Water-activated battery

This battery type is specifically designed to pollute less (see environmentally friendly claims) due to the lesser use or the absence of heavy metals.

Water-activated batteries have been used in radiosondes that shouldn't contain heavy metals since they regularly fall to the ground or ocean surface, and indefinitely remain there.

Kits using copper-magnesium cells activated by water or the liquid sample itself are also in development.

Another water-activated battery had been invented by Susumu Suzuki of Total System Conductor.

The HydroPak uses water-activated disposable fuel cartridges as an alternative to lead acid battery packs and portable generators.