Version 1.11
Whoops. A nasty crash for first time users forced us to release a fix on short notice.
Teaser for version 1.10
We will release a new version today. As usual, a lot of under-the-hood things, especially reducing the footprint of the application and small speed improvements. No major changes, but you can find a detailed change list here but these are the highlights.
- Several improvements in the consumption graphs screen, including a low pass filter on the real consumption per 100 km line.
- Small changes in the logging.
- Added 12 volt reading (several drivers had flat batteries this winter) and the kilometers of the battery (if you had your battery changed) in the technical charging screen.
- Added an experimental screen with parameters about the battery-clima interaction.
Enjoy!
Resistors in charging cables
The AC charger cables have a resistor between protective earth (PE) and the proximity pin (PP) pin to indicate
- that the plug is inserted
- that the plug can therefore be locked (type 2 only)
- the gauge of the cable, and thus the maximum current
Note that the PP pins are NOT wired through the cable. The most common resistor values and also those of your standard Renault cable are 220 ohms, corresponding to 6 mm2 and 32 amps continuous, and 680 ohm, corresponding to 2.5 mm2 and 20 amps continuous. These are per strand values and the power varies given the number of phases used.
These PP-PE resistors should be installed on both ends of the cable, which I had not realized before. Yesterday I helped a friend changing his home charger from a socket type to a fixed cable type, so that he didn’t have to get the cable from the trunk every evening. The cable came pre-wired with the resistor in the plug, but it didn’t work. Only when we installed a PP-PE resistor in the charger itself, indicating the cable was inserted on that end, the charger started the process. The other side effect is that if you measure the connectivity between the PP pins on your standard Renault cable, you’ll measure a confusing 440 ohms. That’s because both ends are wired to the ground lead with 220 ohm resistors.
1500 Ω resistor – 13A cable
680 Ω resistor – 20A cable
220 Ω resistor – 32A cable
100 Ω resistor – 63A cable
Some pictures of the battery
A few pictures of the battery pack of the Zoe opened up. Enjoy!
Max battery charge and Max battery regeneration
In the Dutch Renault forum, the issue came up that the maximum regenerative power allowed is higher than what CanZE reports as the Max battery charge / regen kW power. Based on a few experiments of my own only, it seems the Zoe will allow double the reported power for regeneration, capped at 40 kW DC of course. After all, it is supposed to be a short burst and the amount of energy, by definition, has already been taken from the battery.
I would appreciate your findings. Just open CanZE on the driving screen and whenever the Max battery charge / regen kW is substantially below 20 kW, try to do a serious regenerative brake (from a high speed works best, i.e. a motorway exit) and see how far the DC Power kW (or if it refreshes too slow, the blue kW in the dash) shows please. Thank you!
Edit: based on my own testing it seems there is indeed a short over-power possible. The rough formula is max_charge_power * 1.65 + 3.5. More testing by Borut suggests this seems sustainable for either roughly 40 seconds, or until the total battery voltage reaches 390 volts (4.06 volts per cell), see the comments.
It should be possible to calculate the max regen power by taking the max_regen_torque (the blue bar in the driving and consumption screen) and multiply that by the wheel speed (in rad/sec). I might implement this in a test screen.
Traffic lights
The Zoe has a crawling mode that cannot be disabled (which is unfortunate I think, but I know others differ). It needs a bit of braking to counter this crawling when at a traffic light. When the brake pedal is pressed only a bit, the motor will still push and you’re spoiling a couple of hundred watts in the motor. So, when at a red light, either press the brake a bit firm, or switch the gear to N.
CanZE spinoff in the spirit of Open Source Software
A (former?) Twizy and current Zoe driver in Austria called “AbRiNgOi” had a Twizplay laying around. This is an open source CANbus driven small display, based on Atmel micro controller. Anyone who has ever played with Arduinos knows what I am talking about. The specific controller used is an automotive version of an ATmega with a build in CAN controller.
He reprogrammed the Twizplay using the CANbus information that we gathered and that is available in the source code of CanZE on github. We are very pleased and proud that our hard work is spinning off toward other projects, in the true spirit of Open Source. Link here.
TwizPlay is originally programmed in BASCOM (a non-Free BASIC compiler for the Atmel and 8051 processors), but “AbRiNgOi” decided to do this the proper, but hard way and redo all using Atmel Studio 7 and C++, bringing it much, much closer to the Arduino community.
Firmware (finally) on Github
I finally got to the point to upload the firmware of my ArduinoDue and Teensy, but please be warned that it does not work the way I would like it to work!
Charging the R240
The R240 is the Zoe with the new, more efficient, air-cooled motor that Renault developed in-house. There is some consensus that the battery of the R240 is exactly the same as the Q210, but given the different characteristics of the motor, and the fact that the motor coils are used by the charger (very smart design!) it is capped to charge at a rate of 22 kW maximum. A UK based Zoe driver noticed the “Max battery charge” nicely went up way above 22 kW and asked how that could be.
Today, user Crf supplied us with this CanZE graph when charging his R240 at a 43 kW charger, and I believe it confirms what we were thinking. The Zoe simply caps the incoming pilot and fakes it’s value towards the other systems involved. Notice how it reports 32A and 22 kW available power. Those numbers are both off and way too neatly rounded.
The battery itself (the LBC’s) reports it’s willingness to take the full 40 kW DC power load, and as the SOC goes up it starts it’s capping at roughly 11 kWh. Again, the little jumps we believe is caused by the temperature rising. 2 kWh per degree Celsius is ballpark right. The very rapid capping near the end is kinda interesting.
So yes, it seems like the R240 has the same battery as the Q210. The BCB is tweaked a bit to simply ignore anything above 22 kW and the rest of the car simply behaves as if a 22 kW charger is attached.