1mm 18650 battery extender?

[UncLeJunkLe]

I have a mod that I thought had a damaged chip/PCB. Well it turns out that the spring on the positive battery post has merely gotten weak causing the battery to not contact well and therefore causing the the mod to act funny (when battery gets to about 3.8v or lower, mod just restarts itself when you press the fire button).

I took a strong, thin (1mm thick) magnet and placed it on the negative post of the battery then screwed the cap on and VOILA! - the mod now works as it should regardless if the battery is above or below 3.8V - works just like new, in fact.

So how do I extend the length of the battery by about 1mm without using a magnet?

I looked for 1mm battery extenders, but came up short.

EDITED TO ADD: I'm not a big fan of putting a blob of solder on a battery terminal. Looking for a more versatile solution, like an extender, so I can still use the battery on other mods without sizing issues.

 

[Seiggy]

So that was your problem. I won't have guessed the spring. You might want to look at the 2x700 to 18650 battery sleeves. That may do it for you, but I'm not sure how much room you may have in the battery tube/sled.

 

[UncLeJunkLe]

Well a 2x700 sleeve would never fit, the inside of the battery tube is roughly 19.15mm to 19.25mm. But I guess I could buy one of those sleeves, cut the sleeve off so I'm just left with a disk with the contact, then trim that down enough to fit in the battery tube.

Or I can see if I can find a 15xxx to 18xxx sleeve (or something like that) and do the same, except leaving out the last part of cutting the disk.

However, I think this solution will end in a makeshift extender that is a lot thicker than 1mm, which will result in the batter cape not screwing in the whole way. This would not bother me if the battery door were not at the bottom of the mod.

 

[UncLeJunkLe]

So that was your problem. I won't have guessed the spring.

Me either. What led me to that finding was I decided to violently shake the mod with a battery in it, and sure enough, I could feel/hear a bit of a rattle. Put on the magnet, eliminating the rattle, and I've been using the mod for a few days now, just to prove that was the problem. Vaped it without the magnet and it went back to it's same old quirkiness.

It's just not making good enough contact, but as I said the quirk only happens when the batt gets down to 3.8v or lower. Freshly charged batt is OK.

But I have put the mod away now and will wait to use it when I find a better solution than a magnet.

 

[GOMuniEsq]

Can't you hook the spring and stretch it out a bit?

 

[UncLeJunkLe]

Can't you hook the spring and stretch it out a bit?

Nope. Not without first snipping the soldered wire from the positive pin, then resoldering it when I'm done. It's a real pain. That's why I'm looking for a more immediate (but safe) solution.

When I do ever do go in to do a more permanent job, I'm replacing the spring with one that's a little stiffer (but not too stiff). The one in there is really weak.

 

[Barkuti]

Just in case it still is of service, and since in a mod you need a high current spring, let me recommend some stuff:

1. Silver coated phosphor bronze springs @ Kaidomain, these will compress deform to some extent (check this animated gif from here).
2. Hank Wang's gold plated beryllium copper springs, neat and very conductive but rather short and will also lose a little bit of height.
3. BLF Interest List: EX3 High Current Beryllium Copper Silver Plated springs and SST-20 FD2 95CRI[CLOSED FOR SST-20s). This is a forum thread but contains all the required information to order probably the best springs out there concerning conductivity and mechanical properties. There are small and big springs, and can be combined (small inside big) if extra high currents are a necessity. They barely deform when standalone (edited: gen2 big spring loses considerable height if hard compressed, noticed it in my nephew's flashlight; this is adviced in the forum thread). BlueSwordM is the spring man.