Why does NACS adapter not work with L2 Chargers?

[Joe Hoffman]

Anyone know why NACS adapter does not work on L2 Tesla chargers?
I've tried it with Tesla destination chargers and with friends home chargers.
Both result in a message on the Rivian dashboard indicating it's not supported with this charger.

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[Osyras]

l1/l2 are AC, l3 are DC. The adapter is for dc only

https://www.power-sonic.com/blog/levels-of-ev-charging/

 

[Dark-Fx]

For one, it doesn't even have the AC pins on the CCS side.

 

[SANZC02]

Anyone know why NACS adapter does not work on L2 Tesla chargers?
I've tried it with Tesla destination chargers and with friends home chargers.
Both result in a message on the Rivian dashboard indicating it's not supported with this charger.

NACS adapter NACS to CCS DCFC only, for L2 charging you need a J3400 to J1772 AC adapter. There are several of them on Amazon or you could go to Tesla, A2Z, or Lectron sites for suitable quality options.

 

[Joe Hoffman]

Thanks Bob. Good to confirm I'm not crazy. But I'm still digging to understand why. All the pinouts seem to exist in the Rivian supplied adapter. I took another look at the adapter pinouts.
Dark-fx is right, the AC pins don't exist. That'll answer it for me.
Thanks guys.

 

[Nixapatfan]

Wasn't designed for L2 charging no pins for it. Why probably because the Tesla side shares pins for both AC and DC so can't have 1 adapter that can do both as it would feed the wrong current to one set of pins on the J1772/ccs side.

 

[Zoidz]

The pin outs exists because communication takes place on specific pins in the L2 pin out, regardless of L2 (AC) or L3 (DC) Charging.

 

[Nixapatfan]

The pin outs exists because communication takes place on specific pins in the L2 pin out, regardless of L2 (AC) or L3 (DC) Charging.

Check again the ac pins are not there just the data pin

 

[Zoidz]

Check again the ac pins are not there just the data pin

I didn't say the AC pins were there.
I said the comms take place on specific pins, regardless of L2 or L3 charging.

 

[solaskaze]

I didn't say the AC pins were there.
I said the comms take place on specific pins, regardless of L2 or L3 charging.

You'd be surprised how much comm is in there.
For example, here is the conversation between my Tesla Universal Charger and my Rivian every night:

1) Tesla Universal Charger (UC) Here, please state you type of vehicle
2) R1T -- about to charge 48 Amps
3) UC: Like hell you are, what kind of vehicle are you?
4) RIT: no charge, failing connection...
5) UC: Of FFS, OK, let's go baby mode: I will give you 40 Amps. Do you hear me? 40 Amps. Max.
6) R1T: oh wait a minute, there's someone there saying 40 amps OK, attempting to charge
7) UC: *rolls eyes*
8) ... 40 amp charging ...

 

[sub]

Thanks Bob. Good to confirm I'm not crazy. But I'm still digging to understand why. All the pinouts seem to exist in the Rivian supplied adapter. I took another look at the adapter pinouts.
Dark-fx is right, the AC pins don't exist. That'll answer it for me.
Thanks guys.

Yes, the lack of a connection makes pretty obvious that it isn't going to work. The less obvious part is why did they design it that way without the AC pins connected?

Tesla uses one set of pins for both AC and DC. The Tesla charger tells the Tesla car if it is offering AC or DC and the car then moves some physical switches in the car to either connect the charge port pins to the AC - DC converter or directly to the battery depending on what the charger is offering.

CCS cars don't have those switches. CCS uses separate pins for AC and DC. The car requires AC to be on the AC pins and DC to be on the DC pins. So how would you build an adapter that worked for both AC and DC? If the adapter is built with the input connected to only the AC pins it can't possibly work on DC and if only connected to the DC pins it can't work on AC. And If the adapter connects to both sets at the same time it is never going to work (but you would get a nice fireworks display when parts that are expecting 240v AC are exposed to 400V DC).

Since CCS cars don't have the hardware required to accept both AC and DC on the same pins an adapter that was going to work on both would have to have a computer in it that could talk to the charger to figure out if it is an AC charger or a DC charger. Then the adapter would have to have motors in it that could move switches in the adapter so it could connect the input to the correct output.

There is no technical reason you couldn't build such an adapter but switches that can handle 700 amps and 400 volts are not small or cheap. Motors that can move those switches are not small or cheap. Computers that can talk to the charger are not cheap.

So yes you could do it but it would probably be more than 10x bigger and cost more than 10x as much.

It is so much easier (for everyone) to just have 2 adapters.

 

[ElGuano]

YouTube is chock full of video reviews showing supercharging and destination charging not working because people fail to understand it. And honestly, I can’t blame anyone for it. NACS is a single connector with intelligent switching, and it’s not intuitive at all that you’d need separate adapters for AC and DC.

Gotta hand it to Tesla, they looked at the US single phase system and DC requirements, and really came up with an elegant solution.

 

[gultin]

I find it amazing that the CCS port monstrosity even made it into the wild to this extent. NACS is so far advanced in terms of compactness and ease of use. Hate Tesla as much as you want, but I'll give it to them hands down for sticking to their guns on NACS and not giving in to CCS during their early days.

 

[Polar]

You’re lucky you haven’t damaged anything at this point trying to feed possibly AC into your DC pins.

 

[Zoidz]

You'd be surprised how much comm is in there.
For example, here is the conversation between my Tesla Universal Charger and my Rivian every night:

1) Tesla Universal Charger (UC) Here, please state you type of vehicle
2) R1T -- about to charge 48 Amps
3) UC: Like hell you are, what kind of vehicle are you?
4) RIT: no charge, failing connection...
5) UC: Of FFS, OK, let's go baby mode: I will give you 40 Amps. Do you hear me? 40 Amps. Max.
6) R1T: oh wait a minute, there's someone there saying 40 amps OK, attempting to charge
7) UC: *rolls eyes*
8) ... 40 amp charging ...

The Tesla Superchargers that have not been authorized for Rivian charging respond:
3) I'm sorry Dave, I'm afraid I can't do that.

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