Put 10,000 km into my first battery over 5 years, very bad etiquette the entire time: I was basically charging it to 100% most days and returning with 0% at least once a week. Motor died after 4 years (Shimano e8000), had to pay for a new one, battery degraded about 10% which is what I expected. I'd be more worried about the resale value than anything else, these things are way overpriced and no one wants to buy them used...