specialgreen wrote:johnlocke wrote:If you plan to keep your car for 10 years better plan on at least one battery replacement out of your pocket(currently $8400 with exchange) unless you can live with 50% capacity.
When we're talking about battery life, please avoid exaggeration.
Either the battery degrades more than 20% in 8 years, or it doesn't. If it degrades slower, the worst case is that you hit 80% one day outside warranty, or just under 2.5% loss per year. After 10 years, you'd still have 75% SOH (not 50%).
If it degrades faster that 2.5% per year, then you will have a battery replaced under warranty before 8 years. If the initial battery was replaced after 4 years and 1 day (5% degradation per year), then the replacement battery may reach 80% after 8 years and 2 days (2 days out of warranty). At 5% loss per year, after an additional 2 years, you'd be down to 70% (not 50%).
If there were a group of customers needing two battery replacements under warranty, the worst-case would be 7.5% loss per year, such that the 3rd battery reaches 80% one day outside the 8-year warranty. In that case, after 10 years, the car has 65% SOH, not 50%.
For a customer with 3 replacements under warranty, worst-case has the 4th pack reaching 80% 1 day outside 8 years (10% loss per year). After ten years, you'd have 60%, not 50%.
Since actual loss is not linear, I could believe that customers who degraded to 80% in 2 years might degrade to 50% in 2 more years. But I believe the percentage of 30kwhr owners getting a new pack every 24 months is small (even before the firmware correction). The comment "if you plan to keep your car for 10 years... live with 50%" implies that 50% after 10 years is the general case. I don't see how that statement can possibly be accurate.
There are a couple of errors in your assumptions. First battery deterioration in a Leaf battery is closer to linear then an inverse log function. second, the losses for the 24 KWH battery in hot climates are on the order of 7-10% per year ( that is 7-10% of original capacity each year is lost). Hence the replacement under warranty in under 5 years. For the 30 KWH battery, the annual loss was closer to 15% a year. Hence the replacement of batteries in some cars in less than 2 1/2 years. Under that scenario, you could expect to replace the battery at least twice and possibly third time just before the warranty ran out. Nissan has updated the LBC firmware so we are essentially back to square one with Nissan claiming that the previous failures were essentially a math error. It will take a year or more to accumulate enough data points to see how well the battery holds up. As others have pointed out battery replacement will not occur until the battery is down to 65% of the original capacity or less ( 8 bars remaining) not 80% as you state. If the battery did indeed lose 2 1/2% per year, I would be quite happy.