TCS question

[ReV:-O]

hi,

i have a quick question to do with my hyperion duo charger. its about terminal capacity selection.

if you set the TCS to say 50%, will it charge the pack up to 50% from where it already is? so say each of my cells is 3.9v, will it charge it up 50% from there?
or will it charge 50% of the total pack, to would it actually drain the pack a little bit?
if your battery is fully charged, but you realise you cant run it for a while, could you set the TCS to 50% and charge your lipo, and it will actually discharge it by 50%?

thanks guys