Flip the Fleet Drivers’ Memo #28: Leaf Brakes, the need for battery replacement services, and the year that was

Dear collaborators,

Brake faults in Nissan 2013-2016 Leafs

A challenging investigation is now finally coming to a head around the potential brake faults in Gen 1.2 and the earliest Gen 1.3 Nissan Leafs. We first alerted Nissan and The New Zealand Transport Agency (NZTA) about five initial cases from New Zealand on 22 October 2018. When no substantive engagement was forthcoming, we published a first report on our website on 23 November (https://flipthefleet.org/2018/leaf-brakes-failures/). We also created an online brakes logbook (https://flipthefleet.org/leaf-brakes-logbook/) for people to report braking problems.

We have so far received reports of a further four cases from New Zealand of the main fault that concerns us, an apparent firmware fault where the main brake control unit (EDIB) can no longer be contacted by the other car control systems and an emergency “brake-assist” mode cuts in to allow impaired braking capacity. This back-up system appears to be assisted by the car’s Anti-lock Braking System (ABS). Unfortunately, some of the drivers reports and our own experimental trials suggest that a secondary fault sometimes appears where the ABS system does not intervene to help stop the car.

We also received a further 13 logbook reports of braking faults of a miscellaneous nature, most of which we have insufficient information to diagnose with certainty.

A full report on all this new information and a record of our attempts to have the risk assessed by NZTA and Nissan is now published at https://flipthefleet.org/2018/update-17-dec-2018-leaf-brake-faults/.

We are still waiting for answers to three basic questions:

Are the 2013-2016 Leafs safe to drive?
Are firmware remedies available to fix the problems observed here?
If a remedy exist, will it be made available at an affordable price for drivers of Leafs imported second-hand to New Zealand?

In the meantime, Nissan drivers can best help protect themselves and others by becoming fully aware of the potential for brake faults and what to do if it happens to them:

In most EDIB fault situations, slamming the brake pedal right to the floor and exerting as much force as you can muster will be the most effective way to stop the vehicle.
Ignore any loud graunching sounds and juddering of the car – they are a normal part of the brake assist mode. Unfortunately, during normal EDIB behaviour many Leafs tend to have quite touchy brakes where gentle and variable brake application may be required, so many Leaf owners may be subconsciously conditioned to never firmly apply the brakes.
Recurring faults sometimes happen in the same car, even in quite quick succession, so it is imperative that you stop and seek help immediately after the first occasion.
Regular servicing and maintaining a healthy 12V battery may also help reduce the likelihood of a fault, especially of minor types.
Never drive the car if brake warning lights appear at start-up.

If a fault happens to you, please:

Use LeafSpy Pro to scan your firmware ID codes and ‘Diagnostic Trouble Code’ screens and send them to Flip the Fleet along with a log book report.
Take your car to a service agent, preferably a certified Nissan dealer that is experienced in fixing and servicing Leafs so they can inspect and report to Nissan New Zealand.
It is best practice to record then clear all historical DTC notifications so that you can track the recent performance of your car.
Notify NZTA of the fault and repairs done by your service agent so they can monitor the risks
Stay on the case! If the fault recurs, record, notify and request help again.

It is important to keep these preliminary results in perspective. No one has been injured in New Zealand so far. Our projections suggest that somewhere between 6 and 21 new cases of the EDIB fault in the coming year. In many of the cases, impaired but perhaps sufficient braking power remains. There is no evidence of complete “catastrophic brake failure”, though in some cases your ability to stop may be greatly impaired.

NZTA and Nissan are now investigating and will advise when they have come to a conclusion.

The importance of battery replacement services: October’s one-click survey

A majority (65%) of you “strongly agree” or “agree” that securing an affordable supply of replacement batteries is the most serious need for sustaining EV uptake in New Zealand (https://flipthefleet.org/2018/1-click-survey-24/). Naturally enough, those of you driving the oldest and smallest EV models (especially Gen 1.1 Nissan Leafs and eNV200 vans) are the most concerned about battery services. Many of you pointed out that being able to replace a depleted battery is not just a matter of practicality (to restore range) and return on investment (the replacement batteries will have to be affordable if the life-time cost of an EV is to be lower than a combustion vehicle), it is also a matter of sustainability (scrapping a car just because of low battery capacity would be a travesty). Some of you called for government subsidies to replace the batteries, and concerns were expressed about relying on second-hand imports to underpin New Zealand’s EV uptake. The dilemma is that these second-hand imports are needed to meet an increasingly critical lack of supply of EVs in the New Zealand car market, and the subsidies paid to buy them in overseas countries helps make them cheaper when imported to New Zealand some years later.

