I used to work at the hybrid battery lab at GM, and for a while on the Volt battery itself. I'm happy to try to answer any questions (without breaking confidentiality, of course).
Personally, I'd leave battery controls to people smarter than me. Consider that the battery costs around $8,000, and that severe over- or under-charging is a massive hazard to both the battery's lifespan and the driver's life.
I tried my damnedest to find out, but nobody would talk. :(