Charging works on CCS2 Tesla V2 but not V3

[Turk]

As a background I have a 2023 Atto3 which will charge on Tesla V2 supercharger but not Tesla V3. BYD indicates that they will not address the issue. I believe the MG5 in the UK had a similar issue but MG supplied a solution. Hence I am thinking of creating my own adapter. The first step is to identify the issues.

As far as I am aware there are two issues.

In Australia BYD fixed the Seal with a new harness that apparently contains a resistor. I am assuming this changes the input impedance of the control pin. Don't know if this is in series with the control pin or in parallel. Does anyone have any theories why this is necessary?

I also believe that the Tesla V3 contains a couple of extra protocols that we need to respond to. Does anyone know what the extra protocols are?

My initial thoughts for the adapter is CCS2 plugs at both ends. In the middle use an Arduino or similar. Pass through the V2 protocols. Trap any V3 specific protocols and reply accordingly. Maybe a generic reply or interrogate BMS etc.

Any thoughts or feedback is appreciated.

[johu]

We found Tesla is very picky about PP pullup:

viewtopic.php?p=66934#p66934

You would need to connect 1k5 resistor between PP and PE and measure the voltage across it then report back.

Forget the adapter idea, this is not the issue

[Turk]

Thanks for the reply I appreciate it. I'll do some research to understand the potential issue. When measuring the PP voltage do we need to be connected to the Tesla SuC or can we use an AC charger?

[uhi22]

It's much more simple. No charger at all is needed for a first test. Just stick a multimeter into your cars CCS port. Minus to the PE (the middle 6mm pin) and plus to PP (one of the 3mm pins). This should show around 5V. Now add an 1.5kohm resistor in parallel to the multimeter. The voltage should drop, to which value?

Cross-reference: Ioniq PP measurements viewtopic.php?p=66305&hilit=Ioniq#p66305

[Turk]

PP voltage on no load is 4.99 V
With 1.5K ohm resistor in parallel is 0.63 V

[uhi22]

This means the car has a 10k pull-up to 5V. The SuC V3 seems to expect something in the range of the official 330 Ohm pull-up.
The first idea would be to add an additional pull-up to a 5V source, to make the SuC happy. But this would most likely irritate the car, it would see a higher voltage and interpret this as "no plug seen". I guess some "resistance-translation" needs to be invented.

[Turk]

Thanks. It appears to be very difficult to access the back of the CCS2 plug in the car, so am thinking an external CCS2 - CCS2 converter and play with the PP line. Just need to find such a converter I can hack.

[uhi22]

Maybe the other end of the PP line (at the onboard charger or so) is better to access.

[Turk]

I would just like to confirm that the only issue is that the pull up resistor is incorrect in the Atto3. Thanks Uni22 and Johu, I appreciate the help.

Here is a quick description of my fix. As it is a relatively new car I wanted to avoid messing with the wiring so went with an external adapter. As there are no commercial ccs2-ccs2 adapters (why would there be!) I bought a CCS2->CCS1 adapter as well as a CCS1->CCS2 adapter. Connect the CCS1 ends together Modify the wiring on the PP (proximity pin) at either end. When plugged in the car still sees 0.65V but the Tesla SC sees about ~3.6 I also incorporated a check circuit so that if the PP is lost at the car it also dumps the PP at the charger.

[sstanleyau]

Is the circuit for your adaptor available? Any other plans for it?

[Turk]

Give me a couple of days and I will draw something out. However a working circuit is very simple. You need an adapter with CCS2 pinouts at either end. On the car end you simply have a 1500 ohm resistor from the PP to PE pin. So the car thinks a charger is plugged in. At the charger end you could get by with a 9v battery feeding a 5v regulator. From this I have a 330ohm resistor to the PP pin. And then a 4.7k resistor to the PE pin. You probably don't even need the 4.7k resistor. When the charger is plugged in the charger sees about 3.7v which is in the preferred range. All other pins on the adapter go straight through. So nothing really to go wrong.

However being over cautious and home built I check that the car end is about 0.65v and using an Arduino drive a relay so that the charger end drops out if you pull the adapter from the car. Probably not needed as the CP line is broken as well. I am redesigning this to just use a comparator chip and a transistor to drive the relay.

Just used some adapters CCS2-CCS1 and CCS1-CCS2 from ali-express. I think about $180 and $120 AUD. They appear well built. It is surprising there is no play at all when the CCS1 ends are joined together. Make sure they have a thermal cut-out on the cp pin. It is just another cheap electrical component. The adapter didn't even get warm when when running at 89Kw which is well under the 250 Amp rating for both parts. However you will need to pull them both apart to massage the PP line to add in the custom circuit at the charger end.

