The Draper Battery Hydrometer is a precision instrument designed for testing the specific gravity of electrolyte solution in individual battery cells. This battery fluid tester features a colour-coded graduated scale to provide clear visual indication of battery charge status, making it an essential diagnostic tool for automotive technicians, mechanics and maintenance professionals working with lead-acid batteries. Manufactured with a durable glass tube, PVC bulb and spout, this hydrometer measures electrolyte density with graduations of 0.005 g/ml for accurate readings. The colour-coded scale simplifies interpretation: red (1.100-1.205 g/ml) indicates a discharged battery, white (1.205-1.260 g/ml) shows the battery requires attention, and green (1.260-1.300 g/ml) confirms a fully charged state. Calibration should be carried out at 20°C for optimal accuracy. Ideal for workshop diagnostics, fleet maintenance and battery testing applications, this hydrometer allows technicians to assess