The alternator reserve is is excess capacity the alternator can offer when everything on the bike is running at the same time. I have not seen any numbers for the C-14. Since it has "touring" in the name, I have to assume it has a larger alternator than a sport bike.
The reserve allows you to know many additional watts you can pull without dipping into the battery (for non-OEM things like additional lighting, heated seat/clothing, electronics, etc). Normally, you should not use all the alternator, anyway, or it could never recharge the battery from starting or self-discharge!
Anyway... anyone seen stats (especially on the 2010/2011)?
Also... access to the battery on the C-14 is crazy inconvenient. What are you guys doing to keep the battery charged during longer periods of non-use? Trickle charger? How are you connecting it? Did you install charging leads? If so, what/where?