Two many EV's in one home?

[FlasherZ]

There's something to be said for the "plug it in and forget it" convenience that I believe isn't being reflected here. Yes, it *is* easy to go and swap the plugs... until the first time you forget, or you have to interrupt your company / conversation to do so, etc. The user experience, the ease-of-use is the most critical aspect.

We can argue whether the right solution is HPWC or a UMC, whether it's 240V/40A, 240V/30A, 120V/16A, or 120V/12A... everyone will have to adjust based on the electrical service capacity of her/his home, the mileage need, adjusts charging times, etc., but the most important element for me will be that no matter the number of EV's I have, a cord hangs for each to plug in the moment the car arrives back at the garage.

 

[Lloyd]

In my case I have a Toyota Rav 4 EV, which has charge timing by " Time to be finished charging" I start charging the Tesla at the beginning of my lowest rate, and have to Toyota to be finished at the time we normally leave in the am. Spreads out the usage a little.


It would be nice if Tesla gave us the option to Finish Charge by Time as well.

 

[widodh]

There's something to be said for the "plug it in and forget it" convenience that I believe isn't being reflected here. Yes, it *is* easy to go and swap the plugs... until the first time you forget, or you have to interrupt your company / conversation to do so, etc. The user experience, the ease-of-use is the most critical aspect.

We can argue whether the right solution is HPWC or a UMC, whether it's 240V/40A, 240V/30A, 120V/16A, or 120V/12A... everyone will have to adjust based on the electrical service capacity of her/his home, the mileage need, adjusts charging times, etc., but the most important element for me will be that no matter the number of EV's I have, a cord hangs for each to plug in the moment the car arrives back at the garage.

See the solution from Keba I posted above. It does exactly that.

 

[Palpatine]

If your panel is getting crowded is this possible?
Your house is using very little electricity at night. You could have your dryer in the same circuit as one of your 14-50 EV recharging outlets.
Just be aware that dryer cannot be used after midnight when the EV is scheduled to be recharging.

 

[Lloyd]

Um... No you can't! It is not to code.

If your panel is getting crowded is this possible?
Your house is using very little electricity at night. You could have your dryer in the same circuit as one of your 14-50 EV recharging outlets.
Just be aware that dryer cannot be used after midnight when the EV is scheduled to be recharging.

 

[FlasherZ]

If your panel is getting crowded is this possible?
Your house is using very little electricity at night. You could have your dryer in the same circuit as one of your 14-50 EV recharging outlets.
Just be aware that dryer cannot be used after midnight when the EV is scheduled to be recharging.

You should not be doing this with your electric dryer receptacle. However, if you have limited space in your panel you may share the same 40A or 50A circuit for multiple NEMA 14-50 outlets. You may NOT share the same circuit with an HPWC, regardless of its current setting.

You must take steps to ensure you don't offer a larger load - you risk tripping the circuit breaker and causing trouble for your charging. But it is legal to code to place multiple NEMA 14-50 receptacles on a 50 amp circuit breaker.

EDIT: I was asked privately why you can't do this with your electric dryer receptacle. It is because most electric dryer receptacles are typically rated at 30A, and you may not place both 30A and 50A receptacles on the same branch circuit. (NEC 210.21(B)(3)) A 50-amp rated branch circuit must have 50-amp receptacles only, and a 30-amp rated branch circuit must have 30-amp receptacles only. In any case, with the exception of normal household 125V/15A receptacles on a 20A circuit, receptacles must not be rated less than the branch circuit's rating (e.g., you may not put 2 NEMA 14-50's on a 100A circuit). You MAY install a NEMA 14-30 on the same branch circuit as your dryer receptacle for electric car charging, but you'll be limited to 24A.

 

[Eberhard]

The only solution to this problem is "managed charging" via the pilot signal to the HPWC.

The meter is counting the current drawing from the net. If the current reaching the maximum level, the HPCW is set to draw less current.
Within this calculation can also included a pv-system on the roof to maintain charging without drawing power from the grid.

 

[andrewket]

The Volt is a complete dog once we get spoiled with the MS. :biggrin: Ive seen a couple of good ideas here to consider. Namely getting just one HPWC. The trick is moving all the charging to night time.

The volt isn't that bad if you primarily use it for short commutes. It's our kid transport car to school, activities, etc. We do have to charge twice a day, but we're 99% EV miles after 1,400 miles so far (just picked up last month.)

 

[strider]

We are running 2 EV's just fine w/ 100A service to the entire house. Each Tesla gets a 30A circuit so charges at ~20mi/hr. Our off-peak rate runs from 11pm-7am so plenty of time to recover for the driving we do and we can still run a load of laundry while the cars are charging. Unless you're a traveling salesman, realtor, or have a 200-mile commute I just don't see the need for 80A circuits to all your cars. You're just paying a lot of money to electricians IMO.

 

[LytHka]

Sorry to resurrect an old thread but I couldn't find anything relevant.

Say I want to start a taxi service using only Teslas. What would be the best way to charge a small fleet of 4-5 Model S's about 235 miles of range in ~4 hrs every night?

