1. From what I've read and watched, that is correct. There is an extra buffer in the battery that can only be charged by the regen. So if you live on top of a hill and drive down the hill on a fully charged Volt, then it will further charge the battery through regen. How much is this buffer? I have no idea. But apparently there is a buffer.
Originally Posted by ampera_jed
2. llninja explained this pretty well. I've done that many times. Both expending battery due to going up a hill (or accelerating too quickly) and losing bars while on HOLD as well as gaining bars by manipulating HOLD/NORMAL when going downhill.
2016 Volt LT | Iridescent Pearl | Jet Black w/ Jet Black | Comfort Package