Faster A/C charging?

[ewoodrick]

I've been following dcbel for quite a while. It seems they may have something actually available now. I was thinking about getting their system to use with our Leaf so the Leaf's CHAdeMO could serve as stationary V2G backup but we got rid of it before dcbel got their product launched.

The debate over onboard -vs- offboard chargers was a big point of discussion back in the '90's. It was as big as inductive -vs- conductive chargers.
GM and Toyota chose offboard inductive (Magnecharger) while Ford and Honda chose onboard conductive (AVCON - that later became J-1772).

Some of the big questions are:
- is it worth hauling the heavy transformer around in your car with you all the time or should we just leave it at the charging site?
- If we're using a public chargers most of the time (including fast chargers), is it worth even paying for our own charger?

Clearly, these were all good topics and, lucky for humanity, NACS (unlike J-1772, Type-2, CCS, and CHAdeMO) supports either onboard or offboard, thus allowing the market to determine which is truly best.

Don't worry folks, there are still the questions of Conductive -vs- Inductive, 3-phase -vs- single-phase, and English -vs- Metric so there will still be plenty to argue about on the internet for a while longer.

Onboard vs offboard is pretty moot, as offboard makes the portable equipment much harder to lug around. And since it would be in your trunk, it might as well be onboard and well integrated.

Inductive? Well, when they can supply the currents required....

Transformer? That is pretty 90's concept, except when you get into the much higher transmission voltages. Switching power supplies have come a long way.

3phase vs 1? That's effectively residential service vs commercial. Not going to get 3 phase at a residence.

 

[Big Earl]

And the mistaken title of the thread makes me think we are topping up the refrigerant in the air conditioning quickly
A/C != AC

Not sure why no one has mentioned DC Charging at home, 25kWs anyone? It likely will be coming down in price and allow DC access to the battery meaning it could provide bi-directional power too, something that would be nice at our cabin. Although I suppose I can also just plug the generator box into the 240v inverter output in the bed of the CT

The percentage of homes with a >25 kVA transformer allocation is probably in the single digits. Lots of homes have 200-amp panels but have less than 40 amps of actual transformer allocation, since on average, most homes only use a fraction of their total capacity at any given time. It isn't uncommon to see a 25 kVA transformer shared with four or five homes. In my previous neighborhood we had seven houses on a 50 kVA transformer. My parents have two 200-amp panels on a 50 kVA transformer, but they paid extra for that to support their all-electric home and have room for future growth. 25 kW of home charging is going to require major infrastructure upgrades for a lot of people.

 

[ewoodrick]

The percentage of homes with a >25 kVA transformer allocation is probably in the single digits. Lots of homes have 200-amp panels but have less than 40 amps of actual transformer allocation, since on average, most homes only use a fraction of their total capacity at any given time. It isn't uncommon to see a 25 kVA transformer shared with four or five homes. In my previous neighborhood we had seven houses on a 50 kVA transformer. My parents have two 200-amp panels on a 50 kVA transformer, but they paid extra for that to support their all-electric home and have room for future growth. 25 kW of home charging is going to require major infrastructure upgrades for a lot of people.

Now don't go inserting reality, so many people are here to prove you wrong!

Yea, 25 kVA residential DC charging? Sounds good until you see the implementation requirements and the fact that the car would probably be cheaper! (or hiring a valet to take car to Supercharger at night)

 

[Earl]

offboard makes the portable equipment much harder to lug around.

Offboard means there is nothing needed to lug around. Its all on the wall.

Inductive? Well, when they can supply the currents required....

This can be a problem above about 20 amps. The EV1 charger was about 20 amps and they did have some charge port cooling issues. It was fine for overnight charging at home.

Transformer? That is pretty 90's concept, except when you get into the much higher transmission voltages. Switching power supplies have come a long way.

There are still big transformers (iron cores and a lot of windings) in modern Switching power supplies used in EV chargers. Sure, they aren't the old 'autotransformers' like we used on our Lionel toy trains that set the voltage with the transformer but that is still the major cost driver for a charger in terms of cost and mass.

3phase vs 1? That's effectively residential service vs commercial. Not going to get 3 phase at a residence.

