Our strong advice is not to leave the dongle active in the car while you’re away. In essence, it is a not-secure direct access device to the main CANbus of the car, with a default Bluetooth password. I have been able to wake up all the ECU’s from a sleeping Zoe using just the dongle. Things like opening doors are probably pretty hard to do but I wouldn’t consider it wise to believe it is impossible. That is one more reason we like the Konnwei – Maxiscans: they have this little on/off button on the top (unfortunately, they do not seem to go to sleep after half an hour of CANbus silence as the documentation suggests, but alas). At least it is easy to switch it off.

Another side of the question is power usage. I am bringing this up as my Zoe was completely and utterly dead this morning with a flat 12 volt battery. So, I decided to check how power hungry my dongle is: less than 1 mA when off, 40 mA when on with a sleeping CANbus, so that should drain the battery of not more than 1 Ah per day and should not be an issue.

Bottom line: be smart and switch it off. If not, and she’s still there where you left her, no harm done.

PS: It was really odd as the car was connected to the charger (had not charged for one reason or another), but the traction battery was still at least half full. My charging logging email from Renault suggested that she had her last charge in the night from December 30th to 31st. That could be right, as there was virtually no driving last week but last night definitely is strange. I have a suspicion about what happened but before I am sharing that I need to get rid of the error and ensure the 12 volt battery is not a dud.

Update: I had her up and running again after charging the 12 volt battery enough (a few hours on 3A) to wake her up and start charging. Never ever do this with the car connected. Remove the minus lead and, as the car can decide to try to charge the battery even with the contact off, make sure the lead is isolated. My suspicion is that the charger plug was not seated correctly and it tried locking it for a couple of hours with most of the ECU’s awakened by the dashboard computer. After charging there was a message to check the electrical system, but that went away by itself.

image22One of the new features in version 1.09 is the possibility to collect a time based graph of the charging process. It shows the development of the battery’s energy level, but also the maximum power level the charger is prepared to supply. If the charger is load balancing will show up in this graph. Furthermore, it is very clear how the car, while the SOC goes up, caps the maximum power that can go into the batteries, until it reaches the actual power level of the charger.

In the example here you can see the charger being prepared to supply 31 A over three phases (20 kW), and the car being prepared to take 43kW, but that last number going down as the SOC is going up. It starts capping at roughly 8 kWh in the battery, suggesting a battery temperature of about 12 C and then goes down until it reaches the charger’s power level of 20 kW at around 16 kWh SOC. If you look carefully, you can see the actual DC power following the capping in the last few minutes. The charge was ended there as charging speed bled off and putting in that last 5kWh would have taken excessive time.

The “blips” in the maximum power level we believe is caused by the temperature of the battery pack going up. It is measured with a resolution of 1 degree Celsius, which would explain the choppy line.

You can find these graphs under the Technical menu.

Most of you know the situation. For one reason or the other, you end up with the dreaded RNOD (Red Nose Of Death) and the dash indicates “Battery Charging Impossible”. Worst case that can leave you stranded, and best case you end up with a disabled cruise control / speed limiter and a that blinding orange light in your face. In most cases this is caused by a grounding fault, and these are often edge cases. The natural response is to simply try again and sometimes this works, but very often it doesn’t.

Unfortunately, the CC/SL will only return after a successful charge, however short. There is not much we can do there (maybe reset the BCB or LBC through CanZE, I never tried).

There are two things that you really need to know, however strange they might sound.

First, remove the charger cable, lock up the car and wait until the car completely powers down. You can sit in the car if you want. Pay attention to the power down sequence. After about 3 minutes, you will hear a soft click and the little LED in the lock button on the top side of the R-Link will go off, as will the auxiliary power. Then, after about another minute or two, you will hear a second, soft relay click. Then, wait another minute. Then CANbus will go to sleep, but there is no indication for that, just wait out that minute. Don’t touch a thing during this wait. Of course you can simply walk away and time a minimum of 6 minutes, but the key is: no cable, everything locked. After this, the computers, and possibly a few big capacitors in the BCB will be in a cleaner state and charging will often be possible. If there is no real grounding problem, you should be able to start the charger normally. I should stress that simply driving to another charger and not going through this “rain dance” usually does not solve the problem.

Second, in some rare edge cases after above procedure, everything will seem to be fine, no errors, but still, the charging process itself will just not start. In the rare cases I had this, I had walked away and retried without opening up the car. Just opened it’s nose, connected the cable, activated the charger. If this happens, unlock the doors. This will wake up all computers, the dash, etc, and that usually makes it realize that indeed it should be charging. The reassuring “clunk” from the charger and the “click – wheeeeeee” noises from under the bonnet will hopefully make you breathe again.

