garygid said:
Any chance you three with meters (Mike, Boomer, Tony) >>>
I reported my first results with my SOC meter on Sept 7, so you can add me to this list.
Here is that post, in which I computed a preliminary regen efficiency value of 73%:
http://www.mynissanleaf.com/viewtopic.php?f=31&t=5509&p=129043#p129043
For the current topic, on Saturday, 9-10, charging to 100% at L2, starting at 1:30AM with no end-time limit, the charge stopped at 271. Car's temperature when I checked at 7 AM was 80 degrees. I re-started charge, and got it to 275.
On Sunday, 9-11, I charged to 11 bars on L2 and then switched to L1 to complete charge to 100%. Hill had suggested this strategy several months ago. It did not help - charge still stopped at 274/275.
Above 11 bars at L2 the SOC rev8 shows interesting short-term fluctuations in the charging power, as the car does its "best" to squeeze in that last bit of charge.
It may have been reported elsewhere, but here are my results on charging efficiency, using the rev8 display of power going directly into the battery (voltage*current):
L1 (12A) .95KW/1.4KW = 68%
L2: (16A) 3.3KW/3.8KW = 87%
Wall-power was measured with Kill-a-Watt for L1 and TED for L2. Until now we really didn't know how much got into the battery. There was early speculation that Nissan's specification of 3.3KW for L2 charging was low, but now we know they were truthful. Many of us believed that the charger efficiency would be 94+%, like modern solar inverters.
Note L1/L2 = .95/3.3 = 29%. L1 takes 3.5 times as long as L2.
While 87% at L2 is disappointingly low, this room for improvement suggests to me that a better-designed 6.6KW charger, operating at perhaps 94% efficiency, would dissipate the same amount of waste heat, and so it could run with the present cooling system.
Stats on my Leaf:
2800+ miles
Owned 15 weeks
Charged to 100%: perhaps 8 times (including 2 times this weekend to do these tests).
Charged to 11 bars: frequently, 3 or more times/week.
Charged to 80%: ~2 times/week
No overnight charge: ~1/week
Extra afternoon charge on weekends (off-peak TOU): 2-3 times/month
Except for extra-charge days, car has 4-6 hours to cool before charging starts.
I never charge to 100% on extra-charge days.
Conclusion: having a "newer" car and charging to 100% infrequently does not help reach a full 100%. My car likely gets hotter in its garage than most of the other cars reported here, although I would think recent freeway driving raises battery pack temperature more than ambient conditions.
I suspected long before I got the car that elevated temperatures could be a problem in my garage. I installed a new insulated garage door. When I am home I frequently open a rear door and the garage door part way to allow cross-ventilation. The new solar panels on my garage roof provide some shade, but in hot weather the garage still gets perhaps 10 degrees hotter than ambient, which has reached the high 90s a number of days this Summer. I plan to install a ventilation fan on a timer before next Summer.
When I was out of town for a week, I left my Leaf in its hot garage with 50% (6 bars) of charge. This is recommended for Li-cobalt batteries.
