Fuse with mech mod

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Truetopath

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I have a K100 and I use a dual coil trident clone on top. I use an efest 18650 1600mah 30Amp battery. I build anywhere from .4 ohm at the lowest to .8 coils and always make a bed of cotton around the posts to prevent the coil from shifting and contacting any metal. I'm really attentive to constantly checking the trident for shorts with my DMM. I also check my battery regularly and recharge at 3.6 volts left. So my question is, is a fuse or a kick necessary to use with this setup, or is it a good backup plan?


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Baditude

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My personal thought is any extra layer of safety can't hurt in a mechanical mod. Even when you practice good mod/battery safety habits, shorts can and will still occur from the atomizer or within the mod itself beyond your reasonable control. Mechanical and electric components can and will fail - this is why there are fuse boxes or circuit breakers in our homes.

A regulated mod will have superior built-in protective circuitry within its processor, but a mechanical mod has none of that. Some mechanical mods have a collapsable hot spring, which when a battery reaches a specific temperature will cause the spring to melt and collapse ... breaking the electrical circuit. I'm very disappointed that some mechanical mods do not have these springs; they were the only built-in preventative measure against a hard short that a mechanical mod had.

Most mods have vent holes to allow a runaway battery to vent its gases, but that's for preventing your mod from exploding like a pipe bomb, not a preventative measure against a hard short/short circuit. So in essence, mechanical mods have NO safety features. You have to depend upon yourself to recognize the signs of a short circuit and hope that you recognize them before a battery decides to go into thermal meltdown.

I don't recall the specifics, but the various safety fuses available for mods differ in how low they will be effective as far as sub-ohms. Some are single use only, others are multiple use which reset themselves. A Kick will only be effective down to a certain ohm level. This is why I've never been an advocate for sub ohm vaping. It's such a grey area of vaping that IMO the risks outweigh any possible benefits. Sub ohm can push our usual IMR batteries past their limits if you don't know what you are doing. Don't even think about using a protected/unprotected ICR battery with sub ohm - that's an accident waiting to happen.

For the past year, I've pretty much stopped using mechanical mods. Over a year ago I had a protected battery vent violently in a mechanical mod - both the hot spring and the protected circuit in the battery failed to do what they were designed to do. This incident made a major impression on me as it nearly caused a fire at my workplace. At that point I made the personal decision to use primarily my regulated mods for their protective circuitry and to use either the safer IMR or hybrid batteries. I have no interest in doing sub ohm; I'm completely content to use standard resistance coils in all of my juice attachments, including my RBA's. After doing a lot of research on Li-Ion batteries, because of today's modern technology of safe chemistry batteries I've decided there is no reason to use protected ICR batteries for e-cigarette mods.
 
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NicoHolic

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I use pretty much nothing but mechanical mods and don't worry in the least about them. I do take precautions such as using only AW IMR batteries and ALWAYS locking the fire button when not in use. As Baditude experienced, if you put a mechanical in your pocket with an unlocked fire button, it can continue to boil liquid until the mod gets very hot, while never drawing enough current through the hot spring's resistance to cause it to collapse or the battery's protection circuit to cause it to activate. In his case, those things didn't fail to do what they're designed to do, which is to protect against excess current.

I also sub-ohm my REO Grands down to 0.5Ω and take the precaution of ensuring the batteries are rated for more than the expected current. The REOs have a hot spring that will collapse immediately in the event of a short. I also take care when building and wicking coils, and don't worry about enjoying sub-ohm.

It is likely a fuse won't let your sub-ohm coils fire.
 
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AttyPops

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Use an ohms law calculator and check the amp draw against the fuse specs...it varies depending on device. Use a voltage of 4.2 for the "max" freshly charged voltage.

So 4.2 volts and .4 ohms == 10.5 amps and 44.1 watts. Some fuses may "blow" at that level.

I have no idea if your lungs will blow at that level. ;)

BTW...you don't need to use coat-hanger wire to have a good vape. You can build some nice dual coil setups with 30 ga or even 32 ga and get longer battery life too. Up to you.
 

Myrany

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I use pretty much nothing but mechanical mods and don't worry in the least about them. I do take precautions such as using only AW IMR batteries and ALWAYS locking the fire button when not in use. As Baditude experienced, if you put a mechanical in your pocket with an unlocked fire button, it can continue to boil liquid until the mod gets very hot, while never drawing enough current through the hot spring's resistance to cause it to collapse or the battery's protection circuit to cause it to activate. In his case, those things didn't fail to do what they're designed to do, which is to protect against excess current.

I also sub-ohm my REO Grands down to 0.5Ω and take the precaution of ensuring the batteries are rated for more than the expected current. The REOs have a hot spring that will collapse immediately in the event of a short. I also take care when building and wicking coils, and don't worry about enjoying sub-ohm.

It is likely a fuse won't let your sub-ohm coils fire.

I do not sub ohm but I did have an A7 atty on my REO short out badly. It was not the build on the A7 that shorted it was the Atty itself. My Ohms went from 1.75 to .57 in suddenly. Heat spring collapsed in the REO. SO I can vouch that those heat springs do work and work well.

I have since learned that the A7 is prone to the kind of problem I had an threw the thing out. REO + RM2 is what I go with these days. I also added checking my heatspring to make sure it is in good shape to my regular maintenance routine.
 

Truetopath

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I don't think a fuse will work over 7 amps. With a fully charged battery, at .4Ω you're pushing over 10 amps. At .6Ω you're just at 7 amps.

I was thinking the same thing about it tripping the fuse quite regularly.


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SissySpike

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I find the fuse to be a pesky device. I like vaping sub ohms in my RBAs I would certainly not discourage any body from using one. But if you know what your doing and can be sure you build is proper (no Shorts) and you are not exceeding the amp limit of your batteries then its safe to say its not needed.

Again I would state if your not meticulousness about checking for shorts, resistance, and know what your batteries are capable of then your best bet is to use one.
 

Ryedan

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You can only use a fuse down to about 0.7 ohms. You might get another 0.1 out of it, but you can't go anywhere near 0.4.

I run mechanical mods and RBA/RDAs all the time. Been doing it since around March this year. It's very easy to make sure your coil does not draw more power than your battery can supply without getting hot.

However, regardless of what resistance you run in a mech mod, it is impossible to be sure you will never have a hard short. That short will not come from the coil, rather from the atty or the mod itself. IMO there will never be any way of making it impossible for this to happen. When you hard short a IMR battery you have seconds before it starts venting.

I don't use a fuse in my mods. I know the risks, accept them and it's worth it for me. For anyone who is not willing to risk a battery venting in their mod, use a fuse, a protected safer chemistry battery or don't use mechanical devices :thumb:
 
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