Another problem might be that by accident a scheduled charge is set. So, if the car refuses to charge, look for that little clock icon in the top row of the dash display.

Finally, as was mentioned in one of the comments, a long press on the start button may help, but I cannot confirm this.

We are very close to releasing 1.09, probably today, and we are pretty excited about it. We have revamped the consumption screen substantially and we really believe you will like it a lot, especially if driving economically is your thing.

Screenshot_2015-12-29-13-49-59Let me give you a small run down:

  • The Torque (Nm) bar from the driving screen, including the Blue Aiming Bar has been added to this screen. This will aid in avoiding friction braking (short term behaviour).
  • The tiny consumption (kW/100km) dial has been replaced by a fat bar. This will aid in being a bit more gentle on the accelerator (short term behaviour).
  • The first timed graph will show you the last couple of minutes (this depends on the screen-width of your device) of power usage and energy in the battery (long term behaviour).
  • The middle timed graph shows Speed and consumption (long term behaviour)
  • Finally, the last graph shows both the available distance as well as the SOC (we don’t want to start a war about what’s best, so we show both)

The short term behaviour bars assist in providing immediate feedback and feed forward. Avoid friction braking and decrease energy usage when driving and accelerating.

The long term behaviour graphs will give you nice feedback on how you drove that last part. It is very insightful how much that funny blast-off of your kitty-Zoe next to that ICE really cost.

In the technical part there is new screen “Charging Graphs” that will show you the technical behaviour while charging. You can record load balancing by the charger, where the power is limited, etcetera.

Other than that, of course the usual bug fixes, performance shaving, improvements on the graphs, etcetera. All in all there are more than 40 changes recorded.

We do our best to make things as intuitive and clear as possible, but sometimes that doesn’t work, or the idea presented simply needs some explanation. The blue aiming bar shown in the driving and braking screens, and soon to be released in the consumption screen too, might be one of those. So, here goes……

The Aiming Bar is always displayed under a Braking Torque bar. Braking Torque is the force of braking. It does not correspond to power, as power is proportional to torque multiplied by speed. In most cars, Braking Torque corresponds to the position of the braking pedal. For the Zoe, this is almost true. Lifting your foot from the accelerator pedal already induces a bit of Braking Torque. Pressing the braking pedal increases that torque.

The Blue Aiming Bar is the maximum braking torque the car can apply using only regeneration. Ideally, you should never brake more than the blue bar indicates: every braking beyond the Blue Aiming Bar is applied through friction braking and the corresponding energy is lost. As I explained earlier, the Blue Aiming Bar is a bit counter-intuitive: at very low speed, the motor cannot regenerate so the bar disappears. At high speed, even a little bit of torque will make the regeneration hit the maximum charging limit of the battery. When the battery is full, there is almost no regeneration at all.

For that reason, avoiding friction braking requires a bit of getting used to. It feels unnatural to “feather-brake” at speed and then apply more and more while speed bleeds off, and it certainly needs stricter anticipation.

Note: this does not apply to the Fluence and the Kangoo, as these cars only use the accelerator to control regeneration. Using the braking pedal applies friction braking only.

Video blogger Alloam, in his latest “Living with my Renault Zoe” episode mentioned something very interesting. A Renault battery engineer basically told him the extra capacity is added most of all because the LiPo’s have a fairly rapidly decreasing capacity (SOH) in their early life. With the extra headroom, they have been able to accomplish two things (at the cost of that headroom no less!):

  • The customer doesn’t experience that rapid capacity decrease in early life. To me that is an argument that is slightly in the “to avoid complaints about customer service, we will not be providing customer service any more” category, but I do see their point. You want to avoid customers complaints about that, especially in early life. But……
  • By not using that headroom, the overall SOH curve is higher than when using it all. That is no surprise really. It is no secret that topping a LiPo to the rim does stress it quite a bit. It was interesting to see the effect in a graph, even while it was unit-less.

Also the cumulative SOH of all Zoe’s graph is quite revealing. Dig in at 08:30

Edit: I had not read the link to the original presentation by Masoto Uriguchi.

With a bit of trouble, it doable to add points of interest to R-Link. In this country, R-Link (Tomtom) while not a bad navigation system at all, is not very pretty usable for the charger networks. User MartijnEV maintains a separate multi-sourced KML with only and all the 22 and 43 kW chargers in the country. It sits happily in Google’s My Maps and downloaded for offline usage in Maps.me on my phone.

