Hyundai says 70% is the magic number for their warranty. It's warranted for 10 years, and it transfers if I sell it. I was given the same info as
@ChuckMK23 though, 20 years through normal cycles, recommend to charge it to 100% only with a L1 or L2 charger, L3 is recommended to top out at 80%. You can limit it down to whatever you want with the software. The dealership service folks really recommend to charge with with a level 2 charger whenever possible- they seem to think the L3 charges may wear stuff out faster. I don't know how much of that is based in reality and how much is based on hearsay and what not.
The battery is built by SK Innovations (SK, South Korea... they also make all of the batteries for Samsung phones, watches, and tablets), who also builds batteries for Ford and Volkswagen.
It's definitely a gamble on a relatively new technology but even with a 30% loss I'm still able to get to work and the local hockey rinks without any trouble.
I'm really interested to see what the Michigan cold weather is going to do to battery performance.