What happens to electroincs when a battery corrodes?

[rogerg]

Hi all,

Recently I've had two unrelated situations where a battery inside a battery powered device has corroded (presumably due to age) and following this the device has no longer functioned (once cleaned and new battery fitted).

The first was my Orion Accufocus unit (same as the Skywatcher motor focuser as sold by BINTEL). The 9v battery in the hand controller corroded after a long time of little or no usage. Once I removed the battery, cleaned the contacts with a brush and rag, and fitted a new battery, the unit still fails to operate. The motor also fails to operate via the PC control box, so the problem would seem to be in the motor its self.

The second which you may laugh at, was our pepper grinder which is electronic. Again, the battery corroded and once cleaned and replaced the device no longer functions.

Question:

Is it normal that a corroding battery would damage the device or is this just co-incidence? Is it likely to be something simple to fix?

Reason I’m asking: I want a working focuser! But rather not have to buy a new one :)

Thanks,
Roger.

[mithrandir]

Roger, it is quite likely one or more of the wires is corroded where it is joined to the battery contact. If you can get the contacts out, clean and recrimp/resolder you might have some luck.

PS. I know you can't get a 9V in the wrong way round, but did you put the batteries in the pepper grinder in the right way round?

[rogerg]

I'll see if I can suss out connections. Not sure how to open up the motor but will take a look.

Batteries were correct. Thinking about it more now, we did use the pepper grinder now and then but just not very often so the one set of batteries had been in there ages (year(s)). I'd guess I did use it only a couple of weeks prior to finding it dead and the corrosion.

Thanks

[killswitch]

Grab a multi tester and do a continuity test on all the contacts.

If the electrical paths is all good then its probably a seized motor. The fixed magnets inside probably fell out of place or the bearings/commutator has seized from old age. Try giving it a push start :lol:.

[gary]

Hi Roger,

Alkaline batteries commonly contain potassium hydroxide which is a strong base.

The white salt that appears around the battery is potassium carbonate forming
where the potassium hydroxide reacts with carbon dioxide.

In any case, they can be bad news for your electronics. They cause corrosion
of the copper traces on circuit boards and etch the metal leads off components.

When the battery vents, the material can make its way throughout an appliance
enclosure and given time, the damage can be irreparable.

This is the primary reason all battery manufacturers recommend removing batteries
from appliances when they won't be used for extended periods of time.

Wash your hands well if you come into contact with it.

Best Regards

Gary Kopff
Mt Kuring-Gai NSW 2080
Member Institute of Electrical and Electronic Engineers (IEEE) 36 years.

[rogerg]

Great explanation, thanks.

I'll be taking another look at it all on the weekend coming.

:thumbsup: