Ohms law advice

[Narkis]

Hello there,

I’ve been vaping for I think 2 years now and I’ve kinda vaped all the different ways ending with an RDA and kinda put RDAs off for awhile not wanting to deal with dripping etc but it’s been one of my favourite ways to vape No more leaking tanks ....Yay !!

Anyway my question is I want to eventually get into Mech mods or have one at the house to vape on but each time I try and figure out ohms law it just goes over my head with the videos I watch, I was wondering if anyone knows of a video that goes threw the whole process with the gear there using and how they know it’s safe to vape;

Also if Mech mods don’t have watts how do you know it’s safe to vape etc,

Think I may have watched too much and over complicated it myself

Anyway thanks in advance

 

[Mawsley]

1. Buy quality batteries

2. Look at the amp rating of your batteries, this is your safety info source.

Some will argue over the difference between pulse and constant current - but if you consider it as a max then you’ll be operating in safe parameters until you get to grips with everything.

Take it that the maximum you charge a battery to is 4.2v for the benefit of any calculation.

Say your battery is rated for 20A, your coil must be no less than 0.21ohm. (4.2/20)

If the battery is rated 30A, you can build a coil to 0.14ohm (4.2/30)

 

[Slanger]

@Narkis you could always use http://www.steam-engine.org/batt.html then you can experiment with it to get more of an idea.

 

[silk186]

It can be difficult to get as it seems a bit abstract even though it only has 3 components.
Try to find a good analogy that works for you. It doesn't need to be from a vaping site.

 

[Narkis]

Thanks guys

 

[Andy S]

Hello there,

I’ve been vaping for I think 2 years now and I’ve kinda vaped all the different ways ending with an RDA and kinda put RDAs off for awhile not wanting to deal with dripping etc but it’s been one of my favourite ways to vape No more leaking tanks ....Yay !!

Anyway my question is I want to eventually get into Mech mods or have one at the house to vape on but each time I try and figure out ohms law it just goes over my head with the videos I watch, I was wondering if anyone knows of a video that goes threw the whole process with the gear there using and how they know it’s safe to vape;

Also if Mech mods don’t have watts how do you know it’s safe to vape etc,

Think I may have watched too much and over complicated it myself

Anyway thanks in advance

Volts divided by Ohms equals Amps. Base your calculations on the maximum voltage of your battery. I know it won't stay at that voltage but the highest Amp draw will be when the battery is fully charged so you really need to use that as the basis of your calculation.
Next get an Ohms reading from your build. If you're using multiple coils then the reading you're interested in is the one you get when all the coils are installed.
Assuming you charge your battery to 4.2V then the maximum Amp draw from your build will be 4.2 divided by the Ohms. So for example if you have a 0.3 Ohm build, you'll be drawing 14Amps when the battery is fully charged and most of the popular batteries can handle that.
Example 2: If your build is 0.14 Ohms you'll need a 30A battery. Or Two 15A batteries in parallel. And this is why it's important if you're using a dual mech you have to know whether it's series or parallel.

With regard to Watts, it really doesn't matter on a mech mod but if you want to know out of curiosity what the power of your vape is, then Volts squared divided by Ohms equals Watts, but you won't know exactly what the Voltage is. It'll start off at 4.2 or whatever you charged the battery to then it'll drop quite quickly to around 3.7 and stay there or thereabouts for a while. Unlike with a regulated mod which keeps the power constant by increasing the Amp draw as the battery voltage drops, you'll know when your battery is getting low on a mech because your vape won't taste as good and your cloud will get smaller so you know it's time to recharge your battery.

Therre are loads of Ohms Law calculators online... I use this one: http://www.ohmslawcalculator.com/ohms-law-calculator just enter 4.2 Volts, the Ohms reading of your build where it says Resistance, hit the Calculate button and it'll give you the Amps and the Watts and the bit you're interested in is the Amps... that's what you need your battery to be capable of delivering, which leads us to Amp ratings on batteries:
Ignore "pulse" ratings and be wary of a battery that simply says "Maximum" because that will usually be a pulse rating. Pulse ratings have no bearing whatsoever on your requirements in the context of vaping. The only number you're interested in from a safety perspective is the Constant Discharge Rate (CDR).

 

[vapesmarter]

it's not just ohms law there are other things to take into account like make sure the battery wraps are perfect a mech is always on so carrying it around in your pocket like a regulated is a no no

get a good battery charger one that can refresh and test your batteries

when you vent a battery because of a hard short you won't get a second chance

 

[crustyfolker]

@Narkis always check your coils ohm's with a ohm meter twice once after building then again when you replace the cap. If the readings differ then the coils are touching the cap or the cap has pushed them onto the deck . Most of the rest has been said.
My last point is you do know a mech using a 20 amp battery won't push as much power as a 200w regulated mod. I say this as some folks think a mech will create more vapour. Oh and a mech will require regular cleaning of the threads and contacts. One more thing a series mech would be a daft start point so stick to a tube or duel paralell box for a while.

 

[Narkis]

Volts divided by Ohms equals Amps. Base your calculations on the maximum voltage of your battery. I know it won't stay at that voltage but the highest Amp draw will be when the battery is fully charged so you really need to use that as the basis of your calculation.
Next get an Ohms reading from your build. If you're using multiple coils then the reading you're interested in is the one you get when all the coils are installed.
Assuming you charge your battery to 4.2V then the maximum Amp draw from your build will be 4.2 divided by the Ohms. So for example if you have a 0.3 Ohm build, you'll be drawing 14Amps when the battery is fully charged and most of the popular batteries can handle that.
Example 2: If your build is 0.14 Ohms you'll need a 30A battery. Or Two 15A batteries in parallel. And this is why it's important if you're using a dual mech you have to know whether it's series or parallel.

With regard to Watts, it really doesn't matter on a mech mod but if you want to know out of curiosity what the power of your vape is, then Volts squared divided by Ohms equals Watts, but you won't know exactly what the Voltage is. It'll start off at 4.2 or whatever you charged the battery to then it'll drop quite quickly to around 3.7 and stay there or thereabouts for a while. Unlike with a regulated mod which keeps the power constant by increasing the Amp draw as the battery voltage drops, you'll know when your battery is getting low on a mech because your vape won't taste as good and your cloud will get smaller so you know it's time to recharge your battery.

Therre are loads of Ohms Law calculators online... I use this one: http://www.ohmslawcalculator.com/ohms-law-calculator just enter 4.2 Volts, the Ohms reading of your build where it says Resistance, hit the Calculate button and it'll give you the Amps and the Watts and the bit you're interested in is the Amps... that's what you need your battery to be capable of delivering, which leads us to Amp ratings on batteries:
Ignore "pulse" ratings and be wary of a battery that simply says "Maximum" because that will usually be a pulse rating. Pulse ratings have no bearing whatsoever on your requirements in the context of vaping. The only number you're interested in from a safety perspective is the Constant Discharge Rate (CDR).

This was very useful thank you

 

[Narkis]

it's not just ohms law there are other things to take into account like make sure the battery wraps are perfect a mech is always on so carrying it around in your pocket like a regulated is a no no

get a good battery charger one that can refresh and test your batteries

when you vent a battery because of a hard short you won't get a second chance

Yeah I understand that and I know about battery wraps and to check them, may have to get a charger any recommendations ?

I know not to carry it around in my pocket and if I was to get a mech it would be a home use mech wouldn’t be taking it out or anything like that,