I reckon you could also use a CCS2-NACS and NACS-CCS2 combination.

A single CCS2-CCS2 adapter would be better, so if anyone knows a Chinese manufacturer who could produce one I'm interested.

And yes, BYD could have produced this 18 months ago and given them free to Seal owners, while they screwed the second class Atto owners for our hard earned dollars. Though they wouldn't have had the pleasure of what excuse do we use this month.

[sstanleyau]

if anyone knows a Chinese manufacturer who could produce one I'm interested

I've just sent you a private message about this.

And thanks for the details!

[Turk]

Here is a more detailed description of the prototype attached. If anything doesn't make sense then please ask.

[WynRyder]

This means the car has a 10k pull-up to 5V. The SuC V3 seems to expect something in the range of the official 330 Ohm pull-up.
The first idea would be to add an additional pull-up to a 5V source, to make the SuC happy. But this would most likely irritate the car, it would see a higher voltage and interpret this as "no plug seen". I guess some "resistance-translation" needs to be invented.

Sorry to go off topic a little but would you be able to guide me to where the 330 Ohm resistor is referenced?

I've done a bit of a dive into the standards but could only find an explicit reference to a 330 Ohm resistor in the sections related to CCS1 (from memory, was a couple of months back).

[uhi22]

viewtopic.php?p=66305#p66305
discusses the 330ohms. Not sure whether there is a 100 percent waterproof specification.

[dbmgreen]

Here is a more detailed description of the prototype attached. If anything doesn't make sense then please ask.

Hey, I just registered, so can't message you, but would like to have a quick discussion offline about a prototype, largely to address if you want some assistance with anything, if you want anyone else to butt in so to speak ....... given that you have done all the heavy lifting

Maybe you can message me?

Cheers,
David

[sstanleyau]

Looks like this will become academic -- perhaps it played a part in prompting some belated action:

"At BYD, we take pride in our battery technology leadership and are committed to ensuring broad charging compatibility. To address access to Tesla V3/V4 chargers and enhance charging flexibility, BYD has developed a retrofit charging harness. We expect it to arrive in Australia within the next 30 days, after which it will undergo thorough testing and validation. Once we are confident it meets our high standards, we will make it available for customers who require it.

"This will be an optional upgrade, and while we are still finalising pricing, we are working to keep the cost as low as possible. The Extended Range harness will be available first, with the Standard Range version arriving shortly after."

[Turk]

re:330 ohm resistor. Here is a screen shot of proximity circuit for CCS1 from IEC 61851-1 2010 standard. The value should be 330 +- 10%. From web address

[sstanleyau]

Would love to see the CCS2 circuit -- that would be a slam-dunk.

[Turk]

Looks like this will become academic -- perhaps it played a part in prompting some belated action:

We will probably never know what eventually forced them into some action (assuming a solution does arrive or its not just more of there BS) Probably a number of factors. "Ludicrous feed" was hinting there was a class action pending or they just got sick of peddling there BS and ran out of excuses. Maybe hundreds of people with home made adaptors was not a good look for the brand.

re: CCS2 circuit

I'm sure it is in the latest standard. Just seems a bit rude to fork out a couple of hundred dollars on the off chance it is explicitly defined.

[sstanleyau]

If anyone's interested, the dealer instructions for how to install the update have been posted on Telegram.

[DavdD]

Here is a more detailed description of the prototype attached. If anything doesn't make sense then please ask.

Thank you! I have made the adaptor and it works. I had one problem with the CCS1 to CCS2 part the Pp pin was too short to make contact with the Tesla plug. When I remade the pin 7 mm longer it then worked. I got my adaptors from Aliexpress but it is worth checking the pin lengths.

[elsamuse]

Thanks to this post, I found that MG5 and BYD atton3 also have charging problems.

[aero]

Here is a more detailed description of the prototype attached. If anything doesn't make sense then please ask.

Nice work discovering this, I saw this post mentioned on ludicrous feed tonight, not sure if it was yourself that commented or someone else. I have no faith BYD AU will supply a solution, one of our cars is the Atto3 and it was delivered in the first batch to Australia, it’s hard to believe they’ve basically turned their back on the owners that seeded their operation in Australia.

So what we need to finesse this is an adaptor that is female CCS2 on one side and Male CCS2 on the other side with some internal space for the battery and some electronics. Do I have that correct?

[uhi22]

Exactly. Or find the wire inside the car, cut it and plug the electronics in between.