SparkFun Forums

[brainwav]

Hi all, I have a outdoor project that required people to insert a AA battery to work it. I do this so that there's no power issue with lasting a long time without being serviced. What I've found is that the battery terminals (flat metal piece and spring) end up rusting making it difficult for people to use it. So then I have to go service it. I was wondering if anyone has had any experience with coating terminal with wire glue or conductive glue to provide a non-rusting coat? I haven't found any wire glue in the store nearby, and thought I'd ask before buying online.

The project is part of something called "Geocaching". It's like treasure hunting with a GPS. The devices are modified flashlights that, when powered, are used as POV LED toys to spell out the coordinates for the next stage in the hunt.

Thanks,
Denis.

[MichaelN]

You can probably get stainless battery terminals, but the real issue is that water must be getting into the contact area. Even if you had stainless contacts, the batteries themselves will corrode eventually. You can get special liquids for cleaning and protecting electrical terminals (eg "DeOxIt" by Caig) that seem to work OK.

I think you need to look at using better flashlights - you can get nice machined aluminum flashlights with o-ring seals for a few dollars (DeOxIt can improve the electrical contact of such flashlights, but you really need the o-rings to keep out moisture).

[brainwav]

I don't have a battery in there now. It's just the terminals. The battery gets inserted for about 5 minutes every month. The flashlight is not really a flashlight anymore. Just a case for my electronics. The flashlight is inside of a small plastic peanut butter container with those thick twist on caps that peanut butter containers have. There must be moisture getting in at some point though.

Where's a good place to get stainless battery terminal for a flashlight? I've got several high end flashlights (>50$). How can I tell if the terminal are stainless steel?

Thanks,
Denis.

[MichaelN]

Where's a good place to get stainless battery terminal for a flashlight? I've got several high end flashlights (>50$). How can I tell if the terminal are stainless steel?.

You can't really tell, as all the terminals seem to be nickel plated. Here's a couple I found at digikey that are stainless:
http://www.digikey.com/product-detail/e ... -ND/315754
http://www.digikey.com/product-detail/e ... ND/2079905

[brainwav]

I don't think that would work into my current design. Do you think they make stainless steel springs? I tried looking it up on Digikey, but they only have nickel-coated spring steel.

Denis.

[MichaelN]

I don't think that would work into my current design. Do you think they make stainless steel springs? I tried looking it up on Digikey, but they only have nickel-coated spring steel.

Those battery holders I linked to use nickel-plated stainless steel (see the datasheets). If all else fails, you could buy them and remove the springs...

[brainwav]

Oh ok, I'm looking for the coil type springs. Those don't have then, just the tab-type springs.
Maybe I can use those ipad pens that have the rubber tips at the end. I hear those are conductive. I'll have to measure their resistance tomorrow. I could use on to cover the tip of the coil-spring. I could buy something from the link above for the other end.

Denis.

[waltr]

Check with McMaster-Carr.
http://www.mcmaster.com/#compression-springs/=ixuh0z

If you can't find the exact spring configuration then wind them yourself from SS spring wire.

[brainwav]

Thanks, those should do! I might still pickup some wire glue to try it out.