Bruce in Alaska wrote:
It really depends on the amount of dissolved minerals in your tap water.


There's a fair amount in the municipal water here (showerheads clog
with time) and I screwed up and ruined the batteries, they only lasted
nine years.

Using distilled water is a wise idea, though; 'specially in third
world countries. And it doesn't have to be steam distilled, an RO
system produces distilled water too.