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Can the Twizy charge rate vary?

I have a Zappi type 2 charger installed and recently borrowed an eGolf, which was a pretty good experience.

Something I learned was the eGolf could vary it’s charge rate as communicated by the Zappi charger. So, for example, I could select the charge to be 100% green so if there was say 1kW of solar surplus the Zappy would tell the car to charge at 1kW.

When I recently replaced my Twizy charger I noticed an additional connection to the power lead.

This is connected to a pilot terminal on the charger circuit board.

My questions are:

Does anyone know what this pilot connection is for?

Does anyone know what happens to this extra wire in the power cable?

As I understand it the type 2 charging sockets have two pilot pins; one which tells the charger the vehicle is connected and another to communicate information including the charge rate.

It would be great if the Twizy charge rate could be controlled this way as it’s not often we have the full 2kW of solar surplus.

Alternatively if the charge rate could be reduced manually somehow, that would be useful.

Any information would be much appreciated.

Bump.

I’ve been reading up on OVMS (as I am one of those geeks who really does like to tinker and read up about things before buying anything) and found that you can change the charge rate via an OVMS dongle. See page 17 of this PDF:

In this document it says you can choose the charge rate as follows:
1 = 1.6 A / 400 W
2 = 3.1 A / 700 W
3 = 4.7 A / 1,050 W
4 = 6.3 A / 1,400 W
5 = 7.8 A / 1,750 W
6 = 9.4 A / 2,100 W
7 = 10 A / 2,230 W

Now, that alone is probably not much use to you if you own a Zappi as it wants to sense what’s going on using it’s CT clamps and then send a pilot signal to the car. But its certainly a start. I don’t know if there’s an app you use with Zappi and if it has an API you can talk to programming wise. Not done much research on the Zappi as I’ve been eyeing up an EmonEVSE charger as my planned Type 2 socket one day.

The official standard for Type 2 pilot wire signalling is based on J1772 standard, a 1kHz square wave generated by the EVSE charge point on the wall, with a varying mark-space ratio to signal to the car the maximum charge current allowed. The standard starts off at 6A and increases up to 32A for domestic chargers. See
https://openev.freshdesk.com/support/solutions/articles/6000052070-theory-of-operation for more geeky info.

I have no idea if that pilot connection on the charger board works using a 1khz square wave signal or if it’s some other system. I have my doubts that it is the proper standard J1772 pilot. J1772 starts at 6A, the Twizy can go as low as 1.6A. Either someone needs to get their hands on a charger to reverse engineer it, or find documentation on the charger module (good luck!) or be ballsy enough to experiment. If it were me, the starting point would first photograph both sides of the PCB to get an idea what that Pilot connection is going to. A bit of research is always a good start. Unless you’ve got the test kit and the experience of working with mains voltages, I would not go any further down this rabbit hole.

There are a few guys out there who enjoy working on this sort of stuff and have vastly more experience than myself. Mike is one example:

I wonder if he ever frequents this forum?

1 Like

Wow, there’s lots of information in the OVMS document!

I already have a Delphi diagnostic lead although haven’t yet found a way to change the charge rate using that. I don’t think it’s quite as versatile as the VCDS system I have for my Audi with which you can change many settings.

I also have a PowerBox BT, which already has a setting to end charge (eg. at 90%) so maybe a charge rate setting is something Kenneth could include on that.

Thanks for the information.

:slight_smile: