A do-it-yourself (DIY) thin film battery provides battery assembling components suitable for separate storage and easy fabrication. With through hole plating or sidewall plating, the current collectors of the anode and cathode, extend from one side of the substrates to the other to facilitate electric coupling with the electronic product outside. Through either soldering or direct contact with conductive tapes, the battery components mount with each other. Thus, the battery components can be combined to have batteries of various voltages and capacities via series or parallel connection means without extra circuits.