The year that was

It’s been quite a roller coaster ride this past year!

There were a few lows …

Two nasty bits of news that distracted and sapped our time: the apparent rapid decline in 30 kWh Leaf battery health, and now the Leaf brakes issues. The former at least had a reasonably happy ending with Nissan bringing out the firmware fix to correct instrumentation (the battery itself seems Okay so far, https://flipthefleet.org/2018/nissan-makes-30-kwh-battery-firmware-updates-available-through-its-service-providers/).
A struggle to find funding – two large grant applications failed and so far researchers and policy makers who want access to the data have not been prepared to pay to help keep the system going. All up, about 15% of Flip the Fleet’s work has been paid for so far.

… but way more highs

The amazing commitment, knowledge and trust of the EV owners who signed-up to Flip the Fleet and contribute data each month
The number of Flip the Fleet sign-ups grew from 460 to 1,297 over the year
Scientific demonstration of the practicality of owning and operating EVs, their financial and environmental advantages – all providing counters to the naysayers
Collation of over 5,000 EV owner’s comments to 1-click survey answers to show the personal dimensions, knowledge and reasons for your EV grins – all valuable ammunition to help persuade more people to join the EV revolution
Measures of the relative importance of different strategies for selling EVs (accentuating the positive), and the barriers to making the switch (eliminating the negatives) –ways to build smarter EV uptake strategies
Development of EV Black Boxes by Exact IOT’s Vasily Levshin to monitor EVs on a minute by minute basis – around 50 EVs are hosting them to give a detailed picture of charging patterns, battery temperature, efficiency etc. We already have around 400 million data points to keep us busy!
You collectively provided over 7,000 monthly records of how your car went each month
Your results were presented in 30 talks to a variety of audiences – from the general public, to the EV curious, to the converted and to scientists and transport professionals https://flipthefleet.org/resources/presentations/

Above: Here’s a shot of the audience at one of the three Cafe Scientifique presentations we gave, in this case in October in Tauranga. There were around 190 people present, many of whom were retired scientists. Lots of them took test drives before the talk.

Your 1-click survey responses and monthly data found their way in to 11 media releases, and we have registered over 130 media mentions over that period https://flipthefleet.org/resources/media-clippings/ – we have been trying to carry your results to those who have not yet bought an EV!
ChargeNet’s NZ Tesla beating the Highlands Ferrari 3 – 0 in drag races at The Hare & The Turtle event at Cromwell!
Public outreach to break down the EV myths, for example through production of 12 Infographics
There were 114,122 page views on www.flipthefleet.org from 37,015 unique visitors during the last 12 months. That’s over 100 visitors every single day, or, a page view every 5 minutes!
Great help from Monica Peters, Hannah Gentle and Rebecca Hayter this year
Amazing collaboration between participants and our reference groups (ones who checked the media releases, others who commented on battery health and brake fault investigations) – especially Walter Larason, Donald Love, Mark Nixon and Joe Barnett
Generous support from the government’s Low Emission Vehicle Contestable Fund and the EECA team that manage it, and from the government’s Unlocking Curious Minds portfolio and the Otago Museum team that managed our grant
A huge increase in the visibility and demand for EVs throughout NZ. The nation is on its way to an efficient, affordable and low emissions transport future!

Thanks for being part of the team.

Mauri ora!

Daniel Myall, Dima Ivanov and Henrik Moller,

18 December 2018

Alan Lowe says

03/02/2019 at 2:32 am

Hello from the opposite side of the world in the UK.

