GM did years of research into Volt battery on how to get best performance & longevity out of it. They decided that the harshest abuse of Lithium batteries occur when battery is fully discharged or fully charged. When charging the last 10% (90-100% was the worse). They had originally planned on a 80% battery rance based on this information, IE battery would never discharge below 10 % and never above 90 % of capacity. This was to extend battery life. Since I do not own a Volt, but understand price for 2013 model has dropped like a rock (closer to Volt), I cannot say for a fact what their final production design was.
How does this apply to Leaf:
1) Leaf has two charge settings 100% & 80 %. This does not seem to agree with GM's findings on its face, albeit battery tech is slightly different. When Leaf says 80% does that mean truly there is 20 % capacity more that can be charged or is system engineered so that 100% is really say 90% of true capacity. With all the problems Nissan is having with loss of battery range in Arizona, regardless of their statement
"We do not guarantee any specific range on the Leaf", if they want to continue selling them they should do what they can to reduce this problem.
Better education of buyers before delivery and change default from 100% to 80 %, user must hit button to get 100% or set timer to 100%. Early adopters generally know these things & do what they can to take care of their Leafs. Most of us Set timers at 80% as soon as possible if they was sufficient to our daily commutes. I have owned my Leaf over a year and have not lost any capacity and live in IE of California where it does get above 100 degrees in Summer.
Provide option to charge to 90%. those who need a little extra range without damaging battery by charging the last 10% shoudl have an option to get it, unless Nissan Engineers were not smart enough when designing monitoring system to allow a SW update to tell when battery was at 90% charge. IE hardware based limits.
2) Today for first time I drove my Leaf to work about 63 miles one way, with headlights on (left at 3:45 AM). Drove at 55 MPH the entire way arrived with 17 miles to spare.
Now seeing what 11 hours of 120 VAC charging will do , IE get me home? With 17 miles to spare upon arrival would 90 % charge have gotten me to work with 1 or 2 miles to spare as opposed to the 100% I started with. If so would 90% save my battery from the Arizona Fiasco. I would rather not charge to 100% each day but 80 % is not going to cut it. If no help from Nissan is forth comming the Volt at its new reduced price is looking very tempting and at 2 years I can sell my Leaf without penalty.
3)Does anyone know why Nissan will not give users option to charge to 90%? Would it help prevent Arizona like loss of battery capacity and still give more miles & smiles?