Kia ora koutou
Another 100 enrolments! We were delighted to receive another 100 vehicle enrolments since we publically launched the project around 3 weeks ago. Bring more on!
July’s 1-click survey: We asked you whether “Getting stranded by running my battery flat is a real worry for me”. There was superb and rich response which we have summarised at https://flipthefleet.org/2017/getting-stranded-by-running-my-battery-flat-is-a-real-worry-for-me-1-click-survey-9/ Most of you thought that range anxiety was an exaggerated and easily managed issue; though it takes a bit of time to learn your EVs range capability at first. Thanks Dan Capper and Morgan Knoesen for suggesting last month’s question.
Now that we have a better sample size, we issued a nationwide media release about the poll, coupled with a few relevant statistics from your end-of-June upload of data.
Consumer protection: We have been fielding increasing numbers of inquiries about Battery State of Health (SoH) and odometer readings (km) for Nissan Leafs of different age. Some are from people wondering whether to buy a particular vehicle, others from people wondering if they just bought a lemon, so your data on SoH and odometer seem valuable for everyone to benchmark their vehicle against. Hence we have created a table of SoH and Odometer readings for each year of manufacture at https://flipthefleet.org/2017/nissan-leaf-check-your-battery-before-buying/ which we will update each month. Attached here is a scatter plot of SoH (as a %) versus odometer for Leafs in your (eNV200s are not included as there are insufficient registered in Flip the Fleet so far). The is so much scatter here that we are loath to even fit curve or line to the pattern. When we have more data we will be able to fit a statistical model to disentangle the effects of vehicle age, odometer, charging patterns and region on battery state of health. Obviously it will be very valuable to discover what drives the variation so that we can advise on how best to conserve battery health – but that’s a job for a year down the track.
Cheers
Henrik, Dima and Jefferson
This is great info. Thank-you!
Can you confirm that your data shows the SoH values reported from LeafSpy and not the Hx values? The reason for asking is that I note that you have reported in one of your tables SoH %values with 0.1 resolution. On my version of leafspy, SoH % is reported as a whole number – no fraction, but Hx is reported to 0.01 resolution (and generally has a lower value than SoH).
I am intrigued to see that your data appears to indicate that the SoH values of 100% are not seen in the low mileage cars – only appearing in vehicles with >15000Km on the clock!
The table is reporting percentiles but is based on a frequency distribution of State of Health recorded to the nearest percent (not the Hx index). The added decimal places are inserted as the software interplates between adjacent bars in that frequency distribution.
You are the second person to have misinterpretted the Table (your second comment) – which is our fault in the way we laid out the table. i.e. the last column of the table is the odometer reading for cars of different years (first column) in each percentile group. The middle two columns are totally independent of the last one on odemeter readings. We will now split the table in two to separate the odometer from the SoH recods to avoid others falling in to the same trap of thinking columns 2 and 3 are linked to the column 4 in some way. Apologies for not making it clearer from the outset.