lorenfb wrote:Hopefully Turbo3 will provide info on whether LeafSpy Pro ever provided an actual calculation for battery resistance.
If so, is it still in the app?
My understanding, from posts long ago, is that Hx is thought to be related to the inverse of resistance (conductance) which is why it goes down.
Hx is just a value read from the Leaf's BMS ECU. Only the Nissan engineers back in Japan know its real meaning.
Thanks for the reply. As I've been using LeafDD to actually calculate the battery resistance, it never compares to Hx even if one takes the
inverse (conductance). The only possibly is if Hx is the average resistance over time.
In any case, could you actually have LeafSpy calculate the battery resistance by just using the drop in battery voltage divided
by the corresponding increase in battery current? As an example, for a current exceeding 50 amps, just measure the battery
voltage decline and do a division. The way LeafDD does it by sensing the accelerator pedal being fully depressed and monitoring
current and voltage for a few seconds. This would be helpful in doing a comparative analysis of the 24/30/40 kWhr Leaf batteries
as it relates to battery degradation. An alternative is to do like you did for your Tesla app (TM-Spy) where you provided a graphical
display of the battery voltage verses the battery current under a heavy load. That graphic was excellent! From the graphic, one can
determine that the battery resistance is about 77 mohms (100 volts / 1300 amps). The battery power loss is about 130 kW.
Calculations values based on Tesla page link below. Here it is.
Found the Tesla link;https://teslamotorsclub.com/tmc/posts/1381783/
Leaf SL MY 9/13: 66K miles, 50 Ahrs, 5.2 miles/kWh (average), Hx=70, SOH=78, L2 charges to 100% > 1000, max battery temp < 95F, min discharge point > 20 Ahrs