Arc AAA design element question

I have not yet seen this question asked, so here goes:

Given that the Arc AAA turns on by essentially compressing the battery between the POS and NEG terminals, and as far as I can see, no springs are involved, wouldn't an Arc AAA eventually be rendered innoperative?

In other words, at some point won't metal fatigue set in when either the POS or NEG terminals in the flashlight become dented (squashed) enough not to make contact with the battery terminals?

The Arc AAA is without a doubt a marvel of engineering, and I want mine (well, ALL 3 of them!) to last forever! But this specific design element has left me wondering, so someone please help me out on this one!

Also, as a tag-on question, what is the best way to clean the positive terminal in the bezel? Pencil eraser (recommended by Peter and Co.) seems to do nothing...the black dot that forms on the POS terminal remains.

The Pos termal of the AAA is just a blob of solder. When it wears down, rip off that foam battery ratainer and rebuild the solder. Easy as that...

I can't even begin to imagine the number of cycles it would take to wear either terminal to the point of non-function. The good news is that if you manage to do it in the next ten years, you'll be presented with a brand new light, courtesy of Arc Flashlights LLC. Maybe that new light will be powered by a fuel-cell even... who knows?

You'll never fatigue the contacts, but you will wear it ever so slightly. What typically happens is that the battery begins to spin with the head before the battery contacts the positive nubbin (via friction with the battery retainer). Since the negative contact is a pretty sharp little nubbin, the battery just rotates on it like a needle bearing - so there is very little friction at that point, and thus very little wear.

If I were you, I wouldn't worry about that aspect of the light at all. My guess is that you'll lose the light or become too old to remember what a flashlight is supposed to do before you ever wear out the contacts.

As for the black dot on the pos contact, it may very well just be a polished smooth spot from contacting the batter terminal. Obviously you'll never clean off the smooth spot. If it doesn't clean off with a pencil erasier, it probably isn't anything to be concerned with. You can trying scratching it with a knife. You have little to lose, as my failful assistant pointed out above. It is nothing but a blob of solder.

Well that's a relief.

If anyone is good at blobbing solder it's me!

As for getting too old to know what a flashlight is for...NEVER! I will just need more and more powerful lights as my vision deteriorates (no doubt this will occur faster then the deterioration of the solder on my Arc!).

In any case, I am glad I have my E2E for when that does happen!

I am lookng forward to the Arc fuel cell light! Peter, what's the eta on THAT!?!?

as my failful assistant pointed out above.

Click to expand...

<font size="2" face="Verdana, Arial">Ahem: That's lovely assistant

I think the ARC AAA has a "spring" provided by the foam retainer. The foam keeps the battery and contact seperated, and compressing the battery against the foam lights the ARC. I may be misunderstanding the question, though.

The foam retainer just keeps the thing from rattling. When you turn it on the retainer is crushed down and the battery is pressed tightly between the + and - contacts.

Yes, a traditional spring in a flashlight holds the battery in constant contact with... well the contacts. A switch is then used to complete the circuit. In the Arc, the battery is held off the positive contact by the "springyness" of the battery retainer. Until that time when you mercilessly crush the retainer and make contact.

Does the Arc AAA have a spring? Yes and no.

Or, to put it another way, the AAA battery is only a certain length, and if the distance between the two contacts is greater than that length, then there is never simultaneous contact on both contacts, even without the foam spacer.

So, when you turn on the ARC, you bring the two contacts closer together until both contacts touch the battery simultaneously.

Regular flashlights with springs have those springs because the distance between the contacts isn't adjustable, so a spring is necessary to make sure contact is maintained.

Anybody not clear on this concept now? I think we can proudly say that we've beaten this idea into submission.

Hey, it's not the first idea I have had that has been beaten into submission!

Thanks for throwing me a beatin' though!

We're here for YOU!

Guys, I have some bad news. One of those ideas has decided to press charges for aggravated assault. The prosecutor is considering special circumstances since we all were proud of it.

Adding a spring would (probably, unless some young brilliant engineer had a different way of doing it...which they do, but it would probably cost a lot more to machine) make the light longer overall...and that's bad, it would have to be just the right spring too: if you put in a spring that was too springy the light would never turn off