Power reserve indicator for a timepiece

A timepiece power reserve indicator for the display of the power reserve indication of a plurality of energy accumulators including a first barrel and a second barrel each including respectively a first output and a second output respectively cooperating with a first accumulator input and a second accumulator input of a dual transmission drive train leading to two differential inputs of a differential mechanism comprised in said power reserve indicator, said two differential inputs being formed respectively by a first input plate and by a second input plate and wherein an output wheel of said differential mechanism cooperates with a mechanism for the display of the total power reserve of said plurality of energy accumulators, wherein said first accumulator input and said second accumulator input are part of the same first input wheel set of said differential mechanism, which is a ball bearing differential, and are coaxial about the same first axis and are pivotally movable about said first axis independently of each other, and wherein said first accumulator input meshes with said first input plate pivoting about a second pivot axis, wherein said second accumulator input pivots integrally with an output wheel which meshes with an intermediate wheel pivoting about a third pivot axis driving said second input plate of said differential, also pivoting about said second pivot axis, said differential including, pivoting about said second pivot axis, a hub driving both said output wheel and a carrier plate which carries one or more ball bearings in contact with both said first input plate and said second input plate, both mounted for free rotation on said hub, under the action of friction imparted by one or more springs.