After 25,000 miles I have to be honest in saying my degradation on my 2011 LEAF has been much less than I had expected at this point. In my previous experience with my ZENN and its lead-acid power pack the initial loss from a new battery pack happened in very short order, then leveled off for a bit, then died off at a relatively rapid pace. Unlike the Lithium pack in my LEAF, Lead-Acid did not do well when using more than half its charge on a regular basis. Nissan stated to expect about 20% loss after 5 years, 30% after 10. If a year is 12,500 miles I figured the rate of degradation after the initial break in period to be 2% per year based on the additional 10% of loss expected in the latter 5 years. That means a slightly higher rate would be expected for the first few years.
The other thing I was hoping for was good battery management on my part would help my numbers. So, I started working with a baseline of 15% after 5 years, 25% after 10 years. With that in mind and still taking 2% annual degradation for the last 7 years means losing 11% in the first 3 years. Keep in mind; other than Nissan's statement of expected capacity loss, all the comments to this point is pure speculation.
Based on extrapolating various trips using average GIDs per mile, I projected a winter range of 75 miles using minimal climate control. Yesterday, I was faced with a journey that would be about 75.8 miles (according to Google Maps) round trip. I could have taken the Prius but I just had to see what the LEAF could do if I really needed it to do it.
I left with a full charge of 269 GID (95.7% capacity) at 5:15 AM, OAT 37º, virtually no rain (actually a very light mist) Since I knew I would be taxing the range, I only used enough defrost to keep the windows clear. I started out driving speed of 56-58 mph. Return trip was at 1 PM mostly at 60 mph traffic permitting, OAT 43º and partly sunny. I pulled into the Tumwater DCFC at 74.8 miles and 34 GID. I used 235 GID and averaged 3.14 GID per mile. Based on that, I had about 5.6 miles of range before hitting Turtle mode at 8 GID.
The trip did end up with 5.8 miles of city driving mostly at 40-45 mph (this was "fastest" route setting) so with another 5.8 coming back along with 4 miles at this end made it approximately 58 freeway miles. Dash stated I did 4.5 miles per Kwh which calculates to 17.86 Kwh from car to wheels. Now, if I had used heat both ways, moderate settings would have averaged 1.5 to 2 Kwh and total trip time of just over 90 minutes so would have burned about 2.25-3 Kwh. Keeping with the 4.5 miles per Kwh, my range could have been as little as 67 miles. This is what I call the "family" range.
The previous day, I had a trip that was slightly longer, about 80 miles round trip. Unfortunately the LEAF was reserved so I took the Prius. Even with "unlimited" heat, I find that even settings as low at 68º on the climate control is too warm for me. The Prius fogs up a lot more (probably because of the warmer air...) so toggling defrost must be done more frequently, but my winter range would probably be closer to the 72-75 miles as stated earlier.
Previously my unscientific measurement of "family" winter range was 70 miles so it would appear that I have lost at least 3 miles. which would only be 4%. I have lost about 5% in GID count. If this holds up, I think I can project a 12% loss after 5 years and 22% after 10 years.
No comments:
Post a Comment