Early joye eGo batts before the eGo-t, eGo-c and eGo-c upgrade batts were regulated but not set at a constant - like the eGo-c's and the eGo-t upgrade batts of today. Earlier eGo batts would lose some power as they lost charge.
And yes, a battery that is losing voltage will change flavor - if it's a lighter flavor, you may taste more flavor (depends on flavor) - if a strong flavor, it will lose flavor or become tasteless.