For those that have access to a 2018 Leaf, do QC charging, and use LeafSpy, your help obtaining battery data on that vehicle
would be very useful in determining what battery parameter could be contributing to having the charging time progressively
lengthened during a long distance trip. It appears that the 2018 Leaf’s BMS controller is reducing the charging current as the
battery gets progressively warmer during a lengthy trip. This has not been the case for earlier Leafs even though the BMS does
reduce the charging current over time for the earlier Leafs, but it appears not based on temperature nor based on the number
of previous QCs during a trip.
The process should only take a couple of minutes during the starting phase of the QC to obtain the data:
1. Once the vehicle is parked adjacent to the QC with the Leaf’s power still on with no accessories turned-on, e.g. the fan/AC,
measure the battery voltage (V1). It should be greater than 325 volts. Then measure the battery temperature (T - degrees C).
Write these values down.
2. Next the charging voltage (V2) and charging current (I) need to be written down immediately once the QC device begins
the charging process
using LeafSpy. If the QC device provides these values, just use those values displayed on the QC
device like in this post; http://mynissanleaf.com/viewtopic.php?f ... 70#p523610
3. Once all the data are taken and time permits, please post them in this thread using the following form;
V1 - XXX, V2 - XXX, T - XX, I - XX
4. The data will then determine the battery resistance by this calculation; battery resistance = (V2 - V1) / I
As an example, V1 = 355 volts, V2 = 365 volts, I = 80 amps, then battery resistance = .125 ohms or 125 mohms.
Battery resistance varies with temperature, so it's critical to determine the temperature at the being of the charging process.
Based on your values and other’s values, a comparative analysis between the early Leafs and the 2108 Leaf should provide
insight into how the chemistry might be different and what one might expect about long term battery degradation the result
of lengthy and multiple QCs combined with high speed driving during a long trip.
Thanks for your help.
#1 Leaf SL MY 9/13: 76K miles, 47 Ahrs, 5.0 miles/kWh (average), Hx=70, SOH=73, L2 - 100% > 1000, temp < 95F, (DOD) > 20 Ahrs
#2 Leaf SL MY 12/18: 10.3K miles, SOH 109Ahrs/115Ahrs, 5.2 miles/kWh (average), DOD > 20%, temp < 105F