SEALEY Battery tester SEA AK410

The electrolyte density tester, also known as a hydrometer or acid meter, is a simple device made of plastic, equipped with a rubber pump and a tube that allows the electrolyte to be drawn from the diagnosed battery cells. Measuring the electrolyte density allows for estimating the battery's charge level.

The hydrometer allows for quick measurement thanks to a clear, colourful, three-stage scale. The "good" indication means a density level of 1.3-1.275 g/ccm, "fair" is a density of 1.25 to 1.21 g/ccm. The "recharge" level indicates discharge and a density below 1.2 g/ccm.

The properties and efficiency of the battery depend on the electrolyte level in the individual cells, its purity, and concentration. The transparent chamber of the hydrometer also allows for checking the electrolyte's purity for inclusions and deposits.