Assumptions for future proofing for residential electric car

drcampbell

Senior Member
Location
The Motor City, Michigan USA
Occupation
Engineer
It may be like the computer world, motor efficiency may go up, I can remember running 60 amp three phase power to servers in computer rooms, now, it’s a 20 circuit that runs a server many times more powerful. ...
I foresee the opposite trend in EVs and chargers: Greater battery capacity and faster charging, either of which means installing more ampacity.
Motor & controller efficiency isn't likely to rise much -- it's already 80-plus percent -- and if it does, it will be used to increase range; not traded off for smaller battery capacity or slower charging.
 

retirede

Senior Member
Location
Illinois
I foresee the opposite trend in EVs and chargers: Greater battery capacity and faster charging, either of which means installing more ampacity.
Motor & controller efficiency isn't likely to rise much -- it's already 80-plus percent -- and if it does, it will be used to increase range; not traded off for smaller battery capacity or slower charging.

I’m not convinced that faster charging at home will be necessary. A 48 amp charger can add 100 KWHr to a car in 9 hours. For most EVs today, that over 300 miles worth. Very few people drive 300 miles per day, day in, day out.

I charge about once per week for 4 hours.
 

hillbilly1

Senior Member
Location
Atlanta,Ga
Occupation
Field coordinator/ technical support
I foresee the opposite trend in EVs and chargers: Greater battery capacity and faster charging, either of which means installing more ampacity.
Motor & controller efficiency isn't likely to rise much -- it's already 80-plus percent -- and if it does, it will be used to increase range; not traded off for smaller battery capacity or slower charging.
It may be change in how motivation is done, no longer a motor with mass rotated by a magnetic field, some other new technology which may be even more efficient. Maybe hydrogen based.
 

gadfly56

Senior Member
Location
New Jersey
Occupation
Professional Engineer, Fire & Life Safety
It may be change in how motivation is done, no longer a motor with mass rotated by a magnetic field, some other new technology which may be even more efficient. Maybe hydrogen based.
A paradigm shift is beyond the scope of the OP's question. I agree with drcampbell, the trend is likely to be larger, not smaller chargers. A 30% increase in battery capacity, which may or may not be possible, would cement the high end of current charging options, at least for those travelling longer distances daily.
 

Barbqranch

Senior Member
Location
Arcata, CA
Occupation
Plant maintenance electrician Semi-retired
I believe chargers will be able to anticipate the energy needed in the battery, and how long it has to provide it, and adjust to that. There will be communication between chargers, even not on the same service, that will average out the usage. If you anticipate a greater need than normal, or less time available, you will enter that into the charger for the one time exception. All this will reduce and average the load on POCO.
 

GeorgeB

ElectroHydraulics engineer (retired)
Location
Greenville SC
Occupation
Retired
I’m not convinced that faster charging at home will be necessary. A 48 amp charger can add 100 KWHr to a car in 9 hours. For most EVs today, that over 300 miles worth. Very few people drive 300 miles per day, day in, day out.

I charge about once per week for 4 hours.
AIUI, the rate structure in some locales (California comes to mind) limits charging to a relatively short timeframe, In particular, I've seen there to be only 4 or 5 hours a day. It is possible that there would be more than 1 EV in a household.

I'm NOT discounting your argument; I'm over 95% retired, and drive my vehicle only about (average) 70 miles a week. I cannot imagine that 4 hours a week wouldn't be enough. But I have 1 customer I see once a year that's a 350 mile drive. My test equipment requires my pickup truck.
 

retirede

Senior Member
Location
Illinois
AIUI, the rate structure in some locales (California comes to mind) limits charging to a relatively short timeframe, In particular, I've seen there to be only 4 or 5 hours a day. It is possible that there would be more than 1 EV in a household.

I'm NOT discounting your argument; I'm over 95% retired, and drive my vehicle only about (average) 70 miles a week. I cannot imagine that 4 hours a week wouldn't be enough. But I have 1 customer I see once a year that's a 350 mile drive. My test equipment requires my pickup truck.

