Solar Garden Lighs/sidewalk lights

However, since the positive lead on the solar cell is also made of copper and the same condensation will no doubt cover this terminal, why then doesn't the positive lead corrode too?

They may help, but it`s the actual copper of the wire which turns black and brittle, the soldered joint is usually fine.

Ron(UK)

galvanic

of

this

Interesting stuff, and there is a correlation between disimilar metals corroding - sacrificial anodes and all that, but I`m not sure that is what happens in the case of nicad battery packs

It`s not only in metal cased fixtures tho, most of the garden lights here are plastic - they only cost a few pounds, not worth repairing really.

I spent a great part of my youth and early adulthood messing about with radio controlled models, and whenever a Nicad batterpack failure occured, it was always the negative wire which had turned black and literally rotted away. I don't think moisture has much of a role in the matter, as many battery packs are quite well sealed.

I wonder if the same problem occurs with types of battery technology other than Nicad, NiMH for example?

Even in cars, I believe that it`s usually the Negative battery connection which gives trouble, either at the battery termnal or the chassis ground connection.

Ron(UK)

: :Interesting stuff, and there is a correlation between disimilar metals :corroding - sacrificial anodes and all that, but I`m not sure that is :what happens in the case of nicad battery packs : :It`s not only in metal cased fixtures tho, most of the garden lights :here are plastic - they only cost a few pounds, not worth repairing really. : :I spent a great part of my youth and early adulthood messing about with :radio controlled models, and whenever a Nicad batterpack failure :occured, it was always the negative wire which had turned black and :literally rotted away. I don't think moisture has much of a role in the :matter, as many battery packs are quite well sealed. : :I wonder if the same problem occurs with types of battery technology :other than Nicad, NiMH for example? : :Even in cars, I believe that it`s usually the Negative battery :connection which gives trouble, either at the battery termnal or the :chassis ground connection. : : :Ron(UK)

I am sure there is a scientific reason for corrosion being mainly on the negative terminal but I can't quite rationalise it at the moment. I have seen many reports on car battery negative terminals and wiring corroding and I have also seen a lesser number of complaints about the positive terminal.

Without going into a scientific discussion on the subject perhaps T.R.B Watson has a plausible simplified explanation.