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A hidden parasitic draw
Posted to Technical Tips Forum on 6/13/2014 54 Replies

Parasitic draw testing can be one of the greatest challenges that we face as technicians. Sometimes when the battery goes dead overnight and only a minimal draw is present on the vehicle it is assumed that the draw is an internal short in the battery. But is it?

Acid on the exterior of the battery can create a conductive path between the battery posts. Amperage draw is not able to be measured by any traditional means. However there is an easy test that can be done. The battery case itself is not supposed to be conductive so if you are able to read any voltage anywhere on the case there is current flow occurring. [Current flowing on battery case]

A thorough rinse of the battery and finding the cause of the battery acid coming out will bring this draw to a quick halt and keep it from returning.

Andrew from Utah

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