I'm also interested to hear flip the fleet thoughts on the greencabs post.

I wonder though: perhaps greencabs dataset are an outlier because their use as a commercial taxi company is so different to the average private driver. If you need to drive ~200km/day and quick charge 2-3/day to maintain good battery, that's too much effort for most people and the flip the fleet data are still relevant.

Other thoughts

Do cheap OBD2 devices and the use of Leaf spy lite give different readings. Leaf spy lite could be poorly written like many software programs.

My30 Kw Leaf (UK) Readings are all round the place Varying from as low as 82% SOH to 84% My last 25% of battery regularly show 50+ Kms left on the GOM 

My battery has not degraded in the last few months since I have used the OBD2 tool I have a cheap one and use Leaf Spy Lite My last charge to 100% showed 188kms on the Gom This was after some Motorway driving but mainly around town.

Leaf spy showed it had only charged to 97.4%. I intend to test a full drive around town (50 kph only) to see what sort of KM I get and then do a full charge (fast) to see what the GOM reports.

I do wonder about the software and the cheaper OBD2 devices.

These are only my unscientific findings

I don't think the quality of your OBD2 device or of the app is distorting your readings. SOH is a message that's passed over the car's data bus and Leaf Spy just observes and displays it.

The state of charge shown in Leaf Spy is different to that reported on the dash. Leaf Spy reports the true state of charge of the battery pack, the car shows the charge over a smaller range; when you fully charge it's not actually 100% full and when it reports 0% (or -- Arghhh!!) it's not completely empty. I guess this is to protect the battery. I have found that on my 24 kWh the Leaf Spy SOC and the car's SOC only intersect at about 80%. 

Leaf Spy - Lite or Pro - simply reads the numbers reported by the battery computer. Whether the OBD2 dongle is cheap or not makes no difference either for the same reason. The dongle is simply the channel over which Leaf Spy reads out the battery computer's opinion.

frednz:

 

Based on that, here's some recommendations that may help you get the most from your Nissan Leaf battery (from a taxi companies perspective, of course):

 

 

1. Charge to 80% rather than 100%.
2. Charge at 25% rather than running the battery low.
3. Use the car.
4. Don’t be afraid to fast charge."

 

It would be good if the "Flip the Fleet" people could comment on why not all 30 kWh Leaf owners are in fact experiencing the fast battery degradation problem. Is their research robust enough to take the above facts into account?

 

I think its fair to say a Taxi companies usage of the cars is not really relevant to most people in NZ.  They are clearly a special case, if their batteries were degrading faster nobody would be surprised.

The fact that their batteries seem to be doing much better than the average points to a possible issue with the BMS on the cars, which is estimating the state of the chemical composition of the batteries.  Its just an estimate and its not 100% accurate, but its important because the BMS controls the amount of charge put in and taken out of the battery.  So even if the degradation is just because of a pessimistic BMS, its still real and affects the usage of the car.

I think others on this forum and other forums have shown that 'exercising' the battery pack increases the BMS's optimism and allows you to increase your SOH and range.  Fast charging seems to also help a lot.  Greencabs is doing both so they are keeping their BMS estimate higher that way.

I think if they sold those cars to the average Kiwi today, who drives < 15000km a year, the SOH, usable capacity and range of those cars would plummet and those buyers would not be happy about it.

It would also be interesting to find that multiple rapid charges daily is actually good for the battery long term. That goes very much against the received wisdom of rapid charge == hot battery == battery damage.

SaltyNZ:

 

It would also be interesting to find that multiple rapid charges daily is actually good for the battery long term. That goes very much against the received wisdom of rapid charge == hot battery == battery damage.

 

Batteries degrade with usage, if somebody could make a battery that got better, it would be a major scientific breakthrough!

Its much more likely a problem with the batteries and/or their software.

happyfunball:

 

Batteries degrade with usage, if somebody could make a battery that got better, it would be a major scientific breakthrough!

 

Well, yes of course, but I mean that the received wisdom is that they degrade faster on a per-km basis if you're constantly fast charging them vs. slow charging so they stay cool.

SaltyNZ:

 

Well, yes of course, but I mean that the received wisdom is that they degrade faster on a per-km basis if you're constantly fast charging them vs. slow charging so they stay cool.

 

I think they degrade more with age rather than usage, according to the Nissan owners manual anyway.  They expect 80% SOH after 5 years, milage doesn't seem to  figure into it.

I guess it could degrade slower charging one way instead of another without violating the science, as long as it was still degrading overall.  There is an optimum charge rate, and deviation from that causes more degradation, so I guess  somebody could make a battery that was healthier using fast charges rather than slow, but I've never heard of it?  Would be useful for taxi companies.

As it is, its supposed to be better to charge at 240v 16A than it is at 120v 10A because the optimum charge rate is higher than the US home socket default.

http://www.cleanfleetreport.com/exclusive-nissan-leaf-battery-fix/

From the above:

"Nissan released a statement today about a fix for 2016 and 2017 Leaf battery electric cars that are experiencing indications that their vehicles’ 30 kWh batteries were losing range and capacity at an accelerated rate.  Owners of these EVs were reporting that their cars were losing as much as 25 percent of their car’s range and battery capacity in as little as 15,000 miles."

Nissan Customer Service Campaign Statement

On June 6, 2018, Nissan began conducting a customer service campaign in North America to reprogram the lithium-ion battery controller in 2016 and 2017 model-year LEAF vehicles equipped with a 30-kWh battery, to correct the calculation used for the battery capacity level gauge and distance remaining of the vehicle.

The displayed vehicle range and battery capacity level gauge on these vehicles are displaying range and capacity that is lower than the actual amount. Reprogramming the controller will result in an accurate display of the LEAFs battery capacity and trip range.

This service campaign is open to all 2016 and 2017 LEAFs regardless of mileage or if they have had their battery previously replaced.  Owners should contact their local dealer to schedule the update. After the reprogramming, the balance of the original lithium-ion battery and battery capacity warranty will remain in effect for any customers who experience warrantable battery degradation.

So, what do you think of that?

Good news Just need to wait for the software to get distributed to NZ Shouldn't take long

frednz:

 

"Nissan released a statement today about a fix for 2016 and 2017 Leaf battery electric cars that are experiencing indications that their vehicles’ 30 kWh batteries were losing range and capacity at an accelerated rate.  Owners of these EVs were reporting that their cars were losing as much as 25 percent of their car’s range and battery capacity in as little as 15,000 miles."

 

So, what do you think of that?

 

Thats timely, and seems to indicate its a BMS problem.  The statement says no increased range though, so I wonder if this is just moving the bars around like they did on a previous Leaf update.  Hopefully not!

Good to see Autolink are on the ball

Just received this email From Sarah Ryan

Please see Nissan’s announcement below regarding the 30kwh battery models.

We have been advised there will be a recall to update the software. No time frame as of yet. We will keep you updated as further information becomes available.

Kind regards,

Sarah