electric car charging requirements

Status
Not open for further replies.

DaveBowden

Senior Member
Location
St Petersburg FL
A customer called today for an estimate to upgade his service from 200 amps to 400 amps. He is replacing his 5 ton a.c. system with a 3 ton and a 2 ton system and has no more room in his panel. when I told him he probably didn't need to upgrade his service he said he was going to be getting 2 electric cars and they each had a peak recharging load of 80 amps @ 240 volts - a total of 160 amps peak load.
I have a hard time believing that, but don't know where to look to verify it.
If he is right, where would you find a cord or receptacle rated for 80 amps?
 

drive1968

Senior Member
The amps required depends on the car. For example, I have seen a Nissan Leaf charging station that required a 40 amp breaker. I've read the the Chevy Volt has a charger that requires a 40 amp breaker. But the Tesla car has an option for a 90 amp breaker for its charging pack. Some cars also have the option to run off a standard 20 amp receptacle.

So it really depends on which cars the customer is planning on charging and also how quickly he wants to charge the car.
 

westelectric

Senior Member
Agreed. For example the volt has a 240v 40a charger and a simple 120v 20a charger. All depends on how much $ the buyer wants to spend and how quickly they want to charge their car..
The amps required depends on the car. For example, I have seen a Nissan Leaf charging station that required a 40 amp breaker. I've read the the Chevy Volt has a charger that requires a 40 amp breaker. But the Tesla car has an option for a 90 amp breaker for its charging pack. Some cars also have the option to run off a standard 20 amp receptacle.

So it really depends on which cars the customer is planning on charging and also how quickly he wants to charge the car.
 

jim dungar

Moderator
Staff member
Location
Wisconsin
Occupation
PE (Retired) - Power Systems
I believe that Square D and Leviton, among others, are now offering EV charging stations.
I think they come in these flavors:
Level 1 is slow charge indoor.
Level 2 is slow charge outdoor.
Level 3 is fast charge - probably needs 3-phase

You should be able to find information on their websites.
 

gndrod

Senior Member
Location
Ca and Wa
EV types?

EV types?

A customer called today for an estimate to upgade his service from 200 amps to 400 amps. He is replacing his 5 ton a.c. system with a 3 ton and a 2 ton system and has no more room in his panel. when I told him he probably didn't need to upgrade his service he said he was going to be getting 2 electric cars and they each had a peak recharging load of 80 amps @ 240 volts - a total of 160 amps peak load.
I have a hard time believing that, but don't know where to look to verify it.
If he is right, where would you find a cord or receptacle rated for 80 amps?

Most of the new charge stations for residential in the US will be hard wired and have an SAE-J1772 standard attachment at the EV. The Tesla, at this time, uses it's own EV connector with adapter cables to either a standard 120V receptacle or a hardwired station for 70 A @ 240V, 1ph energy demand max from the vehicle. What are the cars the customer will be charging?
 

Sparky555

Senior Member
Give him a quote for the upgrade and offer a load calc (for a fee) to find out if a larger 200A service or subpanel would be adequate.
 

gary

Senior Member
Location
California
Occupation
Retired electrical contractor / general contractor
Check with your local utility for EV requirements

Check with your local utility for EV requirements

You should check with your local utility before making this kind of service change. Here in California, Pacific Gas & Electric just made several changes to their "green book" indicating that in order for EV owners to get the lowest off-peak rates they will need to have a separately metered charging station. (Rates as low as $.05 / KW hr between midnight and 7AM)
 

readydave8

re member
Location
Clarkesville, Georgia
Occupation
electrician
A customer called today for an estimate to upgade his service from 200 amps to 400 amps. He is replacing his 5 ton a.c. system with a 3 ton and a 2 ton system and has no more room in his panel. when I told him he probably didn't need to upgrade his service he said he was going to be getting 2 electric cars and they each had a peak recharging load of 80 amps @ 240 volts - a total of 160 amps peak load.
I have a hard time believing that, but don't know where to look to verify it.
If he is right, where would you find a cord or receptacle rated for 80 amps?
Sell him a 400a service to make him happy, make some money to make you happy.
 

K8MHZ

Senior Member
Location
Michigan. It's a beautiful peninsula, I've looked
Occupation
Electrician
It seems the customer has done his homework.

The standard allows for charging at home, at work, or at public charging stations. The standard as now written addresses two charging levels:

AC Level 1: 120 V, 1 phase, up to 16 A

AC Level 2: 240 V, 1 phase, up to 80 A

The J1772 task force has begun work on specifications for higher-voltage, fast-rate dc charging. "Only the first chapter of the electrification of the vehicle has been written," said Kissel. "The committee is eager to write the next chapter."

http://www.sae.org/mags/AEI/7479
 

Strife

Senior Member
I seriously doubt that.
500A cranking, that's at 12V, at 240 is 25A.
Now look backwards, if the peak at 240 is 80A, the 12 volt from the charger to the battery would be? 1600A? Even at that short of a distance, I'd hate to see the size of that wire.
I think he's looking at the 12V Peak, (4-5A at 240), which makes a lot more sense.

A customer called today for an estimate to upgade his service from 200 amps to 400 amps. He is replacing his 5 ton a.c. system with a 3 ton and a 2 ton system and has no more room in his panel. when I told him he probably didn't need to upgrade his service he said he was going to be getting 2 electric cars and they each had a peak recharging load of 80 amps @ 240 volts - a total of 160 amps peak load.
I have a hard time believing that, but don't know where to look to verify it.
If he is right, where would you find a cord or receptacle rated for 80 amps?
 

