Instrument for testing of the sources of power (storage batteries and batteries) the compact, safe instrument, which makes it possible to instantly determine the wear of storage batteries or batteries. Model 3555 is intended for testing of the sources of power of small capacity (batteries for the cell phones). Possibility of testing the sources of power (batteries), without disconnecting them in this case from the users. Three stages of the estimation of batteries and storage batteries: Pass, Warning, Fail. Simplicity before the use.