Rig Mod Explodes
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This is unlikely. How would a switch get into a position to directly short the positive terminal to the negative terminal. Remember there is the load in between any power terminal and the switch.
Whether the switch is on the positive side or negative side the only thing a shorted switch will
do is be in the always closed position. This is not good either but,it is not a dead short. If the battery was inserted upside down and the switch is between the negative terminal and the load when closed the switch is at the same potential as the negative terminal. No current will flow because there is no difference in potential.
Mike
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I was thinking more in terms of deflecting the center post of an inverted battery. Positive/negative contact is extremely close in this area. (i.e. cap short)
Just a thought
Loose parts or dislodged parts should have been noticed as a mater of course.I was thinking more in terms of deflecting the center post of an inverted battery. Positive/negative contact is extremely close in this area. (i.e. cap short)
Just a thought
Mike
Rock, paper, Scissors, Stars and swords.
I take dynamite, dynamite always wins!
Again, this is a mech mod, the switch is in constant contact with the side of the mod, on or off. Again, IF the switch was set up properly, being tight, the nipple on a button top battery could have easily made contact with the switch, and IF there was a problem with the wrapping on the battery, as shown in the videos, it would have caused a direct short.
People keep trying to think of this as a regulated mod and the switch is an isolator., it's not. Take an ohm meter and touch the top of a mech switch where the battery makes contact, now touch the other lead to the outside of the switch assembly. You WILL see continuity. This means IF the nipple of the battery touches the top of the switch, it's now hot on the body of the mod. IF the wrapping is bad on the battery, and it makes contact with the body of the mod, it's a direct short. No Mosfets, no relays, no fuses to blow, just like taking a wire and touching both ends of the battery, again like in the videos shown earlier.
And again "Hey man, my S#$% don't work, fix it for me!" And again, how many times have you been the smartest person in the local vape shop? As stated before, most aren't hired for their rocket surgery skills, they look good and can talk to people! You want the pimple faced geek, or the chick in the tank top with her "thingies" hanging out? I know who I'd hire, just so I could watch her!
It was meat tongue in cheek. I'm old and broken, married 23yrs. Like I told the neighbor lady today, "I can look in the window, but I can't afford to shop there."
My point was, vape shops don't hire people that know what they are selling, as mentioned earlier in this thread, they hire people with good looks and personality. I'm old, big, hairy and cranky. Do you want me, or someone that dresses nice, has a good smile and people skills? It's retail no matter how you slice it, attractive people sell things, ugly people that know what they are talking about don't.
Where on Earth is the coil?(load)
- terminal to switch. Switch to coil. coil to + terminal. does the coil magically
disappear? And again I already mentioned a torn wrap was the most likely cause.
mike
What if... The top-cap was screwed down too far onto a battery inserted the wrong direction, creating a direct connection with the negative terminal?
Also. The picture looks like it was taken in the woods.
Also. The picture looks like it was taken in the woods.
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Then it completes the circuit and electricity flows causing the mod to auto-fire. The electricity flows in the "wrong" direction, but it still goes through the whole circuit including the coil (load) and discharges the battery at a safe amperage. In order for a hard short to occur, there needs to be a path for electricity to flow that bypasses the coil and "short"(ens) the circuit.
I think that would actually hard-short the mod.
Negative Terminal -> Top-Cap -> Tube -> Button -> Positive-Terminal
Negative Terminal -> Top-Cap -> Tube -> Button -> Positive-Terminal
Not in and of itself - it simply completes a Circuit.
There Must be a Path eliminating the Coil to bring resistance to or near 0.000ohm
..............and with that, ..................Here we go again
Was my master plan all along :>
But seriously. There are two paths. Through the circuit at that point. One through the coil. And one through the tube. The path through the tube would have super-critical-hyper-low resistance. Hard-Short.
But seriously. There are two paths. Through the circuit at that point. One through the coil. And one through the tube. The path through the tube would have super-critical-hyper-low resistance. Hard-Short.
Oh you mean the top cap itself, not the center pin? Then yeah, I guess that would do it. If the center pin was missing. And the insulator was also missing or didn't protrude out past the metal on the underside of the topcap. And the battery jacket were torn so the topcap made contact with the battery can itself. Wait a minute, now we're right back where we started.
If the positive battery connection is on the switch and the negative side of the battery (torn wrapper) is touching the side of the mod, the coil is out of the circuit. The only resistance the battery will see would be it's own internal resistance. What happens if you are installing a battery in your car, you have the negative post attached and are tightening the positive side with a metal wrench. That wrench slips, you turn it too far, etc., and you touch the inner fender? It sparks and gets hot, it's a direct short. The only resistance seen is the batteries internal resistance, and the little resistance from the wrench. That's a "hard short". It's the same with a mod, but the switch is in contact with the body of the mod, so the body is now positively charged, all the time, touch the negative side of the battery to the body of the mod, it will spark and see a hard short. The coil sees no power and is out of the circuit.
It depends upon your personal choice to what margin of safety to incorporate into your build. Since I've had a battery explode in a mech before, I tend to be more conservative with my builds and include what I feel is a margin of safety.
I use a 0.6 ohm build for my 20 amp CDR batteries. Ohm's law calculations say that I'm only using 50% of my batteries amp rating. I understand that if you run your batteries at their upper discharge limit, that this practice ages your batteries at a faster rate. Therefore, your 30 amp battery will soon become a 15 amp battery, or your 20 amp battery will become a 10 amp battery.
Computations From An Ohm's Law Calculator:
1.0 ohm = 4.2 amp draw
0.9 ohm = 4.6 amp draw
0.8 ohm = 5.2 amp draw
0.7 ohms = 6 amp draw
0.6 ohms = 7 amp draw
0.5 ohms = 8.4 amp draw
0.4 ohms = 10.5 amp draw
0.3 ohms = 14.0 amp draw
0.2 ohms = 21.0 amp draw
0.1 ohms = 42.0 amp draw
0.0 ohms = dead short = battery goes into thermal runaway
1.0 ohm = 4.2 amp draw
0.9 ohm = 4.6 amp draw
0.8 ohm = 5.2 amp draw
0.7 ohms = 6 amp draw
0.6 ohms = 7 amp draw
0.5 ohms = 8.4 amp draw
0.4 ohms = 10.5 amp draw
0.3 ohms = 14.0 amp draw
0.2 ohms = 21.0 amp draw
0.1 ohms = 42.0 amp draw
0.0 ohms = dead short = battery goes into thermal runaway
Not long ago I was vaping my mech with the 0.6 ohm RDA build, when my vape suddenly was extremely harsh. I knew it was not a "dry hit", as I had just added e-liquid to the wick. Time to trouble shoot.
First thing I did was check the resistance on my ohm reader. I was surprised to see the reading at 0.1 ohm. I found that one of the post screws were loose, and after tightening it, my resistance was again 0.6 ohm. What caused the post screw to become loose I have no idea. I check my coil resistance with each wick change (every 3 days or so). I hadn't dropped my setup on the floor.
My point here is, had I not routinely used a margin of safety (0.6 ohm), I would have hard-shorted my battery. Had I built to 0.3 or 0.4 ohm instead, a 0.5 ohm drop in resistance would have been a hard short.
We also probably put too much faith into cheap $10 ohm readers to read to a 1/10 or 1/100 of an ohm. Heck, even the $3000 Fluke multimeters need to be re-calibrated on a routine basis to remain precise and accurate.
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