New To Mechs

[CrazyChef]

Hey!

I'm doing a trade for a tube mech mod, but have only used regulated in the past. Can one of you fine folks point me in the direction of a decent source of info on using these? I looked around and didn't see a sticky on the subject anywhere. I want to avoid any disinformation, so that's why I'm asking here instead of just using Google. I'll be using Samsung 25R 18650s.


Thanks!
CC

 

[Baditude]

Good choice of batteries.

Just be aware that you will have none of the protection circuitry found on regulated mods. Therefore, you'll have no short circuit protection, no reverse battery protection, and no battery over-discharge protection. YOUR BRAIN becomes your protection circuit. Make sure your tube mech mod has adequate vent holes in case of battery thermal runaway, or your metal tube could become a pipe bomb. If your mech uses a bottom fire button which is lockable, lock it each time you set it down; the lock won't prevent an autofire if you don't set it each time.

Mechanical Mod Safe Usage Guide

Battery Basics for Mods

 

[CrazyChef]

Awesome - Thanks!!!

 

[CrazyChef]

So according to Steam Engine, as long as I stay with builds that are at or above 0.15Ω using the 25Rs , I should be okay? And the lower the resistance, the faster the battery drain? Also, 25Rs should not be used under 2.5V, correct?

 

[Baditude]

IMHO, 1.5 ohm resistance would be pushing the Samsung 25R in a mechanical mod. A 0.15 build will pull 28 amps from the battery, which is over its 20 amp continuous discharge rate.

* Coil amp draw from Ohm's Law calculations for Mechanical Mods:

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

Everyone is free to set their own parameters, and I can only say what mine are. I try to never exceed 50% of the CDR (continuous discharge rating) of a fully charged battery (4.2v). So with a 20 amp battery, that 50% would be 10 amps continuous -- a 10.5 amp draw from a 0.4 ohm coil.

The reason that I place a 50% limit is because as a battery ages the mAh of the battery degrades, as the mAh degrades so does the batteries C rating (amp limit). So down the road, your 20A battery may only be a 10A battery.

You may be placing a lot of faith in a cheap ohm reader in making a precise and accurate reading to a tenth or hundredth of an ohm. The most accurate and recently calibrated digital multimeters can cost over $1000. Most of us are using cheap ohm box meters which may not be that accurate. Is your face or hand worth that inaccuracy?

A loose post screw holding your coil on your RBA can drastically lower your coil resistance by as much as 0.5 ohms (from personal experience).

At the time of this writing (October 2015), there are no mod batteries that can deliver more than 30 amp CDR. Any advertisement of over 30 amps is either marketing hype or a pulse discharge rating (a spec we choose not to use).

The batteries we have available can be quite safe if you use the right batteries for the right application and do not abuse them beyond their recommended amp limit. Most bad battery incidents result from user error, wrong calculations, ignoring safe battery practices, or using a mod without adequate vent holes for a battery which goes into thermal runaway.

A battery venting in thermal runaway will release extremely hot gas, toxic chemicals, and rarely flames. Once this chemical reaction begins, there is no stopping it. The gas can build up inside a mod, and if there is inadequate venting the mod becomes a little pipe bomb.

Yes, the lower the resistance of your build, the harder the drain on the battery. Batteries should not be drained below 2.5 volts.

Lower Ohm Coils Will:

• Heat The Coil Faster
• Produce More Vapor
• Drain The Battery Faster
• Use E-Juice Faster
• Produce A "Warmer" Tasting Vape

Higher Ohm Coils Will:

• Heat The Coil Slower
• Produce Less Vapor
• Provide A “Cooler” Tasting Vape
• Use Less E-Juice
• Prolong Battery Life

 

[CrazyChef]

Can I trust this? It's right below the 20A limit. The 25Rs I have say 3.7V on them.

 

[CrazyChef]

BTW, you are helping me IMMENSELY - thank you!

 

[roxynoodle]

Your batteries will be at 4.2v fresh off the charger. And, no, don't run them down to 2.5v. I change mine out by 3.5v, and wouldn't go any lower than 3.2v myself.

 

[Kprthevapr]

BTW, you are helping me IMMENSELY - thank you!

What kind of mod are you getting?

 

[Kprthevapr]

Your batteries will be at 4.2v fresh off the charger. And, no, don't run them down to 2.5v. I change mine out by 3.5v, and wouldn't go any lower than 3.2v myself.

Most quit working good by 3.5, there's a noticeable difference in the hit when the battery is low in a mech mod

 

[Baditude]

Can I trust this? It's right below the 20A limit. The 25Rs I have say 3.7V on them.

You don't use 3.7 volts in the calculator, you use 4.2 volts, what a fully charged battery is. 3.7 volts is the nominal voltage value of the battery.

Explain It to the Noob: Ohm's Law Calculators

 

[roxynoodle]

Most quit working good by 3.5, there's a noticeable difference in the hit when the battery is low in a mech mod

I agree. I did once run one down to 2.96v though. I didn't think it was possible not to notice, but a Gus Phenomenon is a really fine flavor atty.

 

[Kprthevapr]

I agree. I did once run one down to 2.96v though. I didn't think it was possible not to notice, but a Gus Phenomenon is a really fine flavor atty.

I can tell by the flavor when my battery is low. I use my SMPL's daily and I know I can get close to 3 hours on a battery with the builds I use on my derringers. To test this, I have a Cloupor mini that I got yesterday, I put my atty on it at 41.5w with .32 build, the volts are at 3.67. It takes about 3 hours to get the battery to 10% lol

 

[roxynoodle]

I can tell by the flavor when my battery is low. I use my SMPL's daily and I know I can get close to 3 hours on a battery with the builds I use on my derringers. To test this, I have a Cloupor mini that I got yesterday, I put my atty on it at 41.5w with .32 build, the volts are at 3.67. It takes about 3 hours to get the battery to 10% lol

I do own more than 20 mechs and have a minimum of 10 running at any given time, so while not an expert, I'm pretty experienced. And yet, that one time I didn't notice. Had it been any other tank, surely I would have.

 

[Kprthevapr]

I do own more than 20 mechs and have a minimum of 10 running at any given time, so while not an expert, I'm pretty experienced. And yet, that one time I didn't notice. Had it been any other tank, surely I would have.

I have shinyitis

 

[CrazyChef]

What kind of mod are you getting?

Nothing fancy. Just a Beyond Vape Beacon.

 

[Kprthevapr]

Nothing fancy. Just a Beyond Vape Beacon.

That's a sweet mod! Are ya getting the all copper one?

 

[DaveSignal]

Anyway, if you want to stay below CDR of the battery, .21 or higher builds hit that goal. If you want to use only 50% of the rated CDR (only using 10 amps instead of the rated 20), then you would need to build at .42. A .42 or higher resistance will require using thinner wire (like 26 or 28 gauge). You could get a decent vape with 24 gauge if only building a single coil.

Personally, I build at CDR. I often do builds that draw more amps than CDR. But do what you are comfortable with.

 

[Baditude]

I'm at my sweetspot using 28 gauge Kanthal, dual 1.2 ohm coils (0.6 ohm total resistance), Rayon (cellucotton) wick. Sony VTC4 and Samsung 25-R batteries.

 

[CrazyChef]

That's a sweet mod! Are ya getting the all copper one?

No, black. Here's a copy of the trade picture: