Mech Mod Questions

[spr258]

I have been very interested in mech mods for a while now and have been researching them. I understand the importance of battery safety, ohms law, and proper tools and the dangers associated with them. I know there are many different opinions but I have a couple questions before I start buying all the tools needed to run a mech mod. I have a couple months before I get one and will continue to research before I start using one. From what I have found here is a list of the most important things to have.

1. Good mod that is safe with lock out for the fire button.
2. Good battery from the major manufactures. Sony is first choice but also LG and Samsung
3. Good quality ohm meter. Will be getting a ultimate ohms meter.
4. Good quality battery charger. nitecore/ xtar/ efest


First question is what happens when you run a higher ohm coil compared to the battery that is used? I know the lowest ohm coil you want to run in a mech for a single 18650 battery is around .2 ohms for a 4.2 volt fully charged battery with 20+amps. But what happens when you run a .5-.7 ohm or even a 1-1.3 ohm coil with the same 20+ amp battery? Does the full battery amps get used? Does only what is needed get pulled from the battery? I plan to run at the lowest end a .5 ohm coil. I like how the .7-1 ohm coil works on my regulated mod right now so I don't want to go super low to start with. Should I find a lower amp battery?

Second question is for an everyday vape mod what would you choose and why. I am looking at a stabwood mech with a 99% silver contacts. I can either get a brass or copper tub.

Thanks for any help. I love the stabwood look and want to see how mech mods work but also want to be safe while doing it.

 

[Rossum]

First question is what happens when you run a higher ohm coil compared to the battery that is used? I know the lowest ohm coil you want to run in a mech for a single 18650 battery is around .2 ohms for a 4.2 volt fully charged battery with 20+amps. But what happens when you run a .5-.7 ohm or even a 1-1.3 ohm coil with the same 20+ amp battery? Does the full battery amps get used? Does only what is needed get pulled from the battery? I plan to run at the lowest end a .5 ohm coil. I like how the .7-1 ohm coil works.

Higher resistance draws less current from a fixed voltage source.

Ohm's Law: V=I*R Volts = Amps*Ohms

You know two of these. Volts = 4.2. Ohms = 0.5. Solve for Amps.

Divide both sides of the equation by Ohms. The Ohms on the right cancel out and you're left with:

Volts / Ohms = Amps.

4.2 / 0.5 = 8.4 amps.

 

[spr258]

Higher resistance draws less current from a fixed voltage source.

Ohm's Law: V=I*R Volts = Amps*Ohms

You know two of these. Volts = 4.2. Ohms = 0.5. Solve for Amps.

Divide both sides of the equation by Ohms. The Ohms on the right cancel out and you're left with:

Volts / Ohms = Amps.

4.2 / 0.5 = 8.4 amps.

I understand this. What I don't get is if I have 4.2/.5=8.4 amps. I have a 20 amp battery. 20-8.4=11.6 amps where do the amps go? Do the extra amps not get used? Does the coil only use 8.4 amps? Can having to high of amps cause a problem with the setup? Do I get a battery close to the amps I need? Or is it better to have a higher amp battery for safety?

This might be a really dumb question but not to familiar with electricity and do not want to have a problem.

 

[Rossum]

The "20 amps" from the battery is a limit. A battery supplies voltage. Your load draws current from it. How much current your load draws depends on the voltage being supplied by the battery and the resistance of the load. With a 20 amp battery, you should not exceed 20 amps.

So yes, the 0.5 ohm coil only draws 8.4 amps. No, it doesn't hurt the battery to draw less current than it can supply. In fact, it's quite the opposite; a battery that isn't run hard will last longer. Right now, I'm vaping a VTC5 that's over 3 years old.

I run mechanical squonkers. With a single coil, my builds tend to around 0.75 ohms. With duals, I won't go lower than 0.5. 20 amp batteries are the sweet spot IMO.

In principle, you could get away with a 10A battery, but there's little to be gained by doing so.