Torch battery terminal corrosion - vinegar or baking soda?

[David]

I have a bike light which has intermittent contact which seems to be due to mild corrosion on one terminal.

An on line search suggests (some sites) vinegar or (other sites) baking soda.

I am a bit wary of cleaning up with fine sand paper because in the past this seemed to remove a protective coating and lead to corrosion from moisture in the air.

Any topical tips?

Cheers

Dave R

[alan_m]

Use a q tip (cotton bud) to clean it - perhaps soaked in a little vinegar.

If you want to abrade it a nail file or nail sanding pad works well.

After cleaning put some grease or Vaseline/Vicks on it. The battery will still make electrical contact if it is a tight enough fitting. Often the spring on the negative contact can be stretched a bit if the battery is loose.

[John Walliker]

If the battery was an alkaline manganese type, the residue will be mostly potassium carbonate after a while. Plain water is probably the best thing to use for cleaning. John

[Thomas Prufer]

I'm assuming the result of a leaked battery? White furry glop?

Then: Vinegar, phosphoric acid (part of some descalers), sulfamic acid (part of some descalers), ... repeat until the white stuff is gone.

I'd see if it's possible to open the bike light easily, the leaked electrolyte likes to wander.

I have also recently added these steps: Clean out with a vigorous spray of tap water, rinse with a squirt of distilled water. Let dry open. Has worked for me.

I think the later corrosion may be from skipping the last two steps, with the remains of a mix of acid and alkaline helping the corrosion along.

I have also, in the past, removed the contact and tried to coat it in tin/solder: doesn't work well, even with scraping and flux, and not worth the effort.

Thomas Prufer

[The Natural Philosopher]

If its corroded its already lots any coating it had

A pencil with eraser in a drill might be a kind abrasive to start with and would reach down into any tubes that that cannot come apart.

[Brian Gaff]

Depends. I think these are usually brass or some kind of springy stuff like phosphor bronze. Can the unit be taken apart to get at the bit? On most torches you got problems due to dissimilar metals on the battery and the contacts. Abrasive now might be the only way, since the corrosion has probably eaten any plating by now. Some Vaseline around it all as you put it together can lengthen the time between cleaning. Brian

[Chris Green]

Yes, it's the first thing I do with corroded battery terminals, run it under a tap.

[Animal]

Yup. Once clean, always use vaseline or silicone grease on it. Other greases are not suitable. If the trminals get horrible another option is solder very flimsy flex to the pcb & wrap round the spring.