Your research early in 2018 into the possibility of accelerated degradation of the Leaf’s 30kWh battery was of interest since I bought that model new in late December 2015, so it was one of the earliest in the UK. I live in the English Midlands, in a semi-rural area, with no particularly significant hills.

My journey pattern and mileage are relatively stable, so comparisons can be made across the years. I drive the car 26000 kilometre a year and I am the only driver. I have a home 7kW charger. The range of the car had been relatively stable for its first eighteen months but began to decline in the winter of 2017 and did not recover by the early summer of 2018. This prompted me to start using LeafSpy Pro on my iPhone. I spotted the BMS modification offered in the USA within days of its release and prompted my local Nissan dealer, who knew nothing of it but, after checking, saw that it had been released in the UK and made the change on my car.

That dealer had tried to turn me away with talk of natural degradation but I persisted since the loss of range had gone over 20%. At this time, I was able to measure the energy input into my battery from nearly zero indicated range to 100% on several occasions and it never reached 24kWh, even in mild weather with a battery starting at ambient temperature; this with a nominal 30kWh capacity battery.

During its first year, normal range was around an actual 193 kilometres although driving very slowly could raise the indicated range to 217 kilometres or more. The winter range at 100% charge was an indicated 160-185 kilometres but the actual range was 90-145 kilometres.

By the time I told the dealer in 2018 that I was not happy with the degradation rate of the battery, the summer range had fallen to an indicated 169-185 kilometres and the actual range was 145-160 kilometres. After the modification, although there were slight changes in the SOH on LeafSpy, the range continued to fall. As we entered winter 2018 but before sub-zero Celsius temperatures, the indicated range had fallen to 145-169 kilometres but I was experiencing actual ranges of 112 kilometres and on one occasion this fell to 96 kilometres during a night journey.

I quote the above since this is actual experience as distinct from the figures delivered from the car’s data as recorded by LeafSpy and the dashboard. LeafSpy is not indicating that there are any significantly defective cells compared to any other.

The latest data from the car say that at 77845 kilometres its SOH is 92.97%, AHr is 73.89 at 341.48V and Hx is 78.8%.

The interesting point is that, despite what appears to be at least a 30% reduction in range in three years, the battery capacity indicator in the car is still displaying 12 bars. None had disappeared before the BMS modification and none have since.

Because of the loss of range, I am finding that on the same journeys that I used to make easily on one home charge, I now have to stop off at rapid chargers and when I do, it is not just for top-ups; the car needs substantial charging.

As a professional engineer with considerable experience in electrical and mechanical engineering, I do not take the view that the Nissan BMS modification has solved a range calculation error in the software. In my view, there is a case to be made that instead the modification is disguising a genuine rapid degradation in the 30kWh battery. No matter what the battery may be reporting to LeafSpy and through its own display, the two external measures that are not capable of being manipulated by that software are the energy input from zero to 100% charge and the actual driven range.

The advantage to Nissan of having the capacity indicator in the car effectively disconnected from the true state and performance of the battery is obvious, since its warranty is linked to that display and not to the underlying reality.

I have begun a complaint to Nissan UK, having already complained to my dealer.

It would be good to see what results that your team is now having in the longer term if they concentrate on measuring the performance of ageing 30kWh batteries on a dynamometer, recording energy in and out, whilst comparing those with the indicators that Nissan uses such as its capacity display and LeafSpy measures. Your initial conclusion that the modification had solved the apparent degradation would only be true if owners were experiencing greater ranges with the correction of the error in the algorithm. In other words, if the slope of the range against age curve had improved. It would not be true if owners are instead just experiencing higher SOH and no slower loss of capacity bars; those measures are secondary and, unfortunately, capable of manipulation. I think that the VAG scandal and subsequent revelations of software being gamed by manufacturers should cause all of us to start from a position of scepticism.

