Mod safety

[Coolsiggy]

I am new to vaping but with some knowledge of electronics and after experiencing a juice short with a squonk mod where the atty fired continuously I became concern with overall safety of design. Some questions,
1. A lack of moisture resistance does not appear to be a important design consideration?
2. Thermo protection does not seem adequate?
I would have thought that a simple bi-metal thermo switch or thermo fuse would be a big help in preventing battery failures. Great to hear any comments or thoughts.

 

[dwcraig1]

Just a bit curious if your mod is a mechanical or is regulated (with circuit board).

 

[bombastinator]

1. Depends. It is to experienced vapers. Not so much to the new ones or the manufacturers.

2. That sounds like a question for @Mooch . He’s the local battery guru. His blog Mooch's blog | E-Cigarette Forum has a wealth of information about such things. It may even already be there. From what I remember he said that one of the issues of thermal protection in vape gear is it’s thermal protection for the board not the batteries.

 

[greek mule]

I think you are referring to mechanical squonker.Was fire button stuck from juice and after you hit it it didn't repel?
If it is regulated squonker you had juice at CPU?

 

[Punk In Drublic]

There are many safety features designed into a modern chip based mod – how well they are implemented is unknown which is why your first line of safety should always be common sense.

I do not know of any device that offers thermal battery protection. Any device that has thermal protection it will be for the board (chipset). Moisture or liquid resistance adds cost to a device so this is a feature that is not always used. But even with devices that claim liquid resistance I would still proceed on the side of caution – do not let marketing influence a false sense of security.

 

[Coolsiggy]

Just a bit curious if your mod is a mechanical or is regulated (with circuit board).

The mod was a Dovpro Topside with board and display...removed bottle rotated mod vertical so as not spill, of course the battery fell...I jerked and rotated mod horizontal which spilt juice inside the mod....oh so predictable.

 

[Coolsiggy]

A regulated squonk mod should have good moisture sealing. I assume that the atty is fired by semiconductor control which means that a relatively weak signal created by a juice short is all that is required to energize the 510 connector. A 0.1 coil would not take very long to pop a 20 amp battery. If the board had multiple shorts from the juice any current sensing safety could be made inactive. A stand alone thermo fuse near the battery could be a option?
I do not mean to be an alarmist but what happened to me scary and I realized that anyone who panic or slower to react would maybe have been injured.

 

[diagrammatiks]

Juice is not conductive. The topside just seems to be really bad at sealing leaking points. Most squonkers aren’t like that.

 

[bombastinator]

Juice is not conductive.

Gah. You’re right. I missed that bit entirely

 

[dwcraig1]

Juice is not conductive.

My ohm meter begs to differ.

 

[Coolsiggy]

My ohm meter begs to differ.

Of course, like most things electrical Mr Ohm decides, it does not take a great deal of signal to trigger a IC. The juice triggered the mod fact.

 

[diagrammatiks]

My ohm meter begs to differ.

Let’s think about this for a second ok?

Does your rda hard short when you drip on it?

 

[RayofLight62]

Juice is an electricity conductor. To make things worse, many switching circuit are very high impedance, so a very little conductivity can lead to problems.

I have seen mod PCBs built to the most varying standards.
Some have conformal coating with gaskets on the mod buttons and other holes.
Some others have nothing of sort.

A fuse on the PCB (in series with batteries) is mandatory if the device has genuine conformity markings. I have seen fuses only on an handful of brands, with Evolv specifically highlighting it. Innokin is another safe-design brand.

You can only say if a mod is of safe design by physically checking it, since manufacturers do not release service manuals for them.

Safe design is a feature that vape reviewers should cover in their analysis.

