DaveinOlyWA wrote:How do we determine internal resistance from LEAF Spy? If you are talking about HX, well my internal resistance is super high. I just checked its 115.75%
resistance goes up as a battery degrades, HX goes down as the battery degrades.
It might be that HX is the inverse of resistance but I haven't seen any documentation saying what HX is and I have no reason to say it is or isn't anything else.
Today I ran a resistance test using LeafDD:
Temp = 18C, SOC = 94%, Hx = 71, Miles = 62K
SOC = 94%, Hx = 71, 18C, internal battery resistance = .110 (110 mohms)
If Hx is the average value of the battery resistance (mohms) over time and NOT the present value for the battery resistance,
(battery resistance changes with temp and over time), then Hx could possibly represent the average battery resistance
Hopefully, someone will do a simple test for battery resistance on a 30/40 kWh battery;
1. No B-mode or Eco
2. Use LeafSpy on the screen that displays battery voltage and current.
3. Note the battery voltage when stopped.
4. When safe, do a hard acceleration and monitor the battery voltage and current after a few seconds.
5. Stop the acceleration, find a safe parking spot.
6. Take the difference in battery voltage (steps 3 & 4) and divide it by the peak current measured in step 4.
Voltage change - 10 volts, Current change 100 amps, then battery resistance is .10 ohms (100 mohms)
Hopefully, I don't have to rent/lease a '18 Leaf to obtain the data.
#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