Gold Plating/Corrossion

[busbar]

Seen http://www.cool-amp.com ?

 

[lightlover]

SILVIRON - you out there ?

Busbar,
that stuff sounds amazing. Almost more amazing than the amazing price

PhilAlex,
I've looked at some stuff that was advertised as a Silver-Plating solution, but it leaves an extremely thin coating of silver. It was meant for "repairs" to silver plated stuff that had worn thin, and if you even polished it vigorously, it would come off. I can't remember what it was called, but it was sold in some Department stores and the Sharper Edge, gadget-y type shops.

But I'm puzzled - doesn't Silver tarnish to a Silver/Sulphur compound pretty quick, especially when subjected to heat ?

I've been meaning to get a few squares of Gold-leaf to try that out. The problem there is that it's often lacquered, and also, superthin, so I don't know how it would last with insertion once, let alone removal/insertion/removal.

What about sealing the contact area with conductive lube and some kind of glue or plastic wrapping ?

lightlover

 

[PhilAlex]

Maybe my friendly Flashlight fellows can find Phil a formula for coating the ENDS of a battery with a material (Gold/Rhodium) which is corrossion resistant?

I have to install batteries in a meter, going inside a factory. They're lithiums, and they will be there for a few years. Failure is not an option, so they have to be plated to make better contact.

Another caveat: I can't solder or mechanically weld them to the terminals...

I know there used to be a liquid on the market that you rubbed onto metal to gold plate it, and I've seen the "Fake" gold plating that Car Dealers use on ornaments, and I've seen a cheezy penlite with an aligator clip and 2AA's for a homebrew Gold plating kit.

What I'm after is just a way to make the ends of my batteries corrossion free. I don't care if it's gold of rhodium or whatever. As long as it doesn't cost me 2 weeks wages.

PS: No jeweler will immerse a battery in his plating bath.

Phil

 

[Silviron]

Jahn (*something ridiculous) emailed me to ask me to put in my two cents on this.

What kind of lithium battteries are you using? I wouldn't easily do ANY kind of plating on a vented lithium cell like an energizer AA lithium, or a 123 etc...

I'm not a good enough chemist to say offhand what kind of reaction you might get if you got either cyanide or acid from a plating solution inside the battery... but since just getting water in them can result in explosion and/or noxious gasses...

.....

On a Tadrian, Saft, Electrochem etc. Lithium that doesn't have venting it wouldn't be too much of a hassle. Or on a "coin cell" type battery. But with a vented type, that would require positive sealing of the vents prior to plating, then careful removal of all of the seal after plating.

Whatever, I wouldn't use immersion plating at all, I'd do what is variously known as brush or pen plating. Some of those kits you can buy WOULD do the job. Even a light plating would suffice since you aren't going to be removing and replacing the same battery on a regular basis (are you?).

Unfortunately, the crappy ones are over-priced and the really good ones are WAY over-priced.

I'd definitely recommend going with Gold, beecause Rhodium plating is a real hassle to do well.

Jahn is right about Silver- It is a great conductor of electricity, but tarnish is a problem; "absolutely pure" silver doesn't tarnish as rapidly as alloys, but even pure silver could eventually become a problem, unless it is going to be in an inert atmosphere.

(the reason that Silver contacts on high current relays and switches don't have a tarnish problem is that the oxides and sulphides are vaporized every time contact is made or broken)

Also, depending upon what the battery contacts are made of, they may have to be copper and/or nickel plated first, as gold plating does not adhere well when directly applied to ferrous and some other metals.

(All of the battery contacts around here that I can test are ferrous, and I don't know if they have been nickel plated or not without testing them chemically.)

Why can't you solder the connections? That would be the best way to go if at all possible. If "failure is not an option" that should overcome any inconvenience or bureaucratic nonsense.

 

[B@rt]

Maybe i'm remembering wrong, but isn't silveroxide even more conductant as pure silver?

 

[PhilAlex]

Thanks for the great info guys...

Ya, these are all "sealed" cells. 2 sets of buttons, and 2 set of alkaline AAA.

I found some cheapo gold plating solution on the web... Gonna give that a try.

BTW: Failure is not an option because I just want this job DONE and OVER. I'm literally firing this client after this job.

And... If I have some gold stuff left over, I'll try my regular batteries... Be nice to have some gold plated AAA's for my ARC.

--Phil

 

[sunspot]

Can gold be directly soldered onto the battery contact area? Maybe a gold/lead alloy?
Just a thought.

 

[JollyRoger]

Maybe even using that highly conductive epoxy (from epoxies.com) usually used in cold soldering applications....you can just "epoxy" the batteries in!