Strife

Senior Member
Just thought about your OP and reading this I just realized something:
He's not paying for this, we are. With all these rebates and crap going around ( Sorry, I know some are legitimate, but I think a lot of it is crap), he probably won't pay a dime, that's why he wants it upgraded. He probably found a loophole in this green thing crap (again, a lot of it is legitimate, but there'll always be people who can find a way to abuse rules) to get something for free. So why not?
Sorry, I'm all for saving the planet and I'm all for saving energy, but a lot of this green movement is just new ways for people to abuse the taxpayers.
I installed CFL's in my house when they cost 15-20 dollars a piece, no one reimbursed me for them, and I didn't need to, out of 20 lamps, I changed maybe 3 so far (in 10 years) and I know the energy savings paid for them least three times.
And the requirements you referring in the link, are probably another way to skim the taxpayers. After all the electric manufacturers have to cash in in the (as above mentioned) green movement. So what's a few more dollars between friends?

16.8KW? Can you imagine the size of that battery? I installed 40KW backups and their battery banks wouldn't fit in two cars.

We're doing toe upgrade Tuesday. I wasn't about to try to talk him out of it, I just told him I didn't think it was necessary. He wantsit and is willing to pay for it so I'm willing to do it.
This is a link to what he was referencing:
https://secure.wikimedia.org/wikipedia/en/wiki/SAE_J1772
 

K8MHZ

Senior Member
Location
Michigan. It's a beautiful peninsula, I've looked
Occupation
Electrician
I seriously doubt that.
500A cranking, that's at 12V, at 240 is 25A.
Now look backwards, if the peak at 240 is 80A, the 12 volt from the charger to the battery would be? 1600A? Even at that short of a distance, I'd hate to see the size of that wire.
I think he's looking at the 12V Peak, (4-5A at 240), which makes a lot more sense.

You incorrectly are assuming a 12 volt system.

DC systems are from 96 to 192 volts. AC systems go over 300 volts. The Tesla uses 375 volts.

As I said before, the customer has done his homework.

I can't say the same for people on this forum giving out advice for this new technology.
 

GeorgeB

ElectroHydraulics engineer (retired)
Location
Greenville SC
Occupation
Retired
+1 on Marky the Sparky ...

Let's look at it another way. An automobile probalby averages (keep numbers easy to work with) 24kW average while moving. At 240V, that is 100A. Charging efficiency is less than 100%. Let's ASSUME 75%. So for every hour of operation at that load, it would take 2 hours at 75A to put the energy back in. As I read the electric vehicle discussions, 120 miles seems to be a distance they want ... so if 60mph is the base, we'd have 2 hours from the battery, 4 hours to recharge.

These numbers all fit my "reasonableness" criteria.

The long range goal of the utilities is to schedule charging based on demand. I don't know the demand schedule, but I'd GUESS there is half of the 24 hour day that would offer good opportunities to use that power from the nuclear stations efficiently ...

seems reasonable ...
 

readydave8

re member
Location
Clarkesville, Georgia
Occupation
electrician
or not?

or not?

Just thought about your OP and reading this I just realized something:
He's not paying for this, we are. With all these rebates and crap going around ( Sorry, I know some are legitimate, but I think a lot of it is crap), he probably won't pay a dime, that's why he wants it upgraded. He probably found a loophole in this green thing crap (again, a lot of it is legitimate, but there'll always be people who can find a way to abuse rules) to get something for free. So why not?
Sorry, I'm all for saving the planet and I'm all for saving energy, but a lot of this green movement is just new ways for people to abuse the taxpayers.
I installed CFL's in my house when they cost 15-20 dollars a piece, no one reimbursed me for them, and I didn't need to, out of 20 lamps, I changed maybe 3 so far (in 10 years) and I know the energy savings paid for them least three times.
And the requirements you referring in the link, are probably another way to skim the taxpayers. After all the electric manufacturers have to cash in in the (as above mentioned) green movement. So what's a few more dollars between friends?

16.8KW? Can you imagine the size of that battery? I installed 40KW backups and their battery banks wouldn't fit in two cars.
Then again maybe customer wants 400a service for whatever reasons and is willing to pay for it himself.
 

cadpoint

Senior Member
Location
Durham, NC
In posting another link today, I noticed that on the home page a major electricial manufacture is ready to release it's UL approved charger station in April, the press release happens to mention both UL listing and the SAE numbers that their application is using.

Leviton its the Evr-Green? 160 Level 2 Home Charging Station :)
 

broadgage

Senior Member
Location
London, England
Batteries used for standby purposes are almost allways of the lead acid type as these are cheap and simple, such a battery able to supply 40 KWH or more would indeed not fit in a car.
The batteries used in a modern EV are of more advanced types and some store a lot more than 40 KWH.
The charging requirement of 80 amps at 240 volts is therefore reasonable for fast charging.
Most EVs can be charged from smaller supplies, but this would take a long while for the larger ones. Some work places provide 120 volt 20 amp outlets for chargers with a 16 amp input.
In an 8 hour day that is about 12 KWH into the battery, very worthwhile but unlikely to fully charge a large EV.
 
Status
Not open for further replies.
Top