Dents on Eneloop


So I have been using my thrunite ti3 for quite some time however I realise that the bottom of my eneloop is getting dented and scratched up by the bottom of the torchlight spring. Will this be dangerous? Have you encountered such problems?
Anyways to prevent such things from happening?

Thank you!

Maybe post a photo?

Hmm, its still functioning properly. Im thinking its the spring thats too stiff. Maybe the bottom of the Eneloops are softer as compared to the alkaline battery as those alkaline seems not to have any dents at all.

Hopefully, there will not be any negativity with the Eneloop as this was a brand new one!

same thing happened to the eneloop in my AAA keychain light. i put it in the charger and ran a charge/discharge cycle. it seems normal. so i keep using it.

Yeah, thats what i figured too. Did some googling and many people have had such problems with tiny AAA flashlights. Battery crushers they are.

I’m still waiting for my opus v2.1 to come before i can run a charge/discharge cycle. However, all looks fine now with this battery.

Spring repair possible? I have a Tank007 E09. I don’t seem to have your problem, but I notice the spring in my light is bent so that the side of the spring wire contacts the battery. Your picture looks as though the end of the spring wire is making contact.

Just wondering if you could use a hooked wire and pull your spring out. Once out you could adjust the contact point to be kinder and gentler to your batteries. Maybe a little judicious sanding, or if you’re really frisky, to shorten the length with a bit too much compression. Then you could use a wood dowel (maybe a pencil) to put the spring back in.

Of course, anything you do is on your own dime and I will deny all knowledge of your actions. :stuck_out_tongue:

Second opinion. A closer look at your photo in full size on flickr is alarming. It looks as though the spring is actually cutting into the metal on the bottom of the battery. I would hazard a guess that this will eventually puncture the bottom of the cell. And we all know what happens then - the electronic smoke comes out. :open_mouth:

I would have this light towed to your workbench, and not use it until the Doctor can make it right.

Hmm the spring can actually puncture the bottom of the eneloop?!

I think so (if sharp enough). I don’t know how thick the metal is on the cell. But, it’s not much.

Look at your photo. In the 6 o’clock position, you will see a straight line, with a curved line below it. Something like a smile. The straight part is the sharp edge that has actually cut the metal. The curved line looks like a resulting dent.

Ok so I removed the spring, no sharp edges at all however it’s really stiff. Any tips on how to put a solder blob on the top to smoothen it out?

My soldering iron is comatose from lack of use. Maybe a soldering guru could chime in.
I would make sure the very end tip of the spring is not the part that comes in contact with the cell first. If you want to get creative, you could make your own spring. Find a ball-point pen as a donor, and have at it. You have nothing to lose at this point.

Edit: I had ruled out the possibility that your charger was causing this damage. But take a look.

Have not yet charge the battery even once since this is a new eneloop so it’s the spring that’s causing the issue. I have compressed the spring several times using my trusty adjustable spanner then re placing the spring back into the flashlight. Apparently now the tension to tighten the head on the twisty to activate the light becomes so much smoother and easier! I can feel less tension of the spring onto the battery when I twist and change modes. Hopefully this will solve the problems! But need to still research on how to solder a flat blob on the spring to prevent such cases from occurring…

> how to solder a flat blob on the spring

See if you can bend just the very last bit of the spring slightly away from the battery, so there’s no ’gouge” from where the spring was cut.
If you can do that, then the contact is made by the “next to last bit” of the spring wire, which will be a nice long curvy rounded shape.

I’ve stopped quite a few lights from getting gouges on the negative ends of their batteries by doing that tiny little tweak.

You have to be careful gripping the part you want to contact the battery — if you ding it up with plier jaws, then it will have sharp edges.
I used plastic grippers of some sort — been too long to recall exactly what.

Oh and a dab of conductive lubricant (Nyogel) can’t hurt.

On the good side, the NiMH batteries I do have with dings and dimples on the negative end haven’t failed or had any problems in quite a few years of continued use.

A blob might take away the sharp edge, but I would think it will increase pressure on the battery. As above, try to shorten the spring a little by reshaping the last coil. Or have you tried compressing the spring fully, and keeping it fully loaded for a while to see if it will collapse a little? Might give you space to add a blob to take away the sharp edge it clearly must have.

Or change the spring to one that is less stiff.