Cue the Europeans to argue this fact. In Europe, most high-power residential service is 3-phase. That's why they use Type-2 plugs there instead of J-1772. Type-2 have 3 power conductors, one for each phase. They complain about how Tesla/NACS single phase will unbalance the load between the phases to a house.

 

[ewoodrick]

Offboard means there is nothing needed to lug around. Its all on the wall.


This can be a problem above about 20 amps. The EV1 charger was about 20 amps and they did have some charge port cooling issues. It was fine for overnight charging at home.


There are still big transformers (iron cores and a lot of windings) in modern Switching power supplies used in EV chargers. Sure, they aren't the old 'autotransformers' like we used on our Lionel toy trains that set the voltage with the transformer but that is still the major cost driver for a charger in terms of cost and mass.


Cue the Europeans to argue this fact. In Europe, most high-power residential service is 3-phase. That's why they use Type-2 plugs there instead of J-1772. Type-2 have 3 power conductors, one for each phase. They complain about how Tesla/NACS single phase will unbalance the load between the phases to a house.

Offboard DOES mean hauling something around, if you want to charge at someone else's house, like I did this weekend.

But we aren't talking EV1 anymore. And honestly, there are very few 20A power supplies that use transformers anymore. They are all switchers.

There is indeed a utility transformer at a Supercharger site, but as far as I know, all of the voltage conversion from there is down with switching supply modules in the cabinets, Not sure why you brought up autotransformers. Today's switchers, as used in all EVSE and DC charging handle the variable voltages.

I'm not in Europe. You don't seem to be in Europe. It's not a discussion in the US. In Europe Tesla uses 3-phase charging.

 

[israndy]

Cue the Europeans to argue this fact. They complain about how Tesla/NACS single phase will unbalance the load between the phases to a house.

How do you unbalance a panel by pulling 240v?

 

[Earl]

Offboard DOES mean hauling something around, if you want to charge at someone else's house, like I did this weekend.

And honestly, there are very few 20A power supplies that use transformers anymore. They are all switchers.

I think you're addressing your own issue. Low power switching power supplies don't require transformers but they do require inductors and capacitors whose size is roughly proportional to their power handling but you're right, they're fairly small so they aren't much to haul around. In fact, if they are onboard chargers you're always paying for them and hauling them around whether you use them (like you did last weekend) or, apparently, most people don't. I'm actually in your camp in that I would chose to carry the charger around with me all the time so I could plug in to any outlet but apparently you and I are the exception, not the rule. I actually mounted my EV1 home charger on a hand truck and put a 14-50 plug on it so it could be wheeled around (the beast weighed about 80 lbs) and even carried it in the trunk of the EV1 on roadtrips.
The gen1 EV1's 120v/8a portable charger was barely bigger than the cheap L1 J-1772 EVSE "brick" that came with the Chevy Volt or Leaf. It wasn't a big deal to carry.
High power chargers, even with switching power supplies, definitely do require large magnetic devices (iron and windings), whether transformers or just big inductors (not much difference). They make up the bulk of the CHAdeMO and CCS charging pedestals and are in the white cabinets at Tesla Superchargers. You may also recall that the Tesla Roadster, as a weight and bulk reduction measure, used AC Propulsion's patented "reductive charging" that specifically used the motor windings as the inductor in its onboard 70 amp charging circuit.

But we aren't talking EV1 anymore.

I'm pointing out that the same discussion topics still exist. Some things have changed and, perhaps, there is room for the decisions that solidified since to be reopened to see if their reasoning still applies.

 

[Earl]

How do you unbalance a panel by pulling 240v?

By drawing a lot of power from only one phase of a 3 phase supply. From what I've heard, some European power companies get all bent out of shape about this.
While drawing 208v (one leg of a 3-phase circuit) for EV charging in the USA is done fairly regularly, I haven't heard a lot of complaining about it yet.

 

[Big Earl]

By drawing a lot of power from only one phase of a 3 phase supply. From what I've heard, some European power companies get all bent out of shape about this.
While drawing 208v (one leg of a 3-phase circuit) for EV charging in the USA is done fairly regularly, I haven't heard a lot of complaining about it yet.

208V would be two legs of a 120/208 circuit, but yes, your broader point is correct in that large loads on part of a multi-leg system will unbalance it. The same can happen if you put a bunch of loads on one leg of your split-phase home system.

