Hi Michael

A couple of months back a mate and I were discussing them for a solar system. When telephone exchanges were mechanical they were used to back up the power supply. Did the railways also use them? They last for years and years if looked after.
Unfortunately the feed back tariffs are now so low in Australia that the system we were designing was not feasible.

This link describes them…. **LINK**

Or a general search… **LINK**

Regards
John

I remember having an ex minors lamp I used for caving ( speleology if you want to get posh), these were much better than the older lead acid ones, encased in stainless steal. And could take quite a battering.

they used potassium hydroxide for the electrolyte and the cells were 1.2 volts ( 3 cells in the minors lamp if I recall correctly.

very hardy and virtually indestructible.

Nife cells were the standard type used by miners in the past, don't know what the current standard is.

Remember dad talking of them in relation to his war time work as a Radar mechanic (may have been standby power).

As said above, the electrolyte is potassium hydroxide, but with the addition of a small amount of lithium hydroxide. The latter acts as a preservative for the grid material.

Best stored discharged.

I think that before the days of NiCads, the NZ Railways used them for the power supply on passenger trains.

Ian S C