CHAdeMO adapter wait frustration

[wk057]

NEC doesn't apply to appliances, only infrastructure. An appliance designed for 50A can draw 50A, continuous or not.

This seems like a debate for another time. The NEC may not have jurisdiction over appliances depending on where you are, but it certainly has guidelines for construction and such of some specific appliances, like EVSEs, that it definitely makes sense to adhere to. Keeping in mind that the NEC is put out by the NFPA (National Fire Protection Association) I tend not to argue too much with them.

With regard to the continuous load provisions, the technicality behind it is that supply equipment is not actually "derated", but rather circuit conductors and OCPD's must be sized for 125% of the offered continuous load. This means you start with the load (40A or 80A) and then size conductors and OCPD's at 50A/100A, not the other way around. It may seem like the same thing, but it makes a difference when it comes to calculations like applying derating factors and such.

You are correct. I'll be more careful with interchanging those terms in the future.

Never-the-less, it would be my hope that Tesla would have designed the adapter with the 1.25x rule in mind.

 

[Cottonwood]

Never-the-less, it would be my hope that Tesla would have designed the adapter with the 1.25x rule in mind.

Be very careful with the 125% rule. Over Current Protection Devices (OCPDs) are required to protect the wiring, and most OCPDs are required to be rated at 125% of the continuous load. IMO, the 125% rule on OCPD's is in the code to allow economic production of OCPDs that will reliably trip at 101% current and reliably not trip at 80% of rating for a continuous load. The Relevant section of the NEC, 215.3, quoted below recognizes this and allows for OCPDs that are rated at 100% continuous load to be used as such. (Tesla uses 100% rated OCPDs in the Supercharger Distribution Center.) Therefore, I argue that there is no 125% rule for wiring, only for OCPDs.

2014 NEC - 215.3 Overcurrent Protection. Feeders shall be protected against overcurrent in accordance with the provisions of Part I of Article 240 . Where a feeder supplies continuous loads or any combination of continuous and noncontinuous loads, the rating of the overcurrent device shall not be less than the noncontinuous load plus 125 percent of the continuous load.

Exception No. 1: Where the assembly, including the overcurrent devices protecting the feeder( s), is listed for operation at 100 percent of its rating, the ampere rating of the overcurrent device shall be permitted to be not less than the sum of the continuous load plus the noncontinuous load.​

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Dual/single chargers doesn't matter, since this adapter bypasses the chargers just like a supercharger. Chademo stations are kind of like mini superchargers.

Technically 125A max would mean between about 35 and 45kW DC (max 50kW, but I don't think the car accepts 50kW when it is at the voltage needed to get 50kW at 125A...)... so, I'd estimate between ~100 and 135/mi per hour charge, depending on the battery's state of charge and the charge equipment power rating.

Or simply put, roughly double the speed of an 80A/240V HPWC and dual chargers.

Edit: These numbers are for an 85kWh battery... a 60 would get about 13% less power overall since the pack voltage is about 13% lower than an 85kWh pack.

See my post at The Power of CHAdeMO for some calculations and results.

The 125 Amp limit on an 85 will limit charging power to 45 kW to 49 kW, and charging rates for non-P85D's to between 150 and 163 rated mph. For the P85D, because the rated miles have a little more energy, that would be 144 to 157 rated mph.

I agree with the scaling for a 60. Because the 60 has a pack Voltage that is 7/8 of the 85, with a current limited source, the charging power is also 7/8 of an 85 or 12.5% less.

 

[AmpedRealtor]

I thought CHAdeMO could scale to 100kw? If so, this adapter would seem to only support rates up to 50 kW.

 

[jvonbokel]

I thought CHAdeMO could scale to 100kw? If so, this adapter would seem to only support rates up to 50 kW.

I am not an expert, but Wikipedia says 62.5kW (500V @ 125A) was specified by TEPCO for a JARI (?) DC charge connector, which appears (Wikipedia's word, not mine) to be the basis for CHAdeMO.

CHAdeMO - Wikipedia, the free encyclopedia

 

[wk057]

Be very careful with the 125% rule. Over Current Protection Devices (OCPDs) are rired to protect the wiring, and most OCPDs are required to be rated at 125% of the continuous load. IMO, the 125% rule on OCPD's is in the code to allow economic production of OCPDs that will reliably trip at 101% current and reliably not trip at 80% of rating for a continuous load. The Relevant section of the NEC, 215.3, quoted below recognizes this and allows for OCPDs that are rated at 100% continuous load to be used as such. (Tesla uses 100% rated OCPDs in the Supercharger Distribution Center.) Therefore, I argue that there is no 125% rule for wiring, only for OCPDs.

2014 NEC - 215.3 Overcurrent Protection. Feeders shall be protected against overcurrent in accordance with the provisions of Part I of Article 240 . Where a feeder supplies continuous loads or any combination of continuous and noncontinuous loads, the rating of the overcurrent device shall not be less than the noncontinuous load plus 125 percent of the continuous load.