 

[israndy]

@Earl In your first post I asked about your comment "NACS single phase will unbalance the load between the phases to a house" and your reply was "By drawing a lot of power from only one phase of a 3 phase supply. From what I've heard, some European power companies get all bent out of shape about this."

What's the one got to do with the other? The first comment is about residences, the second about business in Europe where there is no NACS. My mind is swirling

 

[Earl]

@Earl In your first post I asked about your comment "NACS single phase will unbalance the load between the phases to a house" and your reply was "By drawing a lot of power from only one phase of a 3 phase supply. From what I've heard, some European power companies get all bent out of shape about this."

What's the one got to do with the other? The first comment is about residences, the second about business in Europe where there is no NACS. My mind is swirling

No, residences in Europe often have 3-phase service. The power companies that deliver the power are the ones that get bent out of shape at the suggestion of installing high power single phase appliances, such as EVSEs.

Its a reason why Europe may never go to NACS. Their historical insistence on always being incompatible with the US would be another, of course.

 

[Earl]

208V would be two legs of a 120/208 circuit,

Yep, my mistake.

The same can happen if you put a bunch of loads on one leg of your split-phase home system.

I agree, I just haven't heard any grousing by US power companies about this like I have heard (2nd hand) about in Europe.
On the other hand, the discussions in Europe were associated with justifying why they rejected both J-1772 and NACS in favor of their own, incompatible standard.

 

[qdeathstar]

It seems to me that from the power companies perspective using two of the three phases wouldn’t matter overall because in sum all the chargers would be using all three phases since which phases are chosen for the evse would be fairly random. Perhaps it would be a problem where the transformers supply rows of houses were already marginal.

 

[eevee-fan]

All this stupidity with AC charging. AC charging is important when infrastructure is poor. It's akin to buying gasoline in glass bottles from the pharmacy. Why not just eliminate the OBC (and reduce weight/improve range) and go with DC charging all the way.

 

[qdeathstar]

All this stupidity with AC charging. AC charging is important when infrastructure is poor. It's akin to buying gasoline in glass bottles from the pharmacy. Why not just eliminate the OBC (and reduce weight/improve range) and go with DC charging all the way.

High voltage dc is very dangerous. I don’t think it is suitable for home use.

 

[eevee-fan]

High voltage dc is very dangerous. I don’t think it is suitable for home use.

Isn't 240AC also very dangerous, thus why we have 120v in the US. I guess that's why we have EVSE. DC charger is just the EVSE and the OBC combined. No DC power goes to the car until it is determined safe.

BTW, most of the world runs 220v AC in the house, which is dangerous.

 

[Rocky_H]

All this stupidity with AC charging. AC charging is important when infrastructure is poor.

Uh, no. It's because AC circuits are pervasively available EVERYWHERE and the devices to use them to connect electricity to the car are extremely cheap. It doesn't take a big construction project and huge equipment to put in an AC charging device like it does with a dedicated DC charging station. Cheaper equipment means more quantity of it can be made available.

 

[eevee-fan]

Uh, no. It's because AC circuits are pervasively available EVERYWHERE and the devices to use them to connect electricity to the car are extremely cheap. It doesn't take a big construction project and huge equipment to put in an AC charging device like it does with a dedicated DC charging station. Cheaper equipment means more quantity of it can be made available.

You do know of portable DC Chargers, right?

10kW CCS CHAdeMO Portable EV Charger - SETEC POWER

The 10kW CCS CHAdeMO Portable EV Charger stands out for its portable design and is compatible with both CHAdeMO, CCS1 and CCS2.

www.setec-power.com

... so you can charge the Model 2 LFP at 10kW instead of 7.68kW.

 

[Rocky_H]

You do know of portable DC Chargers, right?

Yes, of course I do. They are stupid expensive and too heavy to be portable. I was trying to find a link to that one on EVSEAdapters, but it looks like when they revamped their site and product offerings they stopped carrying it.

 

[qdeathstar]

Isn't 240AC also very dangerous, thus why we have 120v in the US. I guess that's why we have EVSE. DC charger is just the EVSE and the OBC combined. No DC power goes to the car until it is determined safe.

BTW, most of the world runs 220v AC in the house, which is dangerous.

240v ac is dangerous, but 240v dc is more dangerous.