Specific gravity detecting device for lead-acid battery

摘要

A specific gravity detecting apparatus for a lead-acid battery having two electrodes adapted to be immersed in an electrolyte to provide a potential difference therebetween which is indicative of the specific gravity of the electrolyte. One of the two electrodes is a lead electrode composed of a collector 6 made of lead and a lead alloy and a porous lead body 4 covered by an acid resistant porous sleeve 3; the other is a lead dioxide electrode composed of a collector 6' made of lead and a lead alloy and a porous lead dioxide body 5 covered by an acid- and oxidation-resistant porous sleeve 3'. The two electrodes are charged normally or as required while there is no necessity of obtaining specific gravity data, and later discharged with another lead electrode as an opposite electrode so that, in the open-circuit state, the potential difference between the lead electrode and the lead dioxide electrode is accurately determined. In preferred embodiments, the two electrodes and a temperature sensor having an acid-resistant material as its outer portion are mounted in a single molded body 1 made of an acid-resistant material.