[outworlder]

Way different chemistry, reserve capacity, active thermal management.

Of these, the chemistry should answer for most of the improvements. Electric cars as a rule do not use standard lithium ion batteries exactly because of the degradation. Instead, they get less energy density.

[thescriptkiddie]

Actually Tesla batteries use the same chemistry as most notebook batteries, the ones that prioritize energy density. The real difference is the usage pattern. Notebooks are usually left for days or weeks with a 100% charge and then drained to 0% when the battery actually gets used. Electric cars are charged to 80-90% at the beginning of each day and then drained no lower than 10-20% barring extreme circumstances. Anyone who flies RC aircraft (which use the same battery chemistry) will tell you that the only thing worse for a lithium battery than storing it at 100% charge is draining it all the way to 0%.