Blog: zoe1

Renault Zoe R240: Range test and Battery health

Today the Renault Zoe R240 went out to the Swiss consumer magazine Ktipp for an external range and battery health test and it will stay with them for the next couple of days.

Purpose of the test is an article in the magazine on what to expect when buying an used electric car, and the different possibilities to test the battery beforehand, also outside of the official Renault network.

The Renault R240 has been chosen as it has quite a substantial mileage of about 150'000 kilometers on the clock, all cars in the test will have similar mileage to compare the results.

I can already tell with some confidence that the results will be surprisingly positive: My own diagnostics on this 2015 Renault Zoe R240 suggest a State of Health of about 90% and no noticeable drop in range since new.

The car will be back for the weekend, and I will of course let you know when the article will be published. Maybe I'll even be allowed to share the findings here with you!

Renault Zoe R240 motor for the Renault Fuego?

Let's have a quick and exclusive look at the Renault Zoe R240 motor. This - in theory - would be a perfect candidate for the conversion of the Renault Fuego. Sharing a bit of history with the Renault family, with similar power and dimensions (length) like the original Fuego engine, it would have been a pretty good match.

Unfortunately, I have tried to look a bit closer into this motor, but I couldn't get any further.

With three lines and a neutral, it looks like the motor is Y-wired whereas most usual 3 phase motors are delta-wired. I think this is due to the fact that Renault used the motor as a part of the Chamaeleon charging system which allowed charging up to 43 kW (!!) on the Continental model and 22 kW on this R240 Renault inhouse unit without water cooling using the stator windings as part of the charging circuit - presumably as a transformer for charging from an AC source. This might be the reason for the unusual stator winding (with a neutral). Remember that all other EV's (including premium cars like Tesla) only offer charging up to 11kW as they are working with a separate, dedicated charger.

The problem for me with this motor now is that due to its powered rotor and wye-wired stator the only practical way to drive this motor currently is the OEM inverter-controller. It wouldn't respond to any other standard industrial or automotive inverter. Unfortunately, the OEM Renault inverter unit is still a black box at the moment, so we have no practical way to gain control access directly to the motor as we speak. I have one of these R240 motors in storage at the moment, so in case somebody will eventually find a solution to drive these motors, I can still look into this option. If anybody out there would have more information, please get in touch with me!

The story behind the Renault Zoe project

So what happened to my Renault Zoe R240?

After only 4 years of ownership (5 years warranty - so 'no problem!' you will say) but 116'000 kilometers (100'000 km warranty - oh, wait, see the problem?) my 2015 Renault Zoe R240 suddenly stopped working with a series of error messages. I tried some of the usual tricks such as charging and then replacing the 12V battery, resetting all the error messages through OBD and so on. But nothing would help.

So I decided to call a tow truck and bring the vehicle into the Renault main dealer.

The Renault dealer ran a few diagnostics and saw a failure either in the Inverter or DC/DC-Converter unit. Problem is: These units don't get repaired, but replaced by the whole power electronics unit. And as they are hard-coded to the vehicle VIN, a new unit needs to be manufactured in France, coded to the vehicle and then replaced on the vehicle. The whole operation would cost nearly 8'000 EUR, which was considered a complete write-off.

I wasn't OK with that as I bought the car for environmental reasons in a first place, so scrapping a car after only 4 years wouldn't have been a solution. But investing 8'000 EUR wouldn't really be an option either, as at the time the second series Zoe model had just been released and the residual value of the first series Zoe therefore dropped anyway. So I had to find a different solution.

With the help of the community in different groups and forums I developed the plan to source replacement parts from a crashed vehicle, and then try to carry over the chip that holds the VIN on the failed unit of my vehicle to the replacement unit of the crashed vehicle. It was a risky plan but worth a try. I could only learn a lot, but not loose much.

So eventually I found a crashed vehicle in Norway that was pretty identical to mine, and a guy in Kent, United Kingdom that was willing to try the transplant. My original plan was of course to go to Kent myself, but then Corona came. I had to change my plans and manage everything from home. So the first step was to disassemble my vehicle to free the whole drive unit. You can see in the video further below how that went. Pretty fine, actually.

The most difficult part was to remove the gas in the cooling system, which is R1234yf, a gas that was kind of new at the time and most independent garages wouldn't have the right equipment to discharge the system. But luckily some small B-dealer of a German brand in my neighboujust got delivery of a new system and accepted to try it on my Zoe, knowing that it wouldn't be a huge loss if something unpredicted would happen. So kind of a win-win situation. The rest of the disassembly went pretty smooth as you can see in the video in the post below.

The standard time for the disassembly as per the Renault workshop manual was somewhere around 8 hours, and I managed to stay pretty close within that timeframe.

So in the end the drive unit, consisting of motor, inverter and DC-DC converter, was free and ready to be shipped to the UK. Here's the moment when I loaded the unit on a Pallet for crating

and here's the finished crate, ready to be shipped to Kent, UK.

Hang on to see how the story went on!

Disassembly of the Renault Zoe R240 in 60 seconds

In this video you can watch me disassemble the whole drive unit of a 2015 Renault Zoe R240. After removing the front with the spoiler, headlights, radiator, cooling system etc. and disconnecting the battery, we can remove the inverter, dc-dc-converter, motor and some accessories as a unit. Quite a bit of work!