Good point about the rate structure issue. I’m not subjected to that (yet).

I do have occasion to take a longer trip. It simply requires a bit of planning.
 

gadfly56

Senior Member
Location
New Jersey
Occupation
Professional Engineer, Fire & Life Safety
I believe chargers will be able to anticipate the energy needed in the battery, and how long it has to provide it, and adjust to that. There will be communication between chargers, even not on the same service, that will average out the usage. If you anticipate a greater need than normal, or less time available, you will enter that into the charger for the one time exception. All this will reduce and average the load on POCO.
You can have it. I refuse to own something that smart, because it's just another gateway into my home networks. Not this boy.
 

qcroanoke

Sometimes I don't know if I'm the boxer or the bag
Location
Roanoke, VA.
Occupation
Engineering
You can have it. I refuse to own something that smart, because it's just another gateway into my home networks. Not this boy.
I just bought a new Toyota Highlander and iam amazed at how smart that vehicle is. I though my phone was smart but it has nothing on the Yota.
 

kwired

Electron manager
Location
NE Nebraska
Does anyone see the amp draw going down on future electric vehicle chargers?
I mean if todays cars require a 50 amp charger does it make sense that future cars may only need a 30 amp charger?
It may be like the computer world, motor efficiency may go up, I can remember running 60 amp three phase power to servers in computer rooms, now, it’s a 20 circuit that runs a server many times more powerful. May not get to that point of efficiency, but you may be right.
I don't see chargers gaining a ton of efficiency though. About the only inefficiency now is the heat given up, so that is about the only place to improve efficiency. There will always be some resistive component to create some heat in the current technologies. If they make the motors more efficient that will just mean more miles per charge, but charging same size battery will still take same time at same charging rate. going from 50 amp charge to 30 amp charge just makes for longer charge time - if anything people are going to want to see faster charge time and reducing losses is about all that will do this without raising charge rate.
 

retirede

Senior Member
Location
Illinois
If they make the motors more efficient that will just mean more miles per charge, but charging same size battery will still take same time at same charging rate.

The way I look at it, the important metric for home charging is miles of range added per hour of charging.
So a more efficient vehicle will add more miles of range per hour of charge.
A person with a 50 mile commute only needs to add 50 miles worth of charge (minimum). A car that gets 4 miles per KWHr needs to add about 13 KWHr, but one that gets 5, only needs to add 10.
 

gadfly56

Senior Member
Location
New Jersey
Occupation
Professional Engineer, Fire & Life Safety
That's proposed language by those 3 authors, right, not anything that has been adopted anywhere?

Cheers, Wayne
True, but government weenies, and legislators especially, being both ignorant and lazy, will treat this as a gift from the gods and run with it.
 

wwhitney

Senior Member
Location
Berkeley, CA
Occupation
Retired
Well, the proposal there basically is:

A single family dwelling with parking should have one parking space with a 40A circuit run to it for a future EVSE.

Multifamily dwellings should have electrical panel capacity for 25% of the parking spots to eventually get 40A circuits, of which 3 out of 5 (15% of total spaces) should get circuits run to them now for eventual EVSEs, and 1 out of 3 of those (5% of total spaces) should actually get EVSEs installed now. Plus a table to tell you how to do the rounding when the total number of spaces is 25 or under.

Sounds like an appropriate step on the path to decarbonization.

Cheers, Wayne
 

kwired

Electron manager
Location
NE Nebraska
The way I look at it, the important metric for home charging is miles of range added per hour of charging.
So a more efficient vehicle will add more miles of range per hour of charge.
A person with a 50 mile commute only needs to add 50 miles worth of charge (minimum). A car that gets 4 miles per KWHr needs to add about 13 KWHr, but one that gets 5, only needs to add 10.
But either way how long it takes depends on what rate the charging equipment is capable of and/or limited to where it can be limited for whatever reasons.
 
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