Charging works on CCS2 Tesla V2 but not V3

[Turk]

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

I am thinking of potential issues with the fix in the car.

If you use a separate external battery. Say for example you use a small 9v battery then regulator then resistor in parallel with Pp and Pe pins. While the battery is healthy you have 5v from the regulator and all is good. Lets say the battery discharges and drops below 5v. At some stage the car is going to see that the Pp voltage is less than 5v and think there is a charge plug connected. If you are stopped the car wont start. Who knows what the car will do if you are already moving!

You can put in a switch and only switch this in when you charge at a Tesla SC. As long as you remember to turn it off. I believe the "official BYD fix" gets the 5V from the domain controller so you could do this.

However you will still need to be able to switch out the fix for ac charging as this is controlled by the Pp Pe voltage. This is the associated software fix that BYD does as there fix is permanent.

You don't have this issue with the external adaptor. Once charged you pull the thing out and the car is in its original state. It also avoids removing the front wheel, arch cover to access the back of the charging port to insert a fix. And potential warranty issues changing the car wiring. The external adaptor obviously costs more ($AUD300) for me.

I'm still not sure why BYD doesn't go for the external adaptor. Mass produced in China for $200. No need to pay expensive western prices for labour. The harness is not free to them either. I believe Tesla Terms of use allow external manufacturers adaptors (at least in the States).

[sstanleyau]

believe the "official BYD fix" gets the 5V from the domain controller

FWIW, looking at the service documents it appears that the official fix disconnects PP from where it is now and connects it to the PP equivalent on the on-board charger. Quoting from the document:

the problem can be effectively solved by installing a low-voltage wire harness and connecting the CC2 detection pin reserved by PDC to the OBC CC detection circuit

[sstanleyau]

Three months later and no change in status, and I thought I'd revisit this topic. In particular, I'm interested in the part where the prototype uses an Arduino to monitor the PP-PE voltage at the car end of things so it can disconnect the PP signal at the charger end. I guess I have two questions:

How necessary is this?

How would it be done with a comparator?

If the answer to the first is not very, it greatly simplify things. I could use a cheap 5V power supply, and remove the need to make any sort of PCB -- the voltage divider resistors could even be mounted in the socket. If it's not, I'm a bit lost

Appreciate any thoughts.

[uhi22]

I see no problem in mounting a 1k5 resistor on vehicle side, and a 330ohm at 5V on charger side. Maybe there is a timing supervision of PP and CP on charger or car side, but I would hope that if you plug everything together within a few seconds it should work.

[sstanleyau]

I see no problem in mounting a 1k5 resistor on vehicle side, and a 330ohm at 5V on charger side.

Thanks. There's already a 1k5 in the car-side socket, so if the extra checking circuit is going to be skipped, that resistor can just be left there. Makes it all very simple.

[JustCharging]

I've been keeping an eye on this topic on and off for a while, and after recent posts I decided to bite the bullet. I'd like to thank all the posters.

Anyway, tonight I found out two things:

* The adaptors and other bits I ordered have arrived in the local courier depot and are out for delivery. Whee!

* It looks like BYD might finally be going to do something: https://zecar.com/reviews/byd-australia ... ity-issues

Coincidence? Karma? Whatever, I'll take it.

[JustCharging]

So I took my adaptor for a quick test this afternoon, and it worked fine. My SoC was fairly high so it was a short and slow session, but there were no real problems.

A couple of things for anyone else looking to go down this route...

I didn't open the CCS1 to CCS2 adaptor. I started, but it's full of stuff like Turk's, so I just used it as is after confirming it had the 1K5 resistor.

I used a slightly different CCS2 to CCS1 adaptor (EVqiaoyi) -- it's a bit more compact and it also has a cowl over the CCS2 socket, so you could cobble together some locking mechanism if you wanted. It also has a switch on the side that it claims makes it compatible with more cars, but turns out just to connect the PP pins on both sides of the adaptor.

I toyed with re-using the switch, but it was where I wanted to mount the power box, so I just used the hole to pass the wires through. I put a double-pole switch on the power box that switches off the battery and disconnects PP.

For power, I'm using a cheap adjustable LM317 unit, setting it at 5 volts and running a 330R pull-up resistor as uhi22 suggested. It fits nicely with the battery in a small waterproof box.

This is a backup device for me -- I don't usually need to use Tesla chargers, but it's nice to know I now can if it makes more sense.

Thanks to all here.

[Turk]

That looks like a really neat solution "just charging". Makes my version look very hacky with the control box held on by velcro with wires from the adaptor about a meter long and just hanging. They were that long on purpose so that I could sit in the car and debug things if necessary. As it was it just worked.

The couple of times I have used my adaptor at up to 89 KW there was no discernable increase in temperature. The standard rating of 250A for these adaptors is less than what the Atto3 can draw.

re: "sstanleyau" question about the need to monitor the PP line on the car.

Here are some thoughts.

The CCS2 -> CCS1 adaptor I pulled apart had 2 separate circuits for the PP lines at both end of the adaptor.

I read somewhere for some adaptor that you had to plug it into the car first and then plug the charger into the car. If you plug the charger in first then the charger thinks it is connected and starts polling the CP line but nothing is coming back. Worst that will happen is it times out. Simply start again and plug in adaptor first.

If you pull out the adaptor while charging then if PP or CP line is lost then charging needs to cease asap. However as the CP is shorter it is physically impossible to lose the PP line before the CP line.

I overthought this bit when building the prototype. I wouldn't have bothered a second time around.

You asked about my circuit which adds in this extra check using a comparator etc. Let me know if you still want to look at it and I can post it.

I also have some spare PCB's I built (minimum order of 5) if anyone wants one. You can bypass the extra check bits with a link. DM me with an address (in Australia) and I can post some out.

[JustCharging]

Makes my version look very hacky with the control box held on by velcro with wires from the adaptor about a meter long and just hanging. They were that long on purpose so that I could sit in the car and debug things if necessary.

I was originally going to do something similar, but decided you'd already done the debugging for me:-) Thank you!

[sstanleyau]

You asked about my circuit which adds in this extra check using a comparator etc. Let me know if you still want to look at it and I can post it.

Yes, please!

[Turk]

Yes, please!

Here is my circuit that only enables the PP line on the charger side when adaptor is plugged in and on. As I mentioned before it is simpler to simply remember to plug the adaptor in first and then plug in the charger and leave out all this additional checking.

[sstanleyau]

There's an interesting post on Whirlpool where someone has followed up this thread and built an adaptor using just a cr2032 battery and a single resistor:

https://forums.whirlpool.net.au/archive ... #r75891654

Very simple, and fits inside.