Exception No. 1: Where the assembly, including the overcurrent devices protecting the feeder( s), is listed for operation at 100 percent of its rating, the ampere rating of the overcurrent device shall be permitted to be not less than the sum of the continuous load plus the noncontinuous load.​

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See my post at The Power of CHAdeMO for some calculations and results.

The 125 Amp limit on an 85 will limit charging power to 45 kW to 49 kW, and charging rates for non-P85D's to between 150 and 163 rated mph. For the P85D, because the rated miles have a little more energy, that would be 144 to 157 rated mph.

I agree with the scaling for a 60. Because the 60 has a pack Voltage that is 7/8 of the 85, with a current limited source, the charging power is also 7/8 of an 85 or 12.5% less.

A low SoC 85kWh pack will have a voltage in the low 300s. 125A at say 325V will only be 40kW. I've seen my pack as low at 299V. The charge taper should limit amperage below 125A as it rises past 80% or so. I doubt this will show anywhere near 49kW except maybe for a brief period near 50% SoC.

 

[AmpedRealtor]

I am not an expert, but Wikipedia says 62.5kW (500V @ 125A) was specified by TEPCO for a JARI (?) DC charge connector, which appears (Wikipedia's word, not mine) to be the basis for CHAdeMO.

CHAdeMO - Wikipedia, the free encyclopedia

You are right. I just did some research and the 100 kW CHAdeMO stations in Europe are 2 x 50 kW. When one car charges, it's maximum 50 kW. If two cars charged, maximum is 100 kW split between two cars (50 kW each).

 

[Cottonwood]

A low SoC 85kWh pack will have a voltage in the low 300s. 125A at say 325V will only be 40kW. I've seen my pack as low at 299V. The charge taper should limit amperage below 125A as it rises past 80% or so. I doubt this will show anywhere near 49kW except maybe for a brief period near 50% SoC.

At 16% state of charge, I get 360V, so that is 45 kW at 16%. At about 50% SoC, I had 380 Volts or 47.5 kW. At 73% SoC, just before the taper went to lower than 125 Amps, I was at 393 Volts or 49 kW. I don't have any recent Voltages below 16%, but even Tesla's claim of 120 kW and 400 rated mph is consistent with a Voltage of about 360 Volts and their current limit of 330 Amps. If an 85 battery Voltage is at 300 Volts, it has to be at a very low SoC.

Between 16% and 73%, slowly rising from 45kW to 49kW is not bad...after 73%, it's the Tesla Taper, anyway.

 

[wk057]

300 volts is 3.125V per cell, so not unusual for these cells. I do believe this is around the 0% mark on the gauge. (I've been as low as ~1%) 4.2 is absolute max, or 403.2V for the pack. I'm not sure where your 360V number comes from (probably supercharging?), which is 3.75V per cell... which is more on par with nominal cell voltage than 16% SoC. I suppose during the constant-current phase of the lithium ion charge cycle the pack could accept a voltage this much higher than the actual pack voltage, but I'm not 100% sure on that.

 

[stopcrazypp]

You are right. I just did some research and the 100 kW CHAdeMO stations in Europe are 2 x 50 kW. When one car charges, it's maximum 50 kW. If two cars charged, maximum is 100 kW split between two cars (50 kW each).

I believe the first "true" 100kW CHAdeMO were installed by Kia:
http://press.kia.com/eu/press/corporate/14_09_10_kia unveils fastest chargers in europe/

 

[jvonbokel]

I believe the first "true" 100kW CHAdeMO were installed by Kia:
Kia powers ahead with fastest EV chargers in Europe

Sadly, the math suggests these are still 50kW chargers. The Soul EV battery is 27kWh, so an 80% charge in 25 minutes works out to 51.84kW charge rate, or a 50kW rate would theoretically charge it 80% in just a hair under 26 minutes, so they probably rounded that down, or it's based on a slightly smaller usable capacity than 27kWh.

I noticed the picture shows a red CHAdeMO cable, and another black cable (smaller?) on the other side of the charger. I wonder what that could be.

Also I'd like to know what makes them think these are the "fastest EV chargers in Europe" when there are 100+ Tesla Supercharger locations all capable of delivering more than 100kW to an individual car.

 

[Cottonwood]

300 volts is 3.125V per cell, so not unusual for these cells. I do believe this is around the 0% mark on the gauge. (I've been as low as ~1%) 4.2 is absolute max, or 403.2V for the pack. I'm not sure where your 360V number comes from (probably supercharging?), which is 3.75V per cell... which is more on par with nominal cell voltage than 16% SoC. I suppose during the constant-current phase of the lithium ion charge cycle the pack could accept a voltage this much higher than the actual pack voltage, but I'm not 100% sure on that.

My recordings are on a Supercharger with pack Voltage as reported by the car. I'm not sure how much more accurate to get than that. The 16% SoC was 361 Volts at 305 Amps, and the 73% number was 393 Volts at 125 Amps. Also, on a Supercharger, I have at 97% SoC, I have seen 405 Volts at 35 Amps.

