battery problems

I have been having a small spate of problems with battery connections. A new tv remote has to have contacts cleaned every week, multimeter had batteries cleaned and keeps growing a grey surface finish on contacts etc. I won't list them all in detail, but seems to be a recent problem generally. Is there some reason for this ? Does anyone have a cure , eg special grease or material to use as battery contacts ? Switch cleaner spray works for a short time.

Never had any issues myself. Deoxit D5 is a good quality contact cleaner and is supposed to leave a protective finish.

Vaseline used to be the one. There may be something better nowadays. Best wishes.

I've had similar problems when batteries have seemed a 'sloppy fit' in the holder - it seems that not all brands of battery are exactly the same size.

Consider trying a different brand of battery.

What sort of battery are you talking about? If it is a NiCd then the vent system under one of the terminals is producing NaOH which then turns to a white powder on reacting with CO2 from the atmosphere.

I too have a real problem with a couple of electronic tyre gauges. The contacts on the button cells are tight and corrosion free. Yet the contacts fail after several weeks. I can then clean them with a small amount of 3M abrasive and all is well for another 3 weeks! I am totally out of ideas for this one! I have a couple of other gauges of the same make, which are trouble free. Swopping batteries makes no difference, so it is a contact problem. However the contact plates are gold coated, so would not suffer from corrosion

Andrew.

RS used to sell a spray product called contact cleaner that worked well.

As Marischal said, Vaseline or silicone grease should help. In the ancient past I was the proud owner of a Sinclair ZX80. It had a memory module the plugged in the back that made it crash for fun because of the unreliability of the connections. The official fix was a thin film of vaseline, I was not impressed by the suggestion but it worked.

Deoxit D5 is one of those marvellous Mercan products that is actually very simple in composition but its disclosure is protected by describing the active ingredient as a "trade secret" in the MSDS.

IIRC, I used it in a professional environment and found that the active ingredient was simply oleic acid (derived from olive oil). So it is a mild acid that removes surface mild oxidation and leaves an oily protective finish.

Murray

I generally use a very light smear of any available grease. Colin

For cleaning battery corroded parts in old film camera gear I use distilled white vinegar and a small stiff brush.

Ed.

Years back we used to use some stuff called Electrolube to prevent corrosion on contacts. I've just Googled it, and I see it has grown into a whole family of products. See https://www.electrolube.com/

Very often contacts have a thing corrosion-resistant plating. If you have got in the habit of abrasive cleaning every time you suspect a poor contact, you may be the cause of your own epidemic...

My bother surprised me recently by showing me the can of Servisol he used on the valves in his Marshall head (it had briefly cut out twice). I hadn't seen a can for decades. He demonstrated how another amp (a small Vox) had a faint tinkling/ringing harmonic to its sound, a problem since new a couple of years ago. I gained brownie points when I not only diagnosed valve microphony, but identified the dodgy valve by pinging it with my fingernail (when turned off, of course). A swap out cured it!

So my suggestion is find some Servisol.

Neil

While it is true that gold does not corrode I have experienced many poor connections on edge connectors that are cured simply by removing and replacing the board. I looked into the problem and it seems that atmospheric pollution can force a contact apart but as the connectors are designed to wipe as they are inserted they clean and work OK until the next event. A soft eraser is good for cleaning the board edge without damaging the gold which is very thin, avoid hard erasers and glass fibre brushes as they will compromise the plating. I have known PLCs to be soldered together rather than use the connectors as vibration caused problems. It did mean that if the unit failed it would be scrapped as uneconomical to repair.

Mike

+1 on Mikes comment of gold connectors. Spot on and reflects my experience exactly

The gold connectors are ok, but the contact surface on the battery won't be gold. Is your gear in an area of high humidity/dampness.

Ian S C

Thanks for all the ideas. These devices use different batteries- AA, AAA, and button cells. I agree there are variations in sizes, all devices seem to have good and tight contacts and all batteries have been renewed with top brands. Never used abrasives for cleaning, usually my thumb or shirt lap. It always seems odd to use an insulating grease on terminals, the metal parts must touch to pass current and therefor corrode ? But I always do use grease. On the tv remote I have sprayed with silicon grease and this seems to be working for now. All devices except the remote are in damp air. Reading on the web this seems to be a common problem, suggestions that the plating on battery and contacts have changed, all pretty exotic stuff. Ian- I'm a bit short of gold just now but a good idea.

What about baby oil (mineral oil) applied with a cotton bud?

I've noticed over the years that some are fine and others go rusty really easily, even on the same product

The old HP handheld computers had a lot of battery compartment issues

Reminds me of Black Wire Corrosion.

Everyone knows it, but despite much googlepokeren, I have never seen a definitive explanation of how it happens.

Neil

I assume that it's all those electrons running about and making trouble

The flip side being those anode cathode systems on ships etc

I've seen that mainly in vehicles I've restored, usually worst near the ends and where exposed to water, I've always assumed it to be some form of wet anaerobic corrosion exacerbated by electric currents,

Regards,

Nick