Comments

Alan Lowe says
03/02/2019 at 2:32 am
Hello from the opposite side of the world in the UK.
Your research early in 2018 into the possibility of accelerated degradation of the Leaf’s 30kWh battery was of interest since I bought that model new in late December 2015, so it was one of the earliest in the UK. I live in the English Midlands, in a semi-rural area, with no particularly significant hills.
My journey pattern and mileage are relatively stable, so comparisons can be made across the years. I drive the car 26000 kilometre a year and I am the only driver. I have a home 7kW charger. The range of the car had been relatively stable for its first eighteen months but began to decline in the winter of 2017 and did not recover by the early summer of 2018. This prompted me to start using LeafSpy Pro on my iPhone. I spotted the BMS modification offered in the USA within days of its release and prompted my local Nissan dealer, who knew nothing of it but, after checking, saw that it had been released in the UK and made the change on my car.
That dealer had tried to turn me away with talk of natural degradation but I persisted since the loss of range had gone over 20%. At this time, I was able to measure the energy input into my battery from nearly zero indicated range to 100% on several occasions and it never reached 24kWh, even in mild weather with a battery starting at ambient temperature; this with a nominal 30kWh capacity battery.
During its first year, normal range was around an actual 193 kilometres although driving very slowly could raise the indicated range to 217 kilometres or more. The winter range at 100% charge was an indicated 160-185 kilometres but the actual range was 90-145 kilometres.
By the time I told the dealer in 2018 that I was not happy with the degradation rate of the battery, the summer range had fallen to an indicated 169-185 kilometres and the actual range was 145-160 kilometres. After the modification, although there were slight changes in the SOH on LeafSpy, the range continued to fall. As we entered winter 2018 but before sub-zero Celsius temperatures, the indicated range had fallen to 145-169 kilometres but I was experiencing actual ranges of 112 kilometres and on one occasion this fell to 96 kilometres during a night journey.
I quote the above since this is actual experience as distinct from the figures delivered from the car’s data as recorded by LeafSpy and the dashboard. LeafSpy is not indicating that there are any significantly defective cells compared to any other.
The latest data from the car say that at 77845 kilometres its SOH is 92.97%, AHr is 73.89 at 341.48V and Hx is 78.8%.
The interesting point is that, despite what appears to be at least a 30% reduction in range in three years, the battery capacity indicator in the car is still displaying 12 bars. None had disappeared before the BMS modification and none have since.
Because of the loss of range, I am finding that on the same journeys that I used to make easily on one home charge, I now have to stop off at rapid chargers and when I do, it is not just for top-ups; the car needs substantial charging.
As a professional engineer with considerable experience in electrical and mechanical engineering, I do not take the view that the Nissan BMS modification has solved a range calculation error in the software. In my view, there is a case to be made that instead the modification is disguising a genuine rapid degradation in the 30kWh battery. No matter what the battery may be reporting to LeafSpy and through its own display, the two external measures that are not capable of being manipulated by that software are the energy input from zero to 100% charge and the actual driven range.
The advantage to Nissan of having the capacity indicator in the car effectively disconnected from the true state and performance of the battery is obvious, since its warranty is linked to that display and not to the underlying reality.
I have begun a complaint to Nissan UK, having already complained to my dealer.
It would be good to see what results that your team is now having in the longer term if they concentrate on measuring the performance of ageing 30kWh batteries on a dynamometer, recording energy in and out, whilst comparing those with the indicators that Nissan uses such as its capacity display and LeafSpy measures. Your initial conclusion that the modification had solved the apparent degradation would only be true if owners were experiencing greater ranges with the correction of the error in the algorithm. In other words, if the slope of the range against age curve had improved. It would not be true if owners are instead just experiencing higher SOH and no slower loss of capacity bars; those measures are secondary and, unfortunately, capable of manipulation. I think that the VAG scandal and subsequent revelations of software being gamed by manufacturers should cause all of us to start from a position of scepticism.
Anaru says
17/06/2020 at 7:15 pm
We’ve got the “grabby brake” problem on our ’13 Nissan Leaf, where it appears the brakes aren’t working so well then suddenly grabs on lower speeds. Taken it to our local mechanic who couldn’t find any physical issues. Rang our dealer (who we bought the car through) about a software/firmware update and who could do it in Taranaki, twice, still haven’t heard any news (over a year now). Could anyone please, please, please suggest someone in Taranaki who could do this for us?

Brake faults in Nissan 2013-2016 Leafs

The importance of battery replacement services: October’s one-click survey

The year that was

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