corroded battery cover no longer makes connection

Question

I have a battery cover that is supposed to make contact between two batteries. Some batteries were left in too long and now there is corrosion on the metal flange.

The corrosion is beyond repair (IE: I cannot file it down to new metal). What can I do to make contact again? I thought of using tinfoil, but that will eventually tear. I also thought of using a whole pile of solder, but I'm not sure how effective that will be.

What is the best way to re-connect the batteries when the cover is corroded? I don't think I can get a new cover from the manufacturer.

Sorry for the delay, here's the image

Answer 1

Can you post a photo of the rest of the battery compartment? Judging by the photo it looks like this piece connects the positive end of one AA cell with the negative end of another. So all you need is a little piece of metal with a bump on it, that can replace or overlay the original one.

There are a lot of places you can get a patch of metal thick enough to do the job. If the hardware store doesn't have sheet aluminum you can check the hobby store. Even simpler is to cut the ends off a soda can, flatten out the rest, and sand off the ink with wet/dry sandpaper. It's soft enough you can put a dimple in the right place with a phillips screwdriver or chopstick and cut it to shape with heavy scissors. If it's not thick enough you can double or triple it over.

The original metal piece is probably held in place by that hole in the middle, where a bump in the plastic was melted a little, flattened, and allowed to cool to shape. To get it out you might have to whittle that plastic away from the metal, or soften it with a soldering iron (being careful not to distort the rest of the piece).

Answer 2

A photo would be of great benefit.

Olin is correct - but it can be hard in practice and may result in destruction of what is left.

Ideas only:

• Shim brass may work well for you - brass sheet is available in thickness of a few thousands of an inch up. Wrapping a sleeve or "U" of suitably thin brass over the dead contact metal should work.

• You can get aluminum foil that is much solider than what is sold for food warap. And, failing in in time and needing replacing seems preferable to the alternative.

• You can but conductive epoxies, which are often just "ordinary epoxy loaded with a conductive material - perhaps copper, perhaps carbon black. You can proably make your own by experimenting. Copper filings and epoxy a good starting point My experience with similar (lacquer loaded with silver for flexible PC track repair, is that you can get connections which do not work but the improve as the epoxy sets. You need pessure on the grains to make contact to conduct.

• Ask your local industrial chemical suppliers about "Woods metal". This melts t about 70 degrees C so can be melted with hot water then poured onto the contact area. I have no experience with this - it may or may not work in this application.

Wikipedia

• Wood's metal is useful as a low-melting solder, low-temperature casting metal, ...

  Other uses include making custom-shaped apertures and blocks (for example, electron-beam cutouts and lung blocks) for medical radiation treatment, and making metal inlays in wood.

  Wood's metal is also useful for repairing antiques. For example, a bent piece of sheet metal may be repaired by casting a Wood's metal die from a good example. The low melting temperature of Wood's metal makes it unlikely this will harm the original. The damaged piece can then be clamped in the die and slowly tightened to form it back into shape.

Wood's metal has long been used by model railroad enthusiasts to add weight to locomotives, increasing traction, and the number of cars that can be pulled.

---

• Wood's metal is also used in the making of extracellular electrode for the electro-physiological recording of neural activity.[2]

---

• Also - unlikely to be a major issue here, but: : Wood's metal is toxic because it contains lead and cadmium, and therefore contact with the bare skin is thought to be harmful, especially in the molten state. Vapour from cadmium-containing alloys is also known to pose a danger to humans