  This paper introduces the development and testing of an experimental
apparatus for characterization of a direct charging nuclear battery. The
battery consists of a parallel-plates capacitor which is charged in a vacuum by
the current of {\beta}-radiation particles (electrons) emitted from a
radioisotope. A 63Ni radioisotope with an activity of 15mCi that produces a
20pA current was selected as the radiation source. The apparatus is unique in
its design, having ultra-low leakage current and a few options for charge
measurements. Preliminary results of a few tests are presented to demonstrate
the capabilities of the apparatus.
