I’ve been busy recoding the interface between my home automation and ZE services as Renault changed their entire apps and API to “MY Renault”. That worked out with the kind help provided by James. All back on track again in Node-RED.

While doing some research I ran into a post from one of the developers on the French forum. This was one of the things he mentioned that has always been “somewhat known”, but more precisely formulated now.

  • Start of charge
  • During charging, every 30 minutes (every 15min for Z.E. 40)
  • End of charge
  • Beginning of a journey
  • During the trip, every 30 minutes (every 15min for Z.E. 40) or every 5% of SOC (state of charge of the battery)
  • End of a trip
  • Before sleep (3 min after lockout) if the battery value has changed since the last message
  • Before sleep (3 min after lockout) if the car is not connected, a charge is programmed and the charge level is less than 100%
  • Low battery alert
  • Instant pre-conditioning set point.

The Range screen has been fixed and needs some explanation. In essence it compares the available range calculated by the car to three different ranges:

  • The first number is a range based on the current energy content of the battery and the worst consumption;
  • The second number is the same, based on average consumption. One would expect this to be the same as the car reported range, but it isn’t;
  • The thirst number is the same but using the best consumption.

The consumption numbers are calculated by the car. The second number can made a bit worse using the slider to adjust for sporty driving. In my case, leaving it at -10% seems to be about right.

Quite a while ago I did a strictly theoretical calculation on ZOE’s acceleration. You can find the post here. The end result was 8.9 seconds. I think in reality it is somewhere between 11 and 13; I should really do a test for fun but I don’t have a free runway available for that.

Anyway, I did the calculations again for the R110 under the exact assumptions, and in addition assumed that the maximum power level during acceleration was 88 kW. I have no idea if this comes close.

Car starts it’s accelerates exactly like the Q210/R240/R90 models: 5.0 m/s², but the R110 hits it’s (higher) power limit a bit later (2.36 seconds) and a bit faster (11.9 m/s). The remainder of the acceleration is at full power, reaching 100km/h (27.8 m/s) after a total of 7.6 seconds, roughly 14% (1.3 seconds) quicker. That 14% is probably pretty close to the real world difference.

In the next release, which we will try to push out really soon, the Tyres screen has been augmented with a section where you can read the IDs of your TPMS valves and write them back. So, if you have a second set of wheels with TPMS valves, simply make sure you know and remember the IDs of the valves, and can write them back in after a change.

At this moment we have no way to let the car reliable learn new valves with unknown IDs, so you need to visit the dealer once more to get to the IDs of your other set of valves, but from then on, you’re done. Also, if you happen to buy after market valves, check the packaging if there is a 6 hex digit ID printed. Might save you a dealer visit.

If you have TPMS, our advice is to read out the IDs as soon as the next release is out and store a screenshot somewhere.

Thanks bjaolsen for the information and Richard for letting me try this on your car.

We might have ironed out most issues with the DIY dongle. If there are people willing to build an ESP32 based dongle, especially if they own a Q90, R90, or R110 model, we would like to hear about it. Requirements would be:

  • Preferably drive one of the above models.
  • Willing and able to build a dongle, which requires ordering stuff through Aliexpress or ebay HK, basic soldering skills, and either some basic knowledge of using PlatformIO with Atom (or VSCode) with git, or the ability to upload binaries to an ESP32 development board from the command line.
  • Fool around with it, and be willing to cycle quickly though different updates of CanZE or the ESP32 code.

This is a re-post of what I wrote on SpeakEV a few days back.

The battery in my key card had failed. Note that in the “non-keyless” version, the car does not warn you about that. I removed the mechanical key from the key card and put it in the lock. Turning it, the ring arch, acting as a lever snapped off. You can still see the original crack in the picture below. The arch is made from a hard rubbery material and it had obviously weakened over time. Glue was no option. The material is not very suited for it and anyway the levered forces on that tiny surface area would be way too high.

What I decided to do is first glue it with super glue to ensure it’s original shape. Then I used pieces of small black nylon tie rib to reinforce the arch. Using a hairdryer I bent one piece to follow the inside curve (where the key ring pulls), then glued it in with two component resin. I repeated that for the (flat) bottom part, filling up as much cavity space where I could. For extra strength I also put a third strip over the slightly curved top of the arch, diverting even more force from the original crack. I let it harden and then used a power file to grind away excess resin and sharp ends of the strips. Finally, I touched it up with some black permanent marker. I expect the nylon to last forever, the metal key ring will not shave that off soon.

Bottom line is: when using the mechanical key, tread very lightly. Also, do check the integrity of the arch part of your card. If in doubt, you might want to do something about it. I did with SWMBO’s key.

Before we start two things: I made a significant error about ripple current in the previous post, corrected now. Also, we have a lot less data for three phase operation, so this post is more speculative. If you think I made significant errors, please comment. Before going on, I assume you’ve read at least the post Charger Design.

Theory: Consider the following set of graphs, the first one representing the voltage between each of the phase lines (La, Lb, Lc) and Neutral (N).