 

[dc99]

I would agree that some extra battery protection would be nice. Most boards have protection for the board and while it will disconnect power from the battery it would still be possible to have a battery failure. It would be nice if some of the mod manufacturers would include a safety device on the battery. Not that hard and relatively cheap. There are smd fuses that could be added to the battery sled positive contact with not much trouble. They are however probably to hard for the average person to just add to a mod as they are so small and hard to hand solder. PTC fuses would be great but would take up quite a bit of room for modern day high output mods. Thermo fuses could be added with little trouble. There are boards available to add them as I use them on every mech,pwm mod I build. (look at the "pic of your setup" thread). Just remember, they dont actually trip from the current itself so a 30a trip is just a close guess as to how much power will make it trip. In the case of a short they will trip just fine. The trick is, is wont something as close to the battery as possible for battery protection. A fuse on a board will protect the board but what if there is an issue between the board and battery?

 

[RayofLight62]

Let’s think about this for a second ok?

Does your rda hard short when you drip on it?

The load resistor (connected either to ground or Vdd) for the fire button is typically 100 KOhm.

Therefore, you don't need an hard short, or something in the region of one half - two ohms, to produce a stray activation.
A drop of e-liquid on the fire button (with one millimeter of spacing between the solder joints) would produce an equivalent resistance of few kiloohms, happily activating the mod.

It not a supposition of mine, I actually experienced it in the G-priv mini and the original iStick, following a flood from the an RTA and a Nautilus mini.

On the contrary, a worse flood on the SL class device had no conseguences, because of the device seals, and the board coating.

 

[Coolsiggy]

Let’s think about this for a second ok?

Does your rda hard short when you drip on it?

I am currently using the Profile RDA on a VV Pulse Dual which works fine and reads 0.17 ohms as expected. I will be taking the Topside mod apart for possible repair, initially I did a 24hr soak in iso alcohol which did restore the display and appears normal...have not scrolled the menu yet but the 510 short remains with battery in, without battery it reads 2k ohms both polarity.

 

[dwcraig1]

I've been into mine, the battery positive is attached to the top of the 510 assembly as if one part, I stopped at that point.

 

[Punk In Drublic]

@Coolsiggy - You soaked a device that utilizes rubber seals in iso alcohol? That can’t be good. Isopropyl Alcohol can degrade certain rubbers.

Seems the Topsides biggest attribute was its own worse enemy – there are many reports of internal leaking causing failures of some sort.

Conformal Coating comes in many different grades and is widely used within the electronics industry for it also protects against manufacturing elements. But this does not guarantee protection against liquid damage. With a vaping device the fire button also needs to be fully sealed – any liquid that makes its way into the button (which is quite common) could very well short the contacts – conformal coating becomes useless. Below picture of conformal coating with a Pulse 80 board – the coating can be seen by the run highlighted within the red circle. There have been reports of failures after liquid found its way through the fire button.

There is also a question of QC with conformal coating. Should the coating not fully adhere to its surface, it can create a pocket, trapping liquid which could also lead to failure. Below picture of the coating separating from a DNA board indicated by the arrow.

 

[puffon]

@Coolsiggy - You soaked a device that utilizes rubber seals in iso alcohol? That can’t be good. Isopropyl Alcohol can degrade certain rubbers.

ISO Alcohol is rated good to excellent for exposure to Buna-N and silicone, the most common rubbers used in our mods.
I still would use caution with extended exposure.
And you never know what other rubbers China is using, Polyurethane does not fare well with ISO alcohol.
Chemical Resistance Guide : The O-Ring Store, We make getting O-Rings easy!

 

[Punk In Drublic]

ISO Alcohol is rated good to excellent for exposure to Buna-N and silicone, the most common rubbers used in our mods.
I still would use caution with extended exposure.
And you never know what other rubbers China is using, Polyurethane does not fare well with ISO alcohol.
Chemical Resistance Guide : The O-Ring Store, We make getting O-Rings easy!

Correct – hence my response stated ISO Alcohol can degrade certain rubbers. The question now becomes can we trust the manufacture is using a quality grade Nitrile rubber seal that is void of any additives or fillers that might degrade with long exposure to ISO Alcohol? I know through personal experience that the silicone used with some squonk bottles is of very poor grade containing fillers. We are led to believe this is of food or medical grade and I would bet that many of it is not.