Charging speed at home vs work

[SnBGC]

Why not? That's the first thing that needs to change. When your car is fully charged, you go out and move it so that others can use the charger. This is regardless of whether it's a BEV or PHEV.

Agree.
Many plug in vehicles have an app or some way to communicate when charged so they should move. We have 2 plugs at work and 4 plug in vehicles and we share just fine.

ChargePoint app has a feature where it will let you get in line for charging in the event the plug(s) is/are occupied. Then when the car is done, the owner is asked to move because someone else it waiting. The business owner can even allow free charging but then charge a fee for not moving the vehicle.

When we install the CT-4000 units, we normally recommend free charging for employees, $1.00/hr for public. Then a 15 min grace period to move after charging is complete before a $5/hr rate begins for parking in an EV space while fully charged. That usually gets people to move. Except surgeons.....they don't care. They will leave their car there all day and pay the fee. I guess they have a lot of cash burning a hole in their pockets....

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[RMoore]

Why not? That's the first thing that needs to change. When your car is fully charged, you go out and move it so that others can use the charger. This is regardless of whether it's a BEV or PHEV.

Agree in principle, but in practice, a bit more nuanced it would seem. The times when I've left early, say at 4 or 4:30, most of the cars are still charging, including mine (at least that's my interpretation of the light on the Tesla destination charger scrolling down every few seconds). At 6-7kW, you will only charge a little over half of our battery capacity (assuming ER) in a typical 9-5 day. Of course it's all doable but it requires some alterations in behavior. Folks would have to set lower targets for their charging at work and also be able to jump out at certain times of the day to move their cars--not always easy with back to back meetings that some of us have at times. I suppose if demand outstripped supply and our company wasn't ready to add more stations, we could come together as an EV community and work this out, but these are not easy things to accomplish (sadly).

 

[shutterbug]

120v isn't really that useful except for visiting friends or family and staying the weekend or longer. It charges at 2-4 miles per hour (depending on the EV).

When I had my plug-in CMax, 110v charging at work would have been pretty handy. After 9 hour day my battery would have been full.

 

[generaltso]

Agree in principle, but in practice, a bit more nuanced it would seem. The times when I've left early, say at 4 or 4:30, most of the cars are still charging, including mine (at least that's my interpretation of the light on the Tesla destination charger scrolling down every few seconds). At 6-7kW, you will only charge a little over half of our batter capacity (assuming ER) in a typical 9-5 day. Of course it's all doable but it requires some alterations in behavior. Folks would have to set lower targets for their charging at work and also be able to jump out at certain times of the day to move their cars--not always easy with back to back meetings that some of us have at times. I suppose if demand outstripped supply and our company wasn't ready to add more stations, we could come together as an EV community and work this out, but these are not easy things to accomplish (sadly).

It's really not that complicated. If a car is plugged in all day ACTIVELY charging, that's fine. No need to move it. If a car is done charging at any point, go move it as soon as you can. I understand you may be in a meeting or something, so go move it right after. We have a free 2-port ChargePoint commercial station at work, and there are currently about a dozen cars that regularly use it. It's very common for both plugs to be in use, but at some point during the day one usually frees up when that car is done charging. Every now and then a new car joins the fray that doesn't know the etiquette. After a couple times blocking the charger with their fully charged car, they get a note on their windshield asking them to be courteous to other EV drives and move their car when its done charging. It never takes more than one note.

 

[RickMachE]

Except surgeons.....they don't care. They will leave their car there all day and pay the fee. I guess they have a lot of cash burning a hole in their pockets....

Think of how much a surgeon makes per minute - in surgery, or meeting with a patient. Why should they spend 15 minutes on elevators and walking out to move their vehicle?

