Charging patterns and battery longevity

I was reading up on Teslas, and it seems that the batteries last the longest when they are kept near 50%. Essentially, a good working range is 30-80%, and only charging to 100% right before long trips helps promote battery longevity.

I know the battery packs aren't the same, but they're both essentially a huge bank of standard lithium rechargeables, right? Does this charge range hold true for our cars as well?

Teslas have the ability to charge to a preset level, so you can set it to (say) 60%, and it'll stop when it reaches that mark, and just stay there for days. The ForTwo has no such limiter, so I'm wondering how much effort I should put into timing my charge to unplug it.


Ultimately, in life, this doesn't matter...but I like to optimize occasionally inconsequential elements of my existence for fun and profit...