derkraut said:
I was surprised to note that I lost my first capacity bar today @ 15,600 miles on my 2011 SLE.
I'm sorry to hear about your loss of a bar. I'm posting to contrast our 2011 LEAF SL battery experience with yours.
derkraut said:
I would contend that my car has been the most "babied" Leaf out there, to wit:
I've Never QC'd; I've never seen more than 6 battery temp bars; My car has never been located where the temperature exceeded 90 degrees (I live 6 miles from the beach in San Diego); I've never driven it to turtle, or even VLBW; I've charged to 100% less than a dozen times since new. About 90% of the time, my battery SOC is between 4-7 bars when not driven for several days. I've done 95%+ of my charging at night in my garage with my level 2 EVSE, using the car timer. My car is almost always in a cool (65-75 degrees) garage when not being driven. I drive in ECO 100% of the time.
You certainly have my vote for "Best Battery Babier"!
We baby our LEAF's battery in much the same way as you do, but it hasn't always been so. Here are a few differences:
- During the first six months of our LEAF's existence, it was a demo vehicle, likely sitting the entire time at 100% while being driven 2011 miles.
- For much of the first year of our ownership of the LEAF, it often sat at 80%. For the past year, we have kept it between 2 and 6 bars when sitting in the garage.
- While our LEAF has also never seen more than 6 battery temp bars and the ambient temperatures did not get above 90F much this year, it was exposed to over 100F in the summer of 2012.
- We charge to 100% about once per week, sometimes more often than that.
derkraut said:
I'm technologically challenged, so I don't have any devices to measure battery capacity like a lot of you folks do. But, I'm surprised to have lost a bar with such low mileage.
Since my car is now 2 1/2 yrs old, I guess that time is just as detrimental (or more so?) than temperature, regarding battery degradation. I still intend to drive this car for at least another 5 yrs on my original battery. Of course, not having to commute (did that for 35+yrs) gives me lots of options.
So, let me summarize your situation:
Model: 2011 LEAF SLE
Manufactured: Apr 2011?
Serial Number: 4248
Purchased: June 2011
Miles: 15,600
Garaged in: San Diego, CA
Current Battery Capacity: ~55.25 Ah
For comparison here is the same information for our LEAF:
Model: 2011 LEAF SL
Manufactured: June 2011?
Serial Number: 5926
Purchased: March 2012
Miles: 14,600
Garaged in: Winchester, VA
Current Battery Capacity: ~59.25 Ah
If we assume the batteries start life with around ~66.25 Ah of capacity (big assumption!), we come to the conclusion that derkraut's LEAF has lost about 57% more capacity than our LEAF. So, what can account for these differences? Here are a few things:
Miles: 15,600 versus 14,600 miles
Age: 30 versus 28 months since manufacture
Climate: San Diego, CA versus Winchester, VA.
Using Stoaty's Battery Aging Model (v0.83 since I don't have a newer one for Excel), I get the following predictions:
derkraut: 11.15% (Compared with 16.6% reported by car.)
RegGuheert: 10.21% (Compared with 10.56% reported by car.)
(Stoaty: Can you please provide this comparison in the latest version of your model?)
drees has pointed out one possible factor which could explain the difference:
drees said:
surfingslovak said:
The model predicts 13.66% loss using your mileage, some assumptions and a generic set of temperature data from San Diego.
derkraut lives in Rancho Penasquitos which is farther inland and certainly in an area which can easily be 5-10F hotter than downtown San Diego in the summer. Rancho Penasquitos is about 10 miles inland from the coast.
I suppose there could be some error due to the fact that while derkraut's BMS has had the P3227 reprogramming, ours has not. But, frankly, I don't think that is a significant factor. Once our BMS is reprogrammed, I guess we will find out how much difference it makes on our LEAF. (And perhaps this is why some have reported what looks like accelerated degradation after receiving the reprogramming...)
In any case, our BMS is reporting degradation
very close to what Stoaty's latest model predicts, which derkraut's BMS reports about 50% more degradation than Stoaty's (old) model predicts.
So what other factors could cause derkraut's babied LEAF to lose capacity quite a bit faster than any of the predictions out there?