battery-pack contacts Canon LP-E6 battery packs (such as those using in my 70D camera) have two fine connector wires used for charging them. These seem to be a weak point, as (if left to themselves) they eventually fail to connect well, which means that they do not charge adequately, or (in the field) do not run the equipment at all. One experimenter discovered that scrubbing them with the edge of a stiff business card helped to make with (nonCanon this time) charger contacts them good. So I considered something more extensive. Parts: squeeze-bottle of cleaner (I use a citrus-based cleaner from PlanetArk, which seems to be able to clean almost anything off without being excessively invasive); spray-can equipment required of WD-40; cheap tooth-brush, paper towels (or tissues, or bum-fodder). Method: lightly brush head spray cleaner onto contacts. Gently but vigorously rub along the contacts with toothbrush. Paper-dry the contacts. Lightly spray WD-4...
Linux Advocate in Western Australia