Burnt marks on positive and negative sides of a battery...

[Lateralus839]

Hey all I’ve been using two Sony VTC 5A batteries that I got in May in a regulated mod I just noticed that they both have small burnt marks on the positive and negative terminals are they dangerous to use? What causes this?

 

[Rossum]

If they were being used in a mechanical mod with the make/break contact at one end of the battery, I'd say that's normal, an expected result of the arcing that's inevitable in a mechanical switch. But in a regulated mod, I'm at a loss to explain it. What do the contacts in the mod look like? How about the other (negative) end of the cells?

 

[Anise]

Are you sure those are burn marks? Kinda looks like spotting on the wrapper.

 

[Shadav]

I'm no expert but I don't think those are burn marks, looks more like transfer, like black paint got onto it from probably the paint job in the battery compartment

but i'd not take a chance....remove the wrap, check the battery and if it looks good rewrap the battery....

Tutorial: Re-wrapping a battery
How To Rewrap Your 18650 Batteries Tutorial

 

[Baditude]

Are you sure those are burn marks? Kinda looks like spotting on the wrapper.

The dark marks under the insulation wrap in the pic are normal, especially for Sony batteries. The cause for the spots is unclear, but believed to be more commonly seen with Sony batteries because of their use of a semi-transparent wrap. The weird thing is once the wrap is removed, the spots mysteriously disappear.

Your batteries are perfectly normal to use with those spots. No need to rewrap unless the wrap becomes torn or develops a hole.

Slight dark spot on battery | .................. Forums - An Ecig ...
Can someone tell me what these black spots are ...

Dark Spots Showing Under battery Wrap VTC4 & VTC5's 18650 | E ...

 

[puffon]

Send it to me, I'll dispose of it properly.
Looks fine to me....

 

[score69]

This has come up several times here. I've got some VTC4s that are the same way.

Betting that's liquid you can move around with your finger through the wrap.

There's other threads here about Sony batteries that have a mysterious liquid form around the top. It's not a juice leak. I've not really worried about it with mine.

 

[United States]

Mold perhaps?

 

[Lateralus839]

Well there’s black marks on both ends of the battery on the metal parts can’t really take a good pic of the marks for some reason the wrap and stuff is fine and in tact no black marks except by the insulator rings but no tears or anything