# Battery's negative making contact with inside of mod



## aktorsyl (28/6/17)

Here's a question I've been curious about for some time. The way I understand it, single-18650 mods (regulated, not mechs) have a positive battery pin, and from there it runs insulated all the way to the PCB, whereafter it goes to the positive post on the deck eventually. It's obviously separated from everything else.

The negative side doesn't really go anywhere other than the metal body of the mod? Or does it? Because if it doesn't, why is it considered so dangerous for the wrapping to be damaged near the negative end of the battery if it can't possibly reach the positive pin from there?

I was looking at the SXK BB now, and unless I'm looking at it the wrong way, the negative part of the battery basically just goes onto & into the body of the mod. So the entire outside of the battery, being negative, would have the same effect if it touched anything other than the positive pin, right?

(Theoretical question, obviously I would never tolerate any torn wrappings in my mods)

Reactions: Like 1 | Agree 1


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## Salamander (28/6/17)

Theoretically correct. This only applies to most single battery mods though.


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## aktorsyl (28/6/17)

Salamander said:


> Theoretically correct. This only applies to most single battery mods though.


Right, because in multi-battery mods, the voltage potential across the "range" of batteries would be different on the outer casing of each battery in that range, if they're in series (I assume). If it's a 4-battery mod and the negative of battery #2 touches the body, you suddenly only have 8.4V instead of 16.8V, which will in turn cause the amps to skyrocket (again, I'm assuming).

In the case of a single-battery regulated mod like the BB, however, it shouldn't make any difference if the outer casing of the battery touches the metal part of the mod.

Disclaimer: I'm NOT saying you should use batteries with torn wrappings, please don't do that


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## Salamander (28/6/17)

Correct. In a series set up the Negative (case) of battery 2 is actually not at 0 volts, but at 3.7V and so on. The only part of any cell that can touch the case of the mod is battery No1. Any other cell will be at a higher potential (3.7 then 7.4 and so on). Its more a voltage problem than a current problem as in series the voltage goes up but the amperage stays the same.

Reactions: Thanks 1


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## craigb (28/6/17)

aktorsyl said:


> I'm NOT saying you should use batteries with torn wrappings, please don't do that


Something that does become more relevant the more you repeat it. 

Thanks for this thread @aktorsyl, stuff like this fascinates me, purely from the theoretical point of view.

Reactions: Like 1


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## aktorsyl (28/6/17)

craigb said:


> Something that does become more relevant the more you repeat it.
> 
> Thanks for this thread @aktorsyl, stuff like this fascinates me, purely from the theoretical point of view.


Indeed, you never know when someone is going to act like a chop, have something happen and then afterwards say "but it should've been okay, really".

PS: Nicotine degrades faste....... nah, I think we're over that one now

Reactions: Funny 1


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