Cleaning battery contacts

[jebem]

(06-20-2014 03:08 PM)anetzer Wrote:  

(04-13-2014 05:23 PM)sylvandb Wrote:  If you have the contacts out then you could use some solder (lead-free if you like) to tin the contacts. This requires substantial heat and beware

I read somewhere, that covering battery contacts with a layer of solder is only advisable in devices with low power consumption? IF that is true, I would guess that every calculator covered here falls into that category...

I don't like to use solder as the condutive material for power contacts, but that is one valid solution.
Solder having Pb will oxidize and create a high contact resistance hence lowering the available voltage for he calculator. However, as the current here is so small the voltage drop should be minimal.
However it requires very high temperatures to force the contact metal material to merge with the solder and in the end it will look ugly as the solder covering will not be uniform.
For that reason I just use a metallic brush to remove the oxidation covering and then apply electrical contact cleaner (dry version withou oil, in spray bottles) to remove all remaining acid/base/dirt components, and it should be fine for the next year or so. A bottle will last for many years of usage.