LeftieBiker wrote:I honestly don't know how much power the shunt resistors 'waste,' but given the amount of time they run, the fact that they are only converting power from the highest-SOC cells to heat, etc, I'd say it isn't much. Some balancing algorithms just switch the higher cells out of the circuit, allowing the lower-SOC cells to 'catch up'.
I think it would be possible to figure out from observing ChargePoint data,
ChargePoint provides the amount of kWh that have been delivered. If you were watching the ChargePoint app and noticed that value the first time that the SOC reached 100% and the rate of charge dropped to 0%, that would be the delivered kWh before cell balancing commenced.
Then you could make a note of the total kWh's delivered after the three+ separate times that power is shunted from the most charged cells to achieve balance.
The difference might be part of the 'waste overhead' from cell balancing. My W.A.G. (wild Allan guess) might be 0.3 to 0.5 kWh out of perhaps 13 kWh to go from a SOC of about 20% to 100% to 99% to 100% to 99% to 100% to 99% to 100%.
During the several hours of cell balancing, my observation was that about 1.0 kW/hr was being delivered about half that duration to bring the 'low cells' up to 100%. However, that wouldn't be 'wasted' as actual charge is being delivered.
Actual waste would be during the 'shunting' of cells that were at 100% when heat was brought about to draing cells to achieve balance.
I will try to take a closer look at the ChargePoint log that is recorded to my Andriod 7.1 device. I'm trying to figure out to get a 'screen shot' from my smart-phone ... Power-off + reduce-volume doesn't seem to work. Drat.
I suppose this info could also be derived from a Kill-A-Watt device at the wall-plug.
I don't have the LeafSpy app or ELM-327 connector, but my speculation is LeafSpy might provide reasonable numbers of how many kWh were delivered after the first time a SOC of 100% was achieved.
2015 Leaf S. Bought 2 year lease turn-in with 14,500 miles. Drive about 14k miles/year. Most charging from 'free juice' at nearby ChargePoint or Nissan or other free L2 public chargers within walking distance. ICE is rarely driven pickup truck.