34 HP.
- kWh (kilowatt-hours) – A unit of energy marking the energy transferred in one hour by one kilowatt of power. EV battery capacity is measured in kWh, so think of it as your vehicle’s gallons of gas in its tank.
I am really trying to understand the point you are trying to make.
OK. Energy delivery per hour is "power", which is just kW. kWh / h See how the hours in the numerator and denominator cancel out, and the resulting unit for power is just kW?
So kWh / h would be a complicated substitute for kW as a power level, but still correct. But you were using:
kW / h
That is kWh / hour / hour
That's energy per time per time, and is like the second derivative and doesn't really refer to anything we talk about here. It's like if someone had a messed up electrical system, like when Superchargers are malfunctioning, and their power levels keep dropping to 10 kW and then spiking back up to 100 kW and then dropping off to 10 kW again. How fast the power level is rising or falling could be in kW / hour.
Power (kW) is the rate at which you recharge your battery. Energy (kWh in this case) is the amount of energy deposited into your battery pack. Your confusion appears to stem from how confusing "kWh" is as a measure of energy, and if you ask me, is another reason why kWh should just be done away with...
Charging your car at a rate of 10kW for 2 hours would put 72MJ into your 360MJ battery for your Model S LRP
Well this thread took a turn.
To clarify I will be paying for whatever charger is installed but the office pays the electric bill. I’m the only EV there and that likely won’t change. Not sure if this changes anyones outlook.
I guess the other question is, Is there a benefit of charging vs not charging in terms of battery longevity. If I discharge ~30% of my battery daily. Is it best to charge twice daily (once at work and once again at home)
To clarify I will be paying for whatever charger is installed but the office pays the electric bill. I’m the only EV there and that likely won’t change. Not sure if this changes anyones outlook.
I guess the other question is, Is there a benefit of charging vs not charging in terms of battery longevity. If I discharge ~30% of my battery daily. Is it best to charge twice daily (once at work and once again at home)
An outlet is perfectly acceptable to use outside in all weather conditions. I used a covered 110 V outlet for about 16 months at work to charge my EV while I was working, through rain, snow, and wind. Outdoor outlets are made to be used outdoors.
It’s nice that your employer is putting in a charger for you but at 80-mile roundtrip I don’t see it as even necessary. Our work offers free L2 charging but most of us Tesla owners left the chargers for folks with eGolfs or Leafs, unless we happen to be really low on charge.
The argument for the NEMA serving more different EVs makes sense. Even if you went with the Wall Connector at the office you would eventually be sharing it with others as more employees get a Tesla. I wonder why your employer doesn’t just install a more universal L2 J1772?
The argument for the NEMA serving more different EVs makes sense. Even if you went with the Wall Connector at the office you would eventually be sharing it with others as more employees get a Tesla. I wonder why your employer doesn’t just install a more universal L2 J1772?
While I am sure you are correct let us not further confuse people!
Right or wrong in the EV world the term kW is generally accepted to be the amount of energy delivered over the course of one-hour while kWh refers to battery capacity. If you wish to correct this everytime it is posted you will have a new full time job. I wish you well!
If you turn on 10 lamps that have 100 watt bulbs, you are instantaneously drawing 1,000 watts of power or 1 kW.
If you let those 10 lamps stay on for one hour, you will have consumed 1 kilowatt hour of energy or 1 kWh. Our home electric bills are calculated based on kWh's consumed.
Yes, EV batteries are rated in kWh. Theoretically, a 75 kWh battery can deliver 1 kW of power for 75 hours.
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