oilerlord said:
What I don't know is how much wear to expect at any given mileage. One owner mentioned he's noticed zero degradation after 30K miles in Arizona heat, while another owner with 48K miles said that he's lost about 25% of his range. If at 30K miles, the loss is only ~10% then the choice is easy...pocket the $3,000.
How much does a battery's age factor into this, or should I only be concerned about charge cycles? For example, there are a few "nearly new" 2012's with 4K miles or less on them. In terms of battery longevity, would a 2014 with 20K miles be a be the better choice because it's 2 years newer?
I wouldn't put much confidence in that particular Arizona claim. It isn't plausible. He has made the exact same claim several times on this board and others. I don't know what he is seeing, but I don't believe it's accurate.
Go for the newer, less used car. The battery is a constantly degrading item, and there is no practical way to "overhaul" it like there would be with a worn engine.
Battery degradation has both a "cycles" element and a "time" element. If one left a charged up car in the sun for three years and hardly ever drove it, the battery would still be in sad shape. Think about laptops that are left plugged in...in a few years the battery is weak even though it is never used.
Better yet, look into options to lease a brand new one. In three more years, these used cars will be essentially valueless. The cost of ownership will be more than the lease payments would have been, and even if you keep the car it will be obsolete and quite possibly degraded.
If you go to the Ford website, they are offering a three year 31,500 mile lease at 237/month with 882 due at signing, call it roughly 260/month allocating the 882, a little over $9K over three years. In reality, you can probably get a much better deal than the nationally advertised offer plus depending on where you live there may be local government money.
The paradigm of "I keep my cars for a long time" doesn't work well with EVs. They degrade, and better ones are constantly being offered.
I can't tell you how happy I am that the leases on my FFE and my Volts are expiring over the next 15 months. I get to replace them with newer, better models, probably at lower payments.