Because of internal cell resistance and connection resistance, it is reasonable to see lower Voltages with 125 Amps vs 305 Amps, but I would be surprised if those were more than a couple of percent or more than 7.2 Volts.

 

[stopcrazypp]

Sadly, the math suggests these are still 50kW chargers. The Soul EV battery is 27kWh, so an 80% charge in 25 minutes works out to 51.84kW charge rate, or a 50kW rate would theoretically charge it 80% in just a hair under 26 minutes, so they probably rounded that down, or it's based on a slightly smaller usable capacity than 27kWh.

This other page makes it more clear: at 100kW it takes 25 minutes, 50kW it takes 33 minutes. Kind of disappointing (might be battery limited).
http://www.kia.com/worldwide/about-kia/company/corporate-news-view.aspx?idx=718

I wonder what the difference will be for Model S on 50kW vs superchargers (or this 100kW charger).

 

[swegman]

I called Tesla to find out where I stand. I was told my name was added to the list on Nov 3, 2013 and I am number 120 on the list, with about 50 invites to purchase having been mailed out to date. However, in reviewing the past posts just now, I note that Morristhecat (post #713) said he is number 120. So I'm not certain whats going on.

 

[Mario Kadastik]

Got this nice e-mail after asking around (this is EU adapter):

The Accessory Manager confirmed that you are on the waiting position number 16 of the list. This means the delivery for your CHAdeMO adapter will most likely start next week.

 

[Saghost]

My recordings are on a Supercharger with pack Voltage as reported by the car. I'm not sure how much more accurate to get than that. The 16% SoC was 361 Volts at 305 Amps, and the 73% number was 393 Volts at 125 Amps. Also, on a Supercharger, I have at 97% SoC, I have seen 405 Volts at 35 Amps.

Because of internal cell resistance and connection resistance, it is reasonable to see lower Voltages with 125 Amps vs 305 Amps, but I would be surprised if those were more than a couple of percent or more than 7.2 Volts.

Pack Voltage? Where are you reading that?

I'm pretty sure the voltage reported on the screens during all forms of charging is the incoming charger voltage. For DCFC events, that'd be somewhat above the pack's resting voltage at the current state of charge (otherwise the pack won't be charging.) Higher charging currents imply a larger differential between the applied voltage and the current resting state...
Walter

 

[Cottonwood]

I wonder what the difference will be for Model S on 50kW vs superchargers (or this 100kW charger).

See my post at The Power of CHAdeMO.

• Tesla claims 0:40, 0% to 80% SoC on a Supercharger.
• Extrapolating, it took me 0:50 to go 0% to 80% on 2/5/15 at Silverthorne in a P85D with a slightly cold battery. The actual charge was 0:45 for 10% to 80%.
• Assuming Voltages are the same as a Supercharger with 125 Amps of charging, I calculated a charge time of 1:22 from an ideal, 50 kW, 125 Amp CHAdeMO to go 0% to 80%. The highest used power was 49 kW, just before the taper started at 393 Volts.
• That is 42 minutes longer than the Tesla claim and 32 minutes longer than my instance on a Supercharger. 73% and higher, both the Supercharger and CHAdeMO are taper limited.

As many have pointed out, this requires a CHAdeMO and adapter to keep up 125 Amps without hesitation for about 80 minutes. Still, for small, non-Tesla installs, with a reliable CHAdeMO Charger, CHAdeMO looks attractive.

 

[jvonbokel]

I was told I am number 120 on the list. However, in reviewing the past posts just now, I note that Morristhecat (post #713) said he is number 120. So I'm not certain whats going on.

It could just be that the list is shrinking as people are invited to purchase, so that two days ago when Morristhecat was #120, you were at >120, and now you've both moved up.

 

[jomo25]

I received my adapter today (nice packaging btw) and managed to test it out. Unfortunately, I could only manage to burn myself down to 55% SOC on my S60 prior to reaching the local Nissan dealer with a free-to-use ABB Chademo unit. I plugged exactly in the sequence the nice instructions that came with the adapter suggested. Worked flawlessly. I was drawing about 35kW (337V@105A) initially, and it stayed essentially between 35kW and 32kW the whole way to my set charge limit of 80% SOC. I didn't realize it had hit that limit, so i lost track of time (while talking to a Leaf-owning Nissan sales guy who was interested the Tesla). But I think it added about 52 mi in 27 min. I'm happy with that.

 

[liuping]

I received mine today as well. it's #477.

It's a quite a bit heavier than I expected.

I tested it at a a nearby ngr EVgo ABB dual CHAdeMO/CSS charger (Carlsbad Outlet Mall).

I was only down to 45% before starting (I skipped charging last night, but my commute is just not that long)

It started charging at around 32kW, but moved up and hoovered around 37-38kW fairly quickly. I Charged for a little over 20 minutes with no problems. The adapter cable was slightly warm to the touch, but not really hot.

 

[wk057]

Has anyone seen anything close to 50kW with one of these? (I'm sticking to my guns and saying it's not possible until I see or can test to the contrary....)