Stoaty said:
This fits with the information from http://www.nrel.gov/vehiclesandfuels/energystorage/pdfs/53470.pdf" onclick="window.open(this.href);return false;
Thanks again for this link! As discussed, this presentation is for a different chemistry, but I think it is still informative since it includes most of the aging effects in the simulations that are done.
I have been looking at the curves shown in the graph at the bottom right of page 8. Can we draw any conclusions from thes pe curves? I think we can. Here are my conclusions:
- A battery which loses about 20% of its capacity in 8 years loses about 5% during the first year.
- A battery which loses 2% or less capacity in the first year MAY be able to retain more than 80% of its capacity after 15 years.
- The amount of capacity loss in year two is just slightly lower than the amount of loss in year one (at least for batteries which have a life of 8+ years).
So, do these conclusions apply to the batteries in our LEAFs? I think they do and they could potentially be used to estimate what our batteries might do in the future. Unfortunately, we would need to know *accurately* how much capacity loss our batteries had in the first year to be able to make any extrapolations.
But I don't think even those of us with LEAFs manufactured one year ago have enough information to know how much battery capacity has been lost. GIDs and capacity bars may be showing a certain amount of capacity loss, but we still do not know the *exact* defiinition of a GID and whether it is all battery capacity loss or if there are othe factors at work. Perhaps it is all battery capacity loss we are seeing, but I doubt it since TicTocks GIDs went up last fall.
While I would love to see a set of cuves provided by Nissan like the ones in the graph with all of the assumptions given, I do not see it happening. So I guess we'll have to continue to try to figure out what the losses really are based on whatever data we can collect.