Could a qualified electrician install a breaker system that can handle that kind of load on a regular basis? Will my local power company even be able to supply me with that kind of juice to one location?

 

[Lloyd]

Sorry to resurrect an old thread but I couldn't find anything relevant.

Say I want to start a taxi service using only Teslas. What would be the best way to charge a small fleet of 4-5 Model S's about 235 miles of range in ~4 hrs every night?

Could a qualified electrician install a breaker system that can handle that kind of load on a regular basis? Will my local power company even be able to supply me with that kind of juice to one location?

I would think at a bank of 4-5 HPWC's would be the most cost effective, with Dual onboard chargers would work fine. If a little charging was done at shift change or breaks also you could do this with a 400 amp service.

 

[glhs272]

Well, simple math dictates:
-One model S with twin chargers requires 100 amp service but runs at 80amps for continuous loads.
-If you charge all 5 cars at the same time you would need 500 amp panel at minimum just for the cars.

You could get by with less if you could lengthen the charge time (use less amps) or not charge all vehicles at the same time by rotating which vehicles were charging vs which were driving.

 

[LytHka]

I would think at a bank of 4-5 HPWC's would be the most cost effective, with Dual onboard chargers would work fine. If a little charging was done at shift change or breaks also you could do this with a 400 amp service.

I was thinking that same setup.

Well, simple math dictates:
-One model S with twin chargers requires 100 amp service but runs at 80amps for continuous loads.
-If you charge all 5 cars at the same time you would need 500 amp panel at minimum just for the cars.

You could get by with less if you could lengthen the charge time (use less amps) or not charge all vehicles at the same time by rotating which vehicles were charging vs which were driving.

Would most likely want all 5 vehicles charging at the same time (between 2AM and 6AM) so they can be driving with almost max range from the start of 1st shift.

So what you guys are saying is it would be feasible with a high amperage circuit breaker. Thanks

 

[ItsNotAboutTheMoney]

Well, simple math dictates:
-One model S with twin chargers requires 100 amp service but runs at 80amps for continuous loads.
-If you charge all 5 cars at the same time you would need 500 amp panel at minimum just for the cars.

You could get by with less if you could lengthen the charge time (use less amps) or not charge all vehicles at the same time by rotating which vehicles were charging vs which were driving.

If only Tesla had some kind of idea for a single L2 charging unit that could apportion charge appropriately amongst multiple vehicles. Would be useful in multi-PEV homes and shared dwellings...

 

[glhs272]

I would also take into consideration your mileage requirements. As all of us Model S owners know, you can't always expect to get the full rated range if it is really cold out. As cabin heating and pack heating takes a significant amount of energy. This would be even worse if your driver would be sitting at some location with the heat on and not charging. I have found that running the heat at 0*F enough to keep the cabin at a warm 72* is like driving at 55 mph. Heavy air conditioning takes some energy but not nearly as bad as heating in the cold winter.

 

[Cottonwood]

I would think at a bank of 4-5 HPWC's would be the most cost effective, with Dual onboard chargers would work fine. If a little charging was done at shift change or breaks also you could do this with a 400 amp service.

Because this is commercial, you may get 3-Phase service. With 208V, 400A, 3-Phase service, you can get 231A (400/sqrt(3)) on each of 3 208V phases. With this, you could connect 2 HPWC's on each phase (6 total) and still have 30A or so on each phase for other things in the facility. Planning for the future, you may just want to get 600A or 800A service to start with.

As others have said, stuff happens, whether it is a long distance fare, cold weather, etc. You should plan on shorter, intermediate charges during the day to top up the battery, or maybe price a CHAdeMO with an adapter for quick charging.

Good Luck!

 

[brianman]

Say I want to start a taxi service using only Teslas. What would be the best way to charge a small fleet of 4-5 Model S's about 235 miles of range in ~4 hrs every night?

Rent an office near a supercharger.

 

[walla2]

I have this setup:

1. Model S P85 on a NEMA 14-50
2. Roadster 2.0 on a 110 for storage. Switch to 50 for fast charge
3. Zero FX on a 110

If I go AND Model X, I'll likely add a 80 A service and then have more options to slow, medium, and fast charge without over doing the panel or having 4 HPWCs in the garage on their own panel. A little juggling with the charger, but I won't be able to drive/ride all four at once.

 

[arg]

If only Tesla had some kind of idea for a single L2 charging unit that could apportion charge appropriately amongst multiple vehicles. Would be useful in multi-PEV homes and shared dwellings...

It doesn't need Tesla to do this. It's very straightforward to do just within the standard J1772 parameters. I continue to be amazed that none of the established EVSE manufacturers have bothered.

 

[widodh]

It doesn't need Tesla to do this. It's very straightforward to do just within the standard J1772 parameters. I continue to be amazed that none of the established EVSE manufacturers have bothered.

Very odd indeed. In the Netherlands it's very normal to have such a solution. We have a 22kW EVSE at our office which outputs 1x22kW or 2x11kW depending on the amount of vehicles plugged in.