My 1.5 ohm coil is tripping my shortstop

[card]

For some reason when I use a 1.5 ohm coil in my Igo L with Efest 18350 800 mAh battery my shortstop fuse is getting tripped up. This happens every time I go below about 1.9 ohms with all my RBAs. The battery should support up to 6.4 amp draw and with this setup the output should be about 2.5 amps. Ohms law A=V/R 3.7v/1.5ohms=2.47 amps. According to my multimeter there is no short and I always test with a dry burn. With the shortstop in the dry burn goes out after a 3-5 second pulse. Any ideas why this is happening? .

Equipment Recap:

sigelei mech #20 Version 2
Caravela Clone mod
Igo L with a 1.5ohm coil
Efest 18350 800 mAh

side note: When I vape without the fuse the bottom spring gets very hot.

 

[pdib]

You just have the one battery? If so, I'd be looking at that.

 

[card]

I have two Efest 18350s and two no name 18650s all of them trip the fuse.

 

[UncleChuck]

Do you have any standard equipment (carto, clearo, disposable atty, etc) in a similar resistance range you could throw on those devices, just to rule out the problem being anything with the coil/build?

And When you list two mechs, I assume that mean this same issue happens with both of them?

Tripping the shortstop means very high current draw. Heating up springs can mean very high current draw AND/OR poor conductivity in that area. Although poor conductivity wouldn't increase the current load as I figure, it would just reduce performance delivered to the coil.

I'd look for something inside the mod that's shorting out, and quadruple check there is no issue with your build.

 

[darkzero]

The Shortop stop uses a thermal fuse. It trips by the heat produced by the high current. If you have areas of the mod that gets abnormally hot (aside from the atty area) that is an idication that there may very likely be poor electrical conductivity issues.

 

[card]

Yeah the spring is the only part of the mod that gets hot and it gets very hot. The battery isn't even getting warm its just the spring.

 

[card]

This only happens when I go below 2.0 ohms roughly. I have one c4 clearo and a few other RDAs set above 2 ohms and they work fine. I'll rebuild at 1.5 a few more times and check with my multimeter just to be sure that there isn't a short.

 

[darkzero]

Since you say the spring is getting hot, which I assume is the ground spring? Check the resistance from the top of the spring to ground on the body to see if you get high resistance.

 

[card]

ok rebuild 1

.6 x .1 mm ribbon kanthal equivalent of 30 ga kanthal
1.5 ohm coil


Dry burn test battery one in sigelei 20: lit up real fast in the center first and spreads to the rest of the coil then tripped in less than a second as soon as entire coil is red.
Dry burn test on battery 2 in sigelei 20: (same battery just the other of the pair): Same results as battery one.
Dry burn test on a 650 mAh ego: Quickly lit up and held first for 5 second pulse, then held for a full 10 second pulse with no problem. The ego battery does not feel warm to the touch.

This apears consistent with the poor conductivity in the mod theory.

 

[card]

Since you say the spring is getting hot, which I assume is the ground spring? Check the resistance from the top of the spring to ground on the body to see if you get high resistance.

When I check the resistance of the spring and bottom cap ground I get an inconsitent reading ranging from 1 ohm to 1.5 ohms, seams to level off closer to 1 ohm.

 

[Statistic]

When I check the resistance of the spring and bottom cap ground I get an inconsitent reading ranging from 1 ohm to 1.5 ohms, seams to level off closer to 1 ohm.

.. ... .

 

[darkzero]

When I check the resistance of the spring and bottom cap ground I get an inconsitent reading ranging from 1 ohm to 1.5 ohms, seams to level off closer to 1 ohm.

Ideally it should be closer to .1-.2 ohms......for the entire mod. That may very well be the issue for the heat, try cleaning, tightening, or any other adjustments that may be possible.

 

[UncleChuck]

So the spring was getting so hot it was wicking heat to the shortstop and tripping it?

Sounds like that mod needs modding in a hurry. I'm sure you could remove the spring from the equation completely if you fiddled with the bottom cap.

 

[D. Waterhouse]

I've been told this spring will fit the Sigelei #20 and I'd highly recommend some Noalox also.

 

[card]

Took the spring out and popped in the no name 18650 with the shortstop on the bottom and it works like a charm now. Need to get a hot spring now so I can use my 18350 batteries in it. Thanks, since I'm new to modding I would have never thought to take out the spring.