 

[RMoore]

It's really not that complicated. If a car is plugged in all day ACTIVELY charging, that's fine. No need to move it. If a car is done charging at any point, go move it as soon as you can. I understand you may be in a meeting or something, so go move it right after. We have a free 2-port ChargePoint commercial station at work, and there are currently about a dozen cars that regularly use it. It's very common for both plugs to be in use, but at some point during the day one usually frees up when that car is done charging. Every now and then a new car joins the fray that doesn't know the etiquette. After a couple times blocking the charger with their fully charged car, they get a note on their windshield asking them to be courteous to other EV drives and move their car when its done charging. It never takes more than one note.

I didn't say it was complicated but that doesn't mean it's straightforward to implement and given that it hasn't been all that crowded typically (many come in 2-3 days a week) people haven't worried about it. But if we did, it would require a collective agreement that that should be the approach and there are practical limitations. My sense is that only 1-2 cars would finish charging in time for it to matter. But then it requires some sort of coordination. How would I know that someone moved their car and that a slot is available? It is a 15 min round trip from office to charging station and I don't always have that 15 min buffer so I'm not going to keep walking over to check with the hope that it will be available. It's just not important enough--I can charge at home. To really make this work we would have to set up a page on our company's website where we log in, check our charging periodically, then move our car, then change the status on the web page that sends an alert to the rest of those who want to know that a slot is available. All doable, but there would have to be a real groundswell of demand to make that happen at a big company. I don't think it is as simple as you are suggesting.

 

[RickMachE]

They are merely offering the plugs as an amenity for the staff.....sort of like coffee service for the office. Abuse the amenity, then expect to have to start paying to charge.

Agree, their #1 reason COULD BE is providing an amenity for the staff.

However, in some communities, they are REQUIRED to have X number of spaces of free EV charging to be able to build their building. See example below.

In addition, employers want to encourage their employees to commute in a manner more friendly to the environment. Many pay for mass transit passes. Or provide EV and related vehicles with special parking perks as a reward.

One example of an ordinance:

The new EV parking ordinance requires three types of EV parking spaces in new development site plans: some with EV chargers installed, and some either “EV capable” or “EV ready,” making it easy to add chargers in the future.

The ordinance requires “Level 2” chargers at a minimum, which are less expensive than rapid chargers.

There are varying levels of EV requirements for different kinds of developments.

For multi-family housing developments, such as condo or apartment buildings, the ordinance requires 10% of required parking spaces to have EV chargers installed, 25% to be EV-ready and 65% EV-capable.

 

[SnBGC]

Think of how much a surgeon makes per minute - in surgery, or meeting with a patient. Why should they spend 15 minutes on elevators and walking out to move their vehicle?

True. Plus putting down the scalpel to move your car would be frowned upon.

 

[generaltso]

I didn't say it was complicated but that doesn't mean it's straightforward to implement and given that it hasn't been all that crowded typically (many come in 2-3 days a week) people haven't worried about it. But if we did, it would require a collective agreement that that should be the approach and there are practical limitations. My sense is that only 1-2 cars would finish charging in time for it to matter. But then it requires some sort of coordination. How would I know that someone moved their car and that a slot is available? It is a 15 min round trip from office to charging station and I don't always have that 15 min buffer so I'm not going to keep walking over to check with the hope that it will be available. It's just not important enough--I can charge at home. To really make this work we would have to set up a page on our company's website where we log in, check our charging periodically, then move our car, then change the status on the web page that sends an alert to the rest of those who want to know that a slot is available. All doable, but there would have to be a real groundswell of demand to make that happen at a big company. I don't think it is as simple as you are suggesting.

With ChargePoint, you click a button in the app to be alerted when the charger is available. But I see how it would be more difficult if the chargers aren’t networked.

 

[SnBGC]

With ChargePoint, you click a button in the app to be alerted when the charger is available. But I see how it would be more difficult if the chargers aren’t networked.

Yeah. We just created an EV e-mail group and we let each other know when our car is done. None of us have ANY concern about another employee unplugging our car to charge their own. We are all cool with it. We have 4 parking spaces that are serviced with 2 plugs so nobody has to move their vehicle.