The output voltage Vdc of a three-phase full-wave rectifier as shown in that post looks like the second graph. Side note: The 0 potential in the upper graph (the N line) is very much not on the same potential as the 0 in the middle graph, which represents the minus output of the rectifier. For a 400 volt line to line system, the average Vdc will be almost 540 volt, peaking 562 and bottoming 487.

Assuming for the moment a simple resistive load on that Vdc, the input current on the wire of phase A Ila will look like the third graph. So there we have it. It looks “somewhat sinusoidal”, but there will be quite a few harmonics in that current. But we can imagine this waveform a bit smoothed out by the filter contraption of the charger.

I have exactly one voltage-current graph of a ZOE charging in 3 phase operation. It is for a Q model on an 11 kW (3 x 16 A) charger, but the battery was already quite full, so it is running on a lower current.

Looks familiar? Some phase shift and smoothing by the filter and that’s it. Just like with the single phase charging, the phase shift is noticeable because of the relatively low charge current. The dips in the middle of the tops are quite noticeable. The current can’t be shaped like the the line voltage simply because in a three-phase full-bridge rectifier, 1/3rd of the time a wire simply can’t provide current. For the remaining 2/3rd, the charger seems to simply follow the voltage curve of the raw DC output, just like it does when running in single phase mode.

A good article about rectifying 3 phases can be found here.

Only slightly related: I received power intake graphs from both a Q210 and an R240 when throttling down. It seems the Q model steps down in roughly 600 Watt steps, while the R model uses smaller 300 Watt steps.

After the startup sequence described in the previous posts it is now time to move on to the actual charging. Again, all the measurements come from SpeakEV user ElectricBeagle and tons of valuable info has come from user arg. If you want to check out the discussion that lead to all of this, here it is.

Let’s set the stage first. We assume single phase charging, the earth check has been performed, the mains has already been connected and, since it’s single phase charging, the relay between N and L3 has already closed. More about that later. Charging has started and as shown in the previous post, the current has ramped up to the desired level. The ramping is gradual, taking about one second.

The rather massive 100 uF capacitor is now creating that 6 A reactive current. It’s sole purpose seems to be to dampen the huge current spikes created by the switch mode power supply. Note that the capacitors are rated for 63 A. The worsening power factor is simply a side effect of that. However, at 16 A, the PF is already above 0.9, so no worries. Bottom line is: at decent currents, say at or above 16 A, the power factor is great and they do clever things with the switching to follow the voltage, see next picture, taken at a current setting of 30 A, with a very small resistor in the N line to measure current without phase shift.

At significantly lower power levels things worsen very quickly. For instance an off grid PV inverter would need to be very potent in coping with that reactive power. But I digress. Because what you really want to know is the effect of the switching. So let’s zoom in on the raggedness of the current curve.

What I wrote here before was way off, as arg argued in private…….An earlier picture suggests that the current coil produces roughly 1 volt peak-to-peak per 4 A wire current (RMS). That suggests a 10 kHz ripple current of just over 200 mA RMS. On a 10 A charge current that is give or take 2%. But this measurement was done with a current coil on the L wire at 16 A, while the previous picture was done with a resistor in N, at 30 A. I suspect the current coil is quite frequency dependent. Going back one picture, one-and-a half-dot ripple on a 26 dot amplitude is roughly 6%. At least ball park same.

Another interesting thing to look at is earth leakage, given the relatively high capacitance between the stator coils and the motor housing. One “blob” is a half-cycle, lasting 10 ms. The pattern is pretty symetrical, with a small (about 6 dots) peak to peak 50 Hz component, and a decent (about 15 dots) 10 Khz signal. The scale is 30mA/div. My rough estimate is that the 50 Hz component is 13 mA RMS and the 10 kHz part a bit above 30 mA RMS. Note that a consumer grade RCD will trip at 30 mA but as arg argued, it should not care too much about the higher frequencies (though old ones may!). All in all the stray capacitance to earth seems to be about 2nF. Note that the leakage current should not go significantly up with power, as it’s a capacitive coupling.

And this is the reason why ZOE sings. Ramping up the frequency further would progressively increase leak current up to the point where dedicated, uncompromised coils would be needed, adding quite a bit of weight if one would want to do 22 or 43 kW rectifying.

All in all I would say: not too bad really! The only thing I am not really sure about is what is meant with HF and EHF frequency in the leak currents the car can report. I always assumed 150 Hz (3rd harmonics) and 10 kHz (the switching frequency), but I am not 100% sure. If anyone knows or suspects more, I’d love to know.

EDIT: by now after more thinking and a few discussions, I am quite convinced HF means the 10 kHz domain and EHF means 10 kHz harmonics.

Oh and about the single phase relay. It can’t close before the chargepoint contactor is closed, because as long as it is open, the car doesn’t know if the chargepoint is single or three phase. However, assuming no contactor in the filter module (and I haven’t found any in the pictures of the filter and charging module), once power is switched on and it is single phase, the capacitor between L3 and N is idle, so it’s no problem to bridge it with a relay at that moment in time.