Things snapped together as Jana Höffner described the procedure (in German) to put OV2 files in your R-Link and Pieter, who also made CanZE’s icon, found a snappy website to convert KML straight into Tomtom’s OV2 format.

Follow the links to get the gist of it. MartijnEV decided to publish the ov2 files in parallel with the KML. Instructions, with alle relevant links open when you click that yellow PC alike symbol in the far North of the map.

Edit: More generic instructions (in German) can be found in the goeingelectric wiki, including those for Linux.

There are many misconceptions about fast charging. One being that “the battery should be as cold as possible when fast charging”. I mean, when hooking up the battery to a fast charger, all these fans start to run right? So it must be true. Like so many assumptions, unfortunately it isn’t. Zoe’s Batteries are very, very happy when they are over 25C and actually, when they are colder than that, the BMS will rightfully cap the maximum charging power. 43kW fast charging a pack that has been freezing overnight to 0C would almost certainly damage it beyond recovery.

Having said that, overheating the cells, that will still happily charge at a temperature of over 40C **), is a very, very bad idea. Renault implemented a pretty clever solution for that, installing an extra evaporator of the climate system in the air inlet of  the battery compartment, which is why you not only hear the battery fans kicking in, but also the climate control when fast charging.

Which of course leaves the question, why would the car do that when fast charging and the cells are way below that happy temperature of 25C and higher? Well, consider that about 10% of the energy is lost to heat *) when fast charging the battery, that is over 4kW of heat being generated, which is substantial. The car is simply using a pre-emptive strategy, blowing cooled air over the batteries. If that annoys you (those fans can really “take off”), simply put the car in ECO mode before powering it down. The climate system will not kick in now kick in at a much higher temperature. And of course, the batteries will heat up faster. Which might or might not be a good idea really. Some chargers do not appreciate the interruption of the charging process and ECO mode might avoid it.

*) some say full cycle energy loss in LiPo is 3%. While that can be true under ideal circumstances, 43kW (2C strategy) is not that.

**) Masoto Uriguchi, battery engineer at Renault states the batteries are happy up to 60C, but should not be taken above that.

“Granny charging” is used for ultra slow, normal plug charging. So it’s not about charging up grandma, but charging AT grandma’s place, if she lives just a tad over half the range away and no decent public chargers on the way, read: emergency charging.

And there is another reason why I keep it in the trunk: I have had occasions where a flaky grounded charger put my Zoe in the “red nose” mode. I’ll talk about the reset procedure in another post, giving me back my precious cruise control, but one part is: a successful charging session, however short.

Here are two video’s of my home-build. It cost me roughly 150 Euro’s. A “real”, clunky one could easily set you back 400 Euro’s and Renault retails (retailed?) theirs here for more than 700 Euro’s.




For the technicians: no, this is NOT a fake system that simply puts the proper pilot signal on the CP pin. It is a decent OpenEVSE system, doing all the checks and balances.

LED schematic (thanks to user “seti”)



I took the liberty of posting a picture of a rebuild that reader “seti” made, see the comment thread below.

Granny Cable1

And another one by Andy Fraser.

Thank you all for rebuilding!

OK, maybe I am a non-friction-braking junkie.

Today, I had a discussion with a friend who owns a Tesla model S. The single motor type, but with the complete performance pack. As we started to talk about braking, we figured the S’s stategy is quite different than on the Zoe and is actually closer to the Fluence and Kangoo. In simple terms, on the S, touching the braking pedal does friction braking, period. Regeneration is applied through not, or barely touching the accelerator. He calls this “one foot driving”.

He also told me the “average” tesla driver doesn’t do any aiming-braking. With that I mean unpowered coasting, letting the motor basically run free. It seems to be popular with Fluence hyperdrivers to avoid the regen-use cycle.  I have to assume this is because hyperdriving is less of an issue with a 80kW battery.

The regenerative braking strategy itself is different too. The Zoe seems to aim at fixed torque, mimicking a traditional car. It is transparent to the driver if that torque is generated through regeneration or friction braking. The S seems to aim at a fixed regeneration power level (up to 60kW, which is lower than the Zoe per kg). As I explained in the previous post, that means increasing torque as the speed bleeds off. When the car reaches roughly 50km/h it seems to switch to constant torque, probably as otherwise the braking would get too brisk and uncomfortable. It is an interesting approach (irrespective to whether it is controlled through a braking pedal or not) as it is the behaviour I am trying to mimic through following the blue bar in the driving screen.