From some research I've done, charging to 90% vs 100% roughly doubles lifespan, 80% vs 90% doubles it again, and it has less and less impact below 80%. Dischar

From some research I've done, charging to 90% vs 100% roughly doubles lifespan, 80% vs 90% doubles it again, and it has less and less impact below 80%. Discharging to 20% vs 0% doesn't seem to have as much of an impact, but still noticeable. So 20-80% or something like that is a good cycle range to use. Heat is also a big factor, well insulated batteries with active liquid cooling or similar should help a lot. With good insulation you can control the temperature of the batteries better on hot days because the ambient heat isn't warming them up as much. It's also useful in the winter to keep them warm. Battery thermals is something Tesla seems to realize is important at least, it seems like many other electric cars don't really do active thermals, and that results in hot batteries just from parking outside on a hot day.