N1ghtrider wrote:I question that amount of loss of efficiency. On the December trip I had 5.9 m/kwh (per dash) and 5.8 on my most recent 100-mile charge. I think it was mainly the use of air conditioner for part of this charge.
Not efficiency, but capacity.
I went through all these posts and collected the data from your 100+ mile runs below.
Note that 4 months ago, you were getting LBW at 90+ miles when averaging 5.8 mi/kWh - but this last time you only made it 84.4 miles to LBW. 16% might be a bit much, but it sure looks like you have lost some capacity between 100% and LBW. Hard to say for sure with just one data-point, and who knows what will happen if you drive it to VLBW or lower.
Code: Select all
12/31/11 111.0 mi 5.9 mi/kWh LBW 102 mi no VLBW 18.8 kWh used
1/05/12 103.1 mi 5.4 mi/kWh LBW 93.3 mi VLBW? 19.1 kWh used
1/13/12 125.4 mi 6.1 mi/kWh LBW 103 mi VLBW 114 mi 20.5 kWh used
1/22/12 130.1 mi 6.4 mi/kWh LBW 105.8 mi VLBW 121 mi 20.4 kWh used
2/17/12 126.1 mi 6.1 mi/kWh LBW 98.1 mi VLBW 114.3 mi TTL 126.0 20.7 kWh used
2/26/12 102.0 mi 5.8 mi/kWh LBW 92.3 mi no VLBW 17.6 kWh used
3/03/12 105.1 mi 5.7 mi/kWh LBW ? GOM 6 no VLBW 18.5 kWh used
3/10/12 101.3 mi 5.8 mi/kWH LBW ? GOM 8 no VLBW 17.5 kWh used
3/24/12 106.3 mi 5.7 mi/kWH LBW 93.2 no VLBW 18.7 kWh used
3/29/12 106.2 mi 5.8 mi/kWh LBW 91.3 VLBW 105.7 18.3 kWh used
4/06/12 111.3 mi 5.8 mi/kWh LBW 91.8 VLBW 108.9 19.2 kWh used
4/11/12 107.3 mi 6.0 mi/kWh LBW 96.0 no VLBW 17.9 kWh used
7/21/12 100.0 mi 5.8 mi/kWh LBW 84.4 no VLBW 17.2 kWh used
Note that the energy use from "100%" to LBW from this table, seems to have declined ~4% between new at 12/31/11 and April 2012, and then over 10% additionally, by the time of the July report.
This looks to me reflect much the same experience of declining battery capacity many others saw, relatively stable gid counts and no bar capacity losses, until rapid gid count drops, and multiple bar loss reports began, this spring.
...Assuming the LBW mile reports are accurate and efficiency was the same after LBW, it seems that N1ghtrider's LEAF has lost about 16% of its capacity from full to LBW in the last 6.5 months/4500 miles. And this is true even though the temperature was probably 20F warmer for this last report.
Or, perhaps, because
the temperature was much warmer.
Lower capacity at lower temperatures is expected, due to battery capacity.
Lower "capacity" in high-temperature conditions, that is the amount of charge the battery pack can accept
at higher temperatures, has been anecdotally reported many times. Unfortunately, TickTock's log of his gid count last year, is the only report of significant "recovery" of long-term capacity, during cooler weather. And (unless someone relocates their LEAF to a cooler climate) if
we see any future reports of battery "capacity" increasing, they probably won't happen until Winter.
The only explanation I've seen proposed for lower charge levels at higher temperatures, and the ability of the battery to recover "capacity" once lower temperatures arrive, is limitation of charge level by the LEAF BMS under high temperature conditions, rather than actual degradation of the battery, causing reduced capacity.
It is interesting that capacity reduction in Miami might be this great, even though it looks like average temperatures are ~20 F lower there, than in Phoenix.
More reports like this from "moderate" climate LEAFs, would be further evidence, IMO, that either the LEAF battery is extremely susceptible to degradation, even in relatively moderate temperatures, or there is at least some BMS operation, adding "noise" to the capacity results, shown by gids and capacity bars.