Water-activated battery

Additional recommended knowledge

What is the Sensitivity of my Balance?

Daily Visual Balance Check

Essential Laboratory Skills Guide

A Water-activated battery is a disposable battery that does not contain an electrolyte and hence produces no voltage until it is soaked in water for several minutes. Typically, a large variety of aqueous solutions can be used in place of plain water. This battery type is specifically designed to be more environmentally friendly due to an absence of heavy metals. Water-activated batteries are used most commonly in radiosondes which cannot contain heavy metals because they regularly fall to the ground or ocean surface and remain there indefinitely.

A carbon-magnesium battery, named NoPoPo, coming in AA and AAA sizes, was released in Japan in 2007. The batteries come with a syringe to inject water or electrolyte, such as juice. Diagnostic kits using copper-magnesium cells activated by water or the liquid sample itself are also in development.

Aluminum anodes are used on many water-activated batteries designed for use with seawater and its high salinity.