My car has the largest battery so parking space next to me is the owner with the smallest battery (which is a PHEV). The other two spaces are BEVs with 33.5kWh and 24kWh packs. Our agreement is the vehicle with the smaller pack gets priority.

I usually get to work very early and plug in. By the time the PHEV arrives, I am fully charged but if not, then she just unplug my car to charge hers and I am totally fine with it.

As more employees begin buying plug in vehicles then we are going to need (or want) to install more plugs. Something we have figured into our budget.

 

[RMoore]

With ChargePoint, you click a button in the app to be alerted when the charger is available. But I see how it would be more difficult if the chargers aren’t networked.

Right, these are all Tesla chargers. It would have to be done via a website or as Greg mentioned above, an email list of some sort. Or maybe a video feed that we have access to--there are security cameras throughout the garage. Again, lots of ways to do it if there is enough interest, just takes some doing.

 

[Mach-Lee]

Home: 40A x 238V = 9.5 kW
Work: 32A x 188V = 6.0 kW

Chargers at work are often 208V instead of 240V, which will reduce charging speed. In addition, they are often 32A or less vs. 40 or 48A for home chargers. Last, chargers at work are often outside a long distance from the panel, so they tend to have high voltage drops which also reduces charging speed.

As others have said, load sharing is a possibility, every setup is different. If you have load sharing you may notice a big difference in charging speed from day to day depending on who is plugged in when. At my work there is no load sharing but we only have a couple chargers. Load sharing is more likely in larger installs (5+ stations).

 

[daemonic3]

Good to know. But the "step aside" thing doesn't really apply to the work situation unless folks moved their cars during the day. They currently don't but I would be fine with signs that asked people to do that (e.g. at lunch time) so that others can get some charging time. This is something of a pilot program--my hope is that they will see that the chargers are being used and will install more of them. It is certainly nice of them to do that given the expense (though this is a big Fortune 500 company so can afford it more than a smaller company).

My work has L2 Chargepoints for 10c/kWh (corporate discount) and after 3hrs they start charging $1/hr parking. Outside of 8a-5p M-F the parking fee doesn't apply. I assume that is comparable to many businesses in silicon valley, but haven't investigated. The 3hr limit is intended to just get most people enough for the work commute. Not intended as a parking space, nor as your primary source of charge.

Also any single-receptacle 120V plug is free to use in any parking garage, no fee or limitation (first come gets dibs).

 

[Triggerhappy007]

You bring up some excellent points that lead to me ask another question, one that reflects my lack of knowledge about plug in hybrids. My garage at work also has a block of charging stations that are at 110V (or close to that at least). They have been there for a few years and predate the higher voltage (208 or 240V) Tesla destination chargers that are located in a different area (I have to check if the 110V stations are just receptacles or if they are Tesla units). Would 110V charging be sufficient for the typical plug in hybrid? I ask because I notice that there are several plug in hybrids that routinely charge at the high voltage Tesla destination chargers and I was trying to figure out if I should be annoyed at that when there are no slots left, or if it is perfectly reasonable for them to charge there.

It depends on the type of plug in hybrid since they have different battery capacities. I have had the Prius Prime and that takes about 5 hours at 120V. I have a Pacifica Hybrid and that takes about 12 hours. If I worked there I would charge at 120V unless it takes more than 8 hours to charge my battery.

I have the opposite feelings as others with priority going to BEVs since they don't have a backup engine. I guess it depends on what type of plugs and how you work it out.

 

[RMoore]

It depends on the type of plug in hybrid since they have different battery capacities. I have had the Prius Prime and that takes about 5 hours at 120V. I have a Pacifica Hybrid and that takes about 12 hours. If I worked there I would charge at 120V unless it takes more than 8 hours to charge my battery.

I have the opposite feelings as others with priority going to BEVs since they don't have a backup engine. I guess it depends on what type of plugs and how you work it out.

We’ll, one of the cars that’s there all the time is a Pacifica so that makes sense.

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