mogur said:
I believe that many are assuming the the charge efficiency is higher than it actually is and thus that the battery capacity is higher than it actually is. I have still seen nothing that convinces me that the total capacity of the battery is more than 24Kw... It's all conjecture and wishful thinking at this point, in my opinion. YMMV.
Nothing personal, mogur, but I guess we're lost in the "in my opinion" part.
http://www.mynissanleaf.com/viewtopic.php?p=12708#p12708
planet4ever said:
At Plug-in 2010 today I stationed myself at the Leaf battery display and listened for a while as the Nissan rep manning that display answered a number of questions without a misstep that I could detect. I finally got my chance and, pointing at the board that said "24kWh total capacity", I asked, "Does that really mean total capacity, or total usable capacity?" He grinned, and replied, "The total usable capacity is roughly 24kWh. The total capacity of the pack is confidential."
How much milk is left in a gallon jug if I open a new container and drink the top 20%?
If I take one of my 10Ah LiFePO4 cells and use 80%, I've used 8Ah and left 2Ah in the can.
What if I actually NEED all 10Ah? You might suggest that I can simply take all 10Ah from the cell and I'd agree - but I want 10Ah and a long cell life. The only way to connect both those dots is to use a larger capacity cell.
It really is that simple.
As for efficiency, I'll agree with about 95% for a high-frequency CC/CV charger, and